18340 Commits

Author SHA1 Message Date
Linus Torvalds
776edb5931 Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into next
Pull core locking updates from Ingo Molnar:
 "The main changes in this cycle were:

   - reduced/streamlined smp_mb__*() interface that allows more usecases
     and makes the existing ones less buggy, especially in rarer
     architectures

   - add rwsem implementation comments

   - bump up lockdep limits"

* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (33 commits)
  rwsem: Add comments to explain the meaning of the rwsem's count field
  lockdep: Increase static allocations
  arch: Mass conversion of smp_mb__*()
  arch,doc: Convert smp_mb__*()
  arch,xtensa: Convert smp_mb__*()
  arch,x86: Convert smp_mb__*()
  arch,tile: Convert smp_mb__*()
  arch,sparc: Convert smp_mb__*()
  arch,sh: Convert smp_mb__*()
  arch,score: Convert smp_mb__*()
  arch,s390: Convert smp_mb__*()
  arch,powerpc: Convert smp_mb__*()
  arch,parisc: Convert smp_mb__*()
  arch,openrisc: Convert smp_mb__*()
  arch,mn10300: Convert smp_mb__*()
  arch,mips: Convert smp_mb__*()
  arch,metag: Convert smp_mb__*()
  arch,m68k: Convert smp_mb__*()
  arch,m32r: Convert smp_mb__*()
  arch,ia64: Convert smp_mb__*()
  ...
2014-06-03 12:57:53 -07:00
Linus Torvalds
59a3d4c363 Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into next
Pull RCU changes from Ingo Molnar:
 "The main RCU changes in this cycle were:

   - RCU torture-test changes.

   - variable-name renaming cleanup.

   - update RCU documentation.

   - miscellaneous fixes.

   - patch to suppress RCU stall warnings while sysrq requests are being
     processed"

* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (68 commits)
  rcu: Provide API to suppress stall warnings while sysrc runs
  rcu: Variable name changed in tree_plugin.h and used in tree.c
  torture: Remove unused definition
  torture: Remove __init from torture_init_begin/end
  torture: Check for multiple concurrent torture tests
  locktorture: Remove reference to nonexistent Kconfig parameter
  rcutorture: Run rcu_torture_writer at normal priority
  rcutorture: Note diffs from git commits
  rcutorture: Add missing destroy_timer_on_stack()
  rcutorture: Explicitly test synchronous grace-period primitives
  rcutorture:  Add tests for get_state_synchronize_rcu()
  rcutorture: Test RCU-sched primitives in TREE_PREEMPT_RCU kernels
  torture: Use elapsed time to detect hangs
  rcutorture: Check for rcu_torture_fqs creation errors
  torture: Better summary diagnostics for build failures
  torture: Notice if an all-zero cpumask is passed inside a critical section
  rcutorture: Make rcu_torture_reader() use cond_resched()
  sched,rcu: Make cond_resched() report RCU quiescent states
  percpu: Fix raw_cpu_inc_return()
  rcutorture: Export RCU grace-period kthread wait state to rcutorture
  ...
2014-06-03 12:35:05 -07:00
Linus Torvalds
49eb7b0750 TTY/Serial driver patches for 3.16-rc1
Here is the big tty / serial driver pull request for 3.16-rc1.
 
 A variety of different serial driver fixes and updates and additions,
 nothing huge, and no real major core tty changes at all.
 
 All have been in linux-next for a while.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-3.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty into next

Pull tty/serial driver updates from Greg KH:
 "Here is the big tty / serial driver pull request for 3.16-rc1.

  A variety of different serial driver fixes and updates and additions,
  nothing huge, and no real major core tty changes at all.

  All have been in linux-next for a while"

* tag 'tty-3.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (84 commits)
  Revert "serial: imx: remove the DMA wait queue"
  serial: kgdb_nmi: Improve console integration with KDB I/O
  serial: kgdb_nmi: Switch from tasklets to real timers
  serial: kgdb_nmi: Use container_of() to locate private data
  serial: cpm_uart: No LF conversion in put_poll_char()
  serial: sirf: Fix compilation failure
  console: Remove superfluous readonly check
  console: Use explicit pointer type for vc_uni_pagedir* fields
  vgacon: Fix & cleanup refcounting
  ARM: tty: Move HVC DCC assembly to arch/arm
  tty/hvc/hvc_console: Fix wakeup of HVC thread on hvc_kick()
  drivers/tty/n_hdlc.c: replace kmalloc/memset by kzalloc
  vt: emulate 8- and 24-bit colour codes.
  printk/of_serial: fix serial console cessation part way through boot.
  serial: 8250_dma: check the result of TX buffer mapping
  serial: uart: add hw flow control support configuration
  tty/serial: at91: add interrupts for modem control lines
  tty/serial: at91: use mctrl_gpio helpers
  tty/serial: Add GPIOLIB helpers for controlling modem lines
  ARM: at91: gpio: implement get_direction
  ...
2014-06-03 09:01:02 -07:00
Jianyu Zhan
c9482a5bdc kernfs: move the last knowledge of sysfs out from kernfs
There is still one residue of sysfs remaining: the sb_magic
SYSFS_MAGIC. However this should be kernfs user specific,
so this patch moves it out. Kerrnfs user should specify their
magic number while mouting.

Signed-off-by: Jianyu Zhan <nasa4836@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-03 08:11:18 -07:00
Linus Torvalds
5da77761e6 Driver core / kernfs pull request for 3.16-rc1
Here is the "big" pull request for 3.16-rc1.
 Not a lot of changes here, some kernfs work, a revert of a very old
 driver core change that ended up cauing some memory leaks on driver
 probe error paths, and other minor things.
 
 As was pointed out earlier today, one commit here,
 26fc9cd200ec839e0b3095e05ae018f27314e7aa (kernfs: move the last
 knowledge of sysfs out from kernfs) is also needed in your 3.15-final
 branch as well.  If you could cherry-pick it there, it would be most
 appreciated by Andy Lutomirski to prevent a regression there.
 
 All of these have been in linux-next for a while.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-3.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core into next

Pull driver core / kernfs changes from Greg KH:
 "Here is the "big" pull request for 3.16-rc1.

  Not a lot of changes here, some kernfs work, a revert of a very old
  driver core change that ended up cauing some memory leaks on driver
  probe error paths, and other minor things.

  As was pointed out earlier today, one commit here, 26fc9cd200ec
  ("kernfs: move the last knowledge of sysfs out from kernfs") is also
  needed in your 3.15-final branch as well.  If you could cherry-pick it
  there, it would be most appreciated by Andy Lutomirski to prevent a
  regression there.

  All of these have been in linux-next for a while"

* tag 'driver-core-3.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  crypto/nx/nx-842: dev_set_drvdata can no longer fail
  kernfs: move the last knowledge of sysfs out from kernfs
  sysfs: fix attribute_group bin file path on removal
  sysfs.h: don't return a void-valued expression in sysfs_remove_file
  init.h: Update initcall_sync variants to fix build errors
  driver core: Inline dev_set/get_drvdata
  driver core: dev_get_drvdata: Don't check for NULL dev
  driver core: dev_set_drvdata returns void
  driver core: dev_set_drvdata can no longer fail
  driver core: Move driver_data back to struct device
  lib/devres.c: fix checkpatch warnings
  lib/devres.c: use dev in devm_request_and_ioremap
  kobject: Make support for uevent_helper optional.
  kernfs: make kernfs_notify() trigger inotify events too
  kernfs: implement kernfs_root->supers list
2014-06-03 08:07:41 -07:00
Minchan Kim
e317218194 tracing: Print max callstack on stacktrace bug
While I played with my own feature(ex, something on the way to reclaim),
the kernel would easily oops. I guessed that the reason had to do with
stack overflow and wanted to prove it.

I discovered the stack tracer which proved to be very useful for me but
the kernel would oops before my user program gather the information via
"watch cat /sys/kernel/debug/tracing/stack_trace" so I couldn't get any
message from that. What I needed was to have the stack tracer emit the
kernel stack usage before it does the oops so I could find what was
hogging the stack.

This patch shows the callstack of max stack usage right before an oops so
we can find a culprit.

So, the result is as follows.

[ 1116.522206] init: lightdm main process (1246) terminated with status 1
[ 1119.922916] init: failsafe-x main process (1272) terminated with status 1
[ 3887.728131] kworker/u24:1 (6637) used greatest stack depth: 256 bytes left
[ 6397.629227] cc1 (9554) used greatest stack depth: 128 bytes left
[ 7174.467392]         Depth    Size   Location    (47 entries)
[ 7174.467392]         -----    ----   --------
[ 7174.467785]   0)     7248     256   get_page_from_freelist+0xa7/0x920
[ 7174.468506]   1)     6992     352   __alloc_pages_nodemask+0x1cd/0xb20
[ 7174.469224]   2)     6640       8   alloc_pages_current+0x10f/0x1f0
[ 7174.469413]   3)     6632     168   new_slab+0x2c5/0x370
[ 7174.469413]   4)     6464       8   __slab_alloc+0x3a9/0x501
[ 7174.469413]   5)     6456      80   __kmalloc+0x1cb/0x200
[ 7174.469413]   6)     6376     376   vring_add_indirect+0x36/0x200
[ 7174.469413]   7)     6000     144   virtqueue_add_sgs+0x2e2/0x320
[ 7174.469413]   8)     5856     288   __virtblk_add_req+0xda/0x1b0
[ 7174.469413]   9)     5568      96   virtio_queue_rq+0xd3/0x1d0
[ 7174.469413]  10)     5472     128   __blk_mq_run_hw_queue+0x1ef/0x440
[ 7174.469413]  11)     5344      16   blk_mq_run_hw_queue+0x35/0x40
[ 7174.469413]  12)     5328      96   blk_mq_insert_requests+0xdb/0x160
[ 7174.469413]  13)     5232     112   blk_mq_flush_plug_list+0x12b/0x140
[ 7174.469413]  14)     5120     112   blk_flush_plug_list+0xc7/0x220
[ 7174.469413]  15)     5008      64   io_schedule_timeout+0x88/0x100
[ 7174.469413]  16)     4944     128   mempool_alloc+0x145/0x170
[ 7174.469413]  17)     4816      96   bio_alloc_bioset+0x10b/0x1d0
[ 7174.469413]  18)     4720      48   get_swap_bio+0x30/0x90
[ 7174.469413]  19)     4672     160   __swap_writepage+0x150/0x230
[ 7174.469413]  20)     4512      32   swap_writepage+0x42/0x90
[ 7174.469413]  21)     4480     320   shrink_page_list+0x676/0xa80
[ 7174.469413]  22)     4160     208   shrink_inactive_list+0x262/0x4e0
[ 7174.469413]  23)     3952     304   shrink_lruvec+0x3e1/0x6a0
[ 7174.469413]  24)     3648      80   shrink_zone+0x3f/0x110
[ 7174.469413]  25)     3568     128   do_try_to_free_pages+0x156/0x4c0
[ 7174.469413]  26)     3440     208   try_to_free_pages+0xf7/0x1e0
[ 7174.469413]  27)     3232     352   __alloc_pages_nodemask+0x783/0xb20
[ 7174.469413]  28)     2880       8   alloc_pages_current+0x10f/0x1f0
[ 7174.469413]  29)     2872     200   __page_cache_alloc+0x13f/0x160
[ 7174.469413]  30)     2672      80   find_or_create_page+0x4c/0xb0
[ 7174.469413]  31)     2592      80   ext4_mb_load_buddy+0x1e9/0x370
[ 7174.469413]  32)     2512     176   ext4_mb_regular_allocator+0x1b7/0x460
[ 7174.469413]  33)     2336     128   ext4_mb_new_blocks+0x458/0x5f0
[ 7174.469413]  34)     2208     256   ext4_ext_map_blocks+0x70b/0x1010
[ 7174.469413]  35)     1952     160   ext4_map_blocks+0x325/0x530
[ 7174.469413]  36)     1792     384   ext4_writepages+0x6d1/0xce0
[ 7174.469413]  37)     1408      16   do_writepages+0x23/0x40
[ 7174.469413]  38)     1392      96   __writeback_single_inode+0x45/0x2e0
[ 7174.469413]  39)     1296     176   writeback_sb_inodes+0x2ad/0x500
[ 7174.469413]  40)     1120      80   __writeback_inodes_wb+0x9e/0xd0
[ 7174.469413]  41)     1040     160   wb_writeback+0x29b/0x350
[ 7174.469413]  42)      880     208   bdi_writeback_workfn+0x11c/0x480
[ 7174.469413]  43)      672     144   process_one_work+0x1d2/0x570
[ 7174.469413]  44)      528     112   worker_thread+0x116/0x370
[ 7174.469413]  45)      416     240   kthread+0xf3/0x110
[ 7174.469413]  46)      176     176   ret_from_fork+0x7c/0xb0
[ 7174.469413] ------------[ cut here ]------------
[ 7174.469413] kernel BUG at kernel/trace/trace_stack.c:174!
[ 7174.469413] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC
[ 7174.469413] Dumping ftrace buffer:
[ 7174.469413]    (ftrace buffer empty)
[ 7174.469413] Modules linked in:
[ 7174.469413] CPU: 0 PID: 440 Comm: kworker/u24:0 Not tainted 3.14.0+ #212
[ 7174.469413] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[ 7174.469413] Workqueue: writeback bdi_writeback_workfn (flush-253:0)
[ 7174.469413] task: ffff880034170000 ti: ffff880029518000 task.ti: ffff880029518000
[ 7174.469413] RIP: 0010:[<ffffffff8112336e>]  [<ffffffff8112336e>] stack_trace_call+0x2de/0x340
[ 7174.469413] RSP: 0000:ffff880029518290  EFLAGS: 00010046
[ 7174.469413] RAX: 0000000000000030 RBX: 000000000000002f RCX: 0000000000000000
[ 7174.469413] RDX: 0000000000000000 RSI: 000000000000002f RDI: ffffffff810b7159
[ 7174.469413] RBP: ffff8800295182f0 R08: ffffffffffffffff R09: 0000000000000000
[ 7174.469413] R10: 0000000000000001 R11: 0000000000000001 R12: ffffffff82768dfc
[ 7174.469413] R13: 000000000000f2e8 R14: ffff8800295182b8 R15: 00000000000000f8
[ 7174.469413] FS:  0000000000000000(0000) GS:ffff880037c00000(0000) knlGS:0000000000000000
[ 7174.469413] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[ 7174.469413] CR2: 00002acd0b994000 CR3: 0000000001c0b000 CR4: 00000000000006f0
[ 7174.469413] Stack:
[ 7174.469413]  0000000000000000 ffffffff8114fdb7 0000000000000087 0000000000001c50
[ 7174.469413]  0000000000000000 0000000000000000 0000000000000000 0000000000000000
[ 7174.469413]  0000000000000002 ffff880034170000 ffff880034171028 0000000000000000
[ 7174.469413] Call Trace:
[ 7174.469413]  [<ffffffff8114fdb7>] ? get_page_from_freelist+0xa7/0x920
[ 7174.469413]  [<ffffffff816eee3f>] ftrace_call+0x5/0x2f
[ 7174.469413]  [<ffffffff81165065>] ? next_zones_zonelist+0x5/0x70
[ 7174.469413]  [<ffffffff810a23fa>] ? __bfs+0x11a/0x270
[ 7174.469413]  [<ffffffff81165065>] ? next_zones_zonelist+0x5/0x70
[ 7174.469413]  [<ffffffff8114fdb7>] ? get_page_from_freelist+0xa7/0x920
[ 7174.469413]  [<ffffffff8119092f>] ? alloc_pages_current+0x10f/0x1f0
[ 7174.469413]  [<ffffffff811507fd>] __alloc_pages_nodemask+0x1cd/0xb20
[ 7174.469413]  [<ffffffff810a4de6>] ? check_irq_usage+0x96/0xe0
[ 7174.469413]  [<ffffffff816eee3f>] ? ftrace_call+0x5/0x2f
[ 7174.469413]  [<ffffffff8119092f>] alloc_pages_current+0x10f/0x1f0
[ 7174.469413]  [<ffffffff81199cd5>] ? new_slab+0x2c5/0x370
[ 7174.469413]  [<ffffffff81199cd5>] new_slab+0x2c5/0x370
[ 7174.469413]  [<ffffffff816eee3f>] ? ftrace_call+0x5/0x2f
[ 7174.469413]  [<ffffffff816db002>] __slab_alloc+0x3a9/0x501
[ 7174.469413]  [<ffffffff8119af8b>] ? __kmalloc+0x1cb/0x200
[ 7174.469413]  [<ffffffff8141dc46>] ? vring_add_indirect+0x36/0x200
[ 7174.469413]  [<ffffffff8141dc46>] ? vring_add_indirect+0x36/0x200
[ 7174.469413]  [<ffffffff8141dc46>] ? vring_add_indirect+0x36/0x200
[ 7174.469413]  [<ffffffff8119af8b>] __kmalloc+0x1cb/0x200
[ 7174.469413]  [<ffffffff8141de10>] ? vring_add_indirect+0x200/0x200
[ 7174.469413]  [<ffffffff8141dc46>] vring_add_indirect+0x36/0x200
[ 7174.469413]  [<ffffffff8141e402>] virtqueue_add_sgs+0x2e2/0x320
[ 7174.469413]  [<ffffffff8148e35a>] __virtblk_add_req+0xda/0x1b0
[ 7174.469413]  [<ffffffff8148e503>] virtio_queue_rq+0xd3/0x1d0
[ 7174.469413]  [<ffffffff8134aa0f>] __blk_mq_run_hw_queue+0x1ef/0x440
[ 7174.469413]  [<ffffffff8134b0d5>] blk_mq_run_hw_queue+0x35/0x40
[ 7174.469413]  [<ffffffff8134b7bb>] blk_mq_insert_requests+0xdb/0x160
[ 7174.469413]  [<ffffffff8134be5b>] blk_mq_flush_plug_list+0x12b/0x140
[ 7174.469413]  [<ffffffff81342237>] blk_flush_plug_list+0xc7/0x220
[ 7174.469413]  [<ffffffff816e60ef>] ? _raw_spin_unlock_irqrestore+0x3f/0x70
[ 7174.469413]  [<ffffffff816e16e8>] io_schedule_timeout+0x88/0x100
[ 7174.469413]  [<ffffffff816e1665>] ? io_schedule_timeout+0x5/0x100
[ 7174.469413]  [<ffffffff81149415>] mempool_alloc+0x145/0x170
[ 7174.469413]  [<ffffffff8109baf0>] ? __init_waitqueue_head+0x60/0x60
[ 7174.469413]  [<ffffffff811e246b>] bio_alloc_bioset+0x10b/0x1d0
[ 7174.469413]  [<ffffffff81184230>] ? end_swap_bio_read+0xc0/0xc0
[ 7174.469413]  [<ffffffff81184230>] ? end_swap_bio_read+0xc0/0xc0
[ 7174.469413]  [<ffffffff81184110>] get_swap_bio+0x30/0x90
[ 7174.469413]  [<ffffffff81184230>] ? end_swap_bio_read+0xc0/0xc0
[ 7174.469413]  [<ffffffff81184660>] __swap_writepage+0x150/0x230
[ 7174.469413]  [<ffffffff810ab405>] ? do_raw_spin_unlock+0x5/0xa0
[ 7174.469413]  [<ffffffff81184230>] ? end_swap_bio_read+0xc0/0xc0
[ 7174.469413]  [<ffffffff81184515>] ? __swap_writepage+0x5/0x230
[ 7174.469413]  [<ffffffff81184782>] swap_writepage+0x42/0x90
[ 7174.469413]  [<ffffffff8115ae96>] shrink_page_list+0x676/0xa80
[ 7174.469413]  [<ffffffff816eee3f>] ? ftrace_call+0x5/0x2f
[ 7174.469413]  [<ffffffff8115b872>] shrink_inactive_list+0x262/0x4e0
[ 7174.469413]  [<ffffffff8115c1c1>] shrink_lruvec+0x3e1/0x6a0
[ 7174.469413]  [<ffffffff8115c4bf>] shrink_zone+0x3f/0x110
[ 7174.469413]  [<ffffffff816eee3f>] ? ftrace_call+0x5/0x2f
[ 7174.469413]  [<ffffffff8115c9e6>] do_try_to_free_pages+0x156/0x4c0
[ 7174.469413]  [<ffffffff8115cf47>] try_to_free_pages+0xf7/0x1e0
[ 7174.469413]  [<ffffffff81150db3>] __alloc_pages_nodemask+0x783/0xb20
[ 7174.469413]  [<ffffffff8119092f>] alloc_pages_current+0x10f/0x1f0
[ 7174.469413]  [<ffffffff81145c0f>] ? __page_cache_alloc+0x13f/0x160
[ 7174.469413]  [<ffffffff81145c0f>] __page_cache_alloc+0x13f/0x160
[ 7174.469413]  [<ffffffff81146c6c>] find_or_create_page+0x4c/0xb0
[ 7174.469413]  [<ffffffff811463e5>] ? find_get_page+0x5/0x130
[ 7174.469413]  [<ffffffff812837b9>] ext4_mb_load_buddy+0x1e9/0x370
[ 7174.469413]  [<ffffffff81284c07>] ext4_mb_regular_allocator+0x1b7/0x460
[ 7174.469413]  [<ffffffff81281070>] ? ext4_mb_use_preallocated+0x40/0x360
[ 7174.469413]  [<ffffffff816eee3f>] ? ftrace_call+0x5/0x2f
[ 7174.469413]  [<ffffffff81287eb8>] ext4_mb_new_blocks+0x458/0x5f0
[ 7174.469413]  [<ffffffff8127d83b>] ext4_ext_map_blocks+0x70b/0x1010
[ 7174.469413]  [<ffffffff8124e6d5>] ext4_map_blocks+0x325/0x530
[ 7174.469413]  [<ffffffff81253871>] ext4_writepages+0x6d1/0xce0
[ 7174.469413]  [<ffffffff812531a0>] ? ext4_journalled_write_end+0x330/0x330
[ 7174.469413]  [<ffffffff811539b3>] do_writepages+0x23/0x40
[ 7174.469413]  [<ffffffff811d2365>] __writeback_single_inode+0x45/0x2e0
[ 7174.469413]  [<ffffffff811d36ed>] writeback_sb_inodes+0x2ad/0x500
[ 7174.469413]  [<ffffffff811d39de>] __writeback_inodes_wb+0x9e/0xd0
[ 7174.469413]  [<ffffffff811d40bb>] wb_writeback+0x29b/0x350
[ 7174.469413]  [<ffffffff81057c3d>] ? __local_bh_enable_ip+0x6d/0xd0
[ 7174.469413]  [<ffffffff811d6e9c>] bdi_writeback_workfn+0x11c/0x480
[ 7174.469413]  [<ffffffff81070610>] ? process_one_work+0x170/0x570
[ 7174.469413]  [<ffffffff81070672>] process_one_work+0x1d2/0x570
[ 7174.469413]  [<ffffffff81070610>] ? process_one_work+0x170/0x570
[ 7174.469413]  [<ffffffff81071bb6>] worker_thread+0x116/0x370
[ 7174.469413]  [<ffffffff81071aa0>] ? manage_workers.isra.19+0x2e0/0x2e0
[ 7174.469413]  [<ffffffff81078e53>] kthread+0xf3/0x110
[ 7174.469413]  [<ffffffff81078d60>] ? flush_kthread_worker+0x150/0x150
[ 7174.469413]  [<ffffffff816ef0ec>] ret_from_fork+0x7c/0xb0
[ 7174.469413]  [<ffffffff81078d60>] ? flush_kthread_worker+0x150/0x150
[ 7174.469413] Code: c0 49 bc fc 8d 76 82 ff ff ff ff e8 44 5a 5b 00 31 f6 8b 05 95 2b b3 00 48 39 c6 7d 0e 4c 8b 04 f5 20 5f c5 81 49 83 f8 ff 75 11 <0f> 0b 48 63 05 71 5a 64 01 48 29 c3 e9 d0 fd ff ff 48 8d 5e 01
[ 7174.469413] RIP  [<ffffffff8112336e>] stack_trace_call+0x2de/0x340
[ 7174.469413]  RSP <ffff880029518290>
[ 7174.469413] ---[ end trace c97d325b36b718f3 ]---

Link: http://lkml.kernel.org/p/1401683592-1651-1-git-send-email-minchan@kernel.org

Signed-off-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-06-02 16:43:49 -04:00
Linus Torvalds
425553209b PCI changes for the v3.16 merge window:
Enumeration
     - Notify driver before and after device reset (Keith Busch)
     - Use reset notification in NVMe (Keith Busch)
 
   NUMA
     - Warn if we have to guess host bridge node information (Myron Stowe)
     - Work around AMD Fam15h BIOSes that fail to provide _PXM (Suravee Suthikulpanit)
     - Clean up and mark early_root_info_init() as deprecated (Suravee Suthikulpanit)
 
   Driver binding
     - Add "driver_override" for force specific binding (Alex Williamson)
     - Fail "new_id" addition for devices we already know about (Bandan Das)
 
   Resource management
     - Support BAR sizes up to 8GB (Nikhil Rao, Alan Cox)
     - Don't move IORESOURCE_PCI_FIXED resources (Bjorn Helgaas)
     - Mark SBx00 HPET BAR as IORESOURCE_PCI_FIXED (Bjorn Helgaas)
     - Fail safely if we can't handle BARs larger than 4GB (Bjorn Helgaas)
     - Reject BAR above 4GB if dma_addr_t is too small (Bjorn Helgaas)
     - Don't convert BAR address to resource if dma_addr_t is too small (Bjorn Helgaas)
     - Don't set BAR to zero if dma_addr_t is too small (Bjorn Helgaas)
     - Don't print anything while decoding is disabled (Bjorn Helgaas)
     - Don't add disabled subtractive decode bus resources (Bjorn Helgaas)
     - Add resource allocation comments (Bjorn Helgaas)
     - Restrict 64-bit prefetchable bridge windows to 64-bit resources (Yinghai Lu)
     - Assign i82875p_edac PCI resources before adding device (Yinghai Lu)
 
   PCI device hotplug
     - Remove unnecessary "dev->bus" test (Bjorn Helgaas)
     - Use PCI_EXP_SLTCAP_PSN define (Bjorn Helgaas)
     - Fix rphahp endianess issues (Laurent Dufour)
     - Acknowledge spurious "cmd completed" event (Rajat Jain)
     - Allow hotplug service drivers to operate in polling mode (Rajat Jain)
     - Fix cpqphp possible NULL dereference (Rickard Strandqvist)
 
   MSI
     - Replace pci_enable_msi_block() by pci_enable_msi_exact() (Alexander Gordeev)
     - Replace pci_enable_msix() by pci_enable_msix_exact() (Alexander Gordeev)
     - Simplify populate_msi_sysfs() (Jan Beulich)
 
   Virtualization
     - Add Intel Patsburg (X79) root port ACS quirk (Alex Williamson)
     - Mark RTL8110SC INTx masking as broken (Alex Williamson)
 
   Generic host bridge driver
     - Add generic PCI host controller driver (Will Deacon)
 
   Freescale i.MX6
     - Use new clock names (Lucas Stach)
     - Drop old IRQ mapping (Lucas Stach)
     - Remove optional (and unused) IRQs (Lucas Stach)
     - Add support for MSI (Lucas Stach)
     - Fix imx6_add_pcie_port() section mismatch warning (Sachin Kamat)
 
   Renesas R-Car
     - Add gen2 device tree support (Ben Dooks)
     - Use new OF interrupt mapping when possible (Lucas Stach)
     - Add PCIe driver (Phil Edworthy)
     - Add PCIe MSI support (Phil Edworthy)
     - Add PCIe device tree bindings (Phil Edworthy)
 
   Samsung Exynos
     - Remove unnecessary OOM messages (Jingoo Han)
     - Fix add_pcie_port() section mismatch warning (Sachin Kamat)
 
   Synopsys DesignWare
     - Make MSI ISR shared IRQ aware (Lucas Stach)
 
   Miscellaneous
     - Check for broken config space aliasing (Alex Williamson)
     - Update email address (Ben Hutchings)
     - Fix Broadcom CNB20LE unintended sign extension (Bjorn Helgaas)
     - Fix incorrect vgaarb conditional in WARN_ON() (Bjorn Helgaas)
     - Remove unnecessary __ref annotations (Bjorn Helgaas)
     - Add arch/x86/kernel/quirks.c to MAINTAINERS PCI file patterns (Bjorn Helgaas)
     - Fix use of uninitialized MPS value (Bjorn Helgaas)
     - Tidy x86/gart messages (Bjorn Helgaas)
     - Fix return value from pci_user_{read,write}_config_*() (Gavin Shan)
     - Turn pcibios_penalize_isa_irq() into a weak function (Hanjun Guo)
     - Remove unused serial device IDs (Jean Delvare)
     - Use designated initialization in PCI_VDEVICE (Mark Rustad)
     - Fix powerpc NULL dereference in pci_root_buses traversal (Mike Qiu)
     - Configure MPS on ARM (Murali Karicheri)
     - Remove unnecessary includes of <linux/init.h> (Paul Gortmaker)
     - Move Open Firmware devspec attribute to PCI common code (Sebastian Ott)
     - Use pdev->dev.groups for attribute creation on s390 (Sebastian Ott)
     - Remove pcibios_add_platform_entries() (Sebastian Ott)
     - Add new ID for Intel GPU "spurious interrupt" quirk (Thomas Jarosch)
     - Rename pci_is_bridge() to pci_has_subordinate() (Yijing Wang)
     - Add and use new pci_is_bridge() interface (Yijing Wang)
     - Make pci_bus_add_device() void (Yijing Wang)
 
   DMA API
     - Clarify physical/bus address distinction in docs (Bjorn Helgaas)
     - Fix typos in docs (Emilio López)
     - Update dma_pool_create ()and dma_pool_alloc() descriptions (Gioh Kim)
     - Change dma_declare_coherent_memory() CPU address to phys_addr_t (Bjorn Helgaas)
     - Pass GAPSPCI_DMA_BASE CPU & bus address to dma_declare_coherent_memory() (Bjorn Helgaas)
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Merge tag 'pci-v3.16-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci into next

Pull PCI changes from Bjorn Helgaas:
 "Enumeration
    - Notify driver before and after device reset (Keith Busch)
    - Use reset notification in NVMe (Keith Busch)

  NUMA
    - Warn if we have to guess host bridge node information (Myron Stowe)
    - Work around AMD Fam15h BIOSes that fail to provide _PXM (Suravee
      Suthikulpanit)
    - Clean up and mark early_root_info_init() as deprecated (Suravee
      Suthikulpanit)

  Driver binding
    - Add "driver_override" for force specific binding (Alex Williamson)
    - Fail "new_id" addition for devices we already know about (Bandan
      Das)

  Resource management
    - Support BAR sizes up to 8GB (Nikhil Rao, Alan Cox)
    - Don't move IORESOURCE_PCI_FIXED resources (Bjorn Helgaas)
    - Mark SBx00 HPET BAR as IORESOURCE_PCI_FIXED (Bjorn Helgaas)
    - Fail safely if we can't handle BARs larger than 4GB (Bjorn Helgaas)
    - Reject BAR above 4GB if dma_addr_t is too small (Bjorn Helgaas)
    - Don't convert BAR address to resource if dma_addr_t is too small
      (Bjorn Helgaas)
    - Don't set BAR to zero if dma_addr_t is too small (Bjorn Helgaas)
    - Don't print anything while decoding is disabled (Bjorn Helgaas)
    - Don't add disabled subtractive decode bus resources (Bjorn Helgaas)
    - Add resource allocation comments (Bjorn Helgaas)
    - Restrict 64-bit prefetchable bridge windows to 64-bit resources
      (Yinghai Lu)
    - Assign i82875p_edac PCI resources before adding device (Yinghai Lu)

  PCI device hotplug
    - Remove unnecessary "dev->bus" test (Bjorn Helgaas)
    - Use PCI_EXP_SLTCAP_PSN define (Bjorn Helgaas)
    - Fix rphahp endianess issues (Laurent Dufour)
    - Acknowledge spurious "cmd completed" event (Rajat Jain)
    - Allow hotplug service drivers to operate in polling mode (Rajat Jain)
    - Fix cpqphp possible NULL dereference (Rickard Strandqvist)

  MSI
    - Replace pci_enable_msi_block() by pci_enable_msi_exact()
      (Alexander Gordeev)
    - Replace pci_enable_msix() by pci_enable_msix_exact() (Alexander Gordeev)
    - Simplify populate_msi_sysfs() (Jan Beulich)

  Virtualization
    - Add Intel Patsburg (X79) root port ACS quirk (Alex Williamson)
    - Mark RTL8110SC INTx masking as broken (Alex Williamson)

  Generic host bridge driver
    - Add generic PCI host controller driver (Will Deacon)

  Freescale i.MX6
    - Use new clock names (Lucas Stach)
    - Drop old IRQ mapping (Lucas Stach)
    - Remove optional (and unused) IRQs (Lucas Stach)
    - Add support for MSI (Lucas Stach)
    - Fix imx6_add_pcie_port() section mismatch warning (Sachin Kamat)

  Renesas R-Car
    - Add gen2 device tree support (Ben Dooks)
    - Use new OF interrupt mapping when possible (Lucas Stach)
    - Add PCIe driver (Phil Edworthy)
    - Add PCIe MSI support (Phil Edworthy)
    - Add PCIe device tree bindings (Phil Edworthy)

  Samsung Exynos
    - Remove unnecessary OOM messages (Jingoo Han)
    - Fix add_pcie_port() section mismatch warning (Sachin Kamat)

  Synopsys DesignWare
    - Make MSI ISR shared IRQ aware (Lucas Stach)

  Miscellaneous
    - Check for broken config space aliasing (Alex Williamson)
    - Update email address (Ben Hutchings)
    - Fix Broadcom CNB20LE unintended sign extension (Bjorn Helgaas)
    - Fix incorrect vgaarb conditional in WARN_ON() (Bjorn Helgaas)
    - Remove unnecessary __ref annotations (Bjorn Helgaas)
    - Add arch/x86/kernel/quirks.c to MAINTAINERS PCI file patterns
      (Bjorn Helgaas)
    - Fix use of uninitialized MPS value (Bjorn Helgaas)
    - Tidy x86/gart messages (Bjorn Helgaas)
    - Fix return value from pci_user_{read,write}_config_*() (Gavin Shan)
    - Turn pcibios_penalize_isa_irq() into a weak function (Hanjun Guo)
    - Remove unused serial device IDs (Jean Delvare)
    - Use designated initialization in PCI_VDEVICE (Mark Rustad)
    - Fix powerpc NULL dereference in pci_root_buses traversal (Mike Qiu)
    - Configure MPS on ARM (Murali Karicheri)
    - Remove unnecessary includes of <linux/init.h> (Paul Gortmaker)
    - Move Open Firmware devspec attribute to PCI common code (Sebastian Ott)
    - Use pdev->dev.groups for attribute creation on s390 (Sebastian Ott)
    - Remove pcibios_add_platform_entries() (Sebastian Ott)
    - Add new ID for Intel GPU "spurious interrupt" quirk (Thomas Jarosch)
    - Rename pci_is_bridge() to pci_has_subordinate() (Yijing Wang)
    - Add and use new pci_is_bridge() interface (Yijing Wang)
    - Make pci_bus_add_device() void (Yijing Wang)

  DMA API
    - Clarify physical/bus address distinction in docs (Bjorn Helgaas)
    - Fix typos in docs (Emilio López)
    - Update dma_pool_create ()and dma_pool_alloc() descriptions (Gioh Kim)
    - Change dma_declare_coherent_memory() CPU address to phys_addr_t
      (Bjorn Helgaas)
    - Pass GAPSPCI_DMA_BASE CPU & bus address to dma_declare_coherent_memory()
      (Bjorn Helgaas)"

* tag 'pci-v3.16-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (92 commits)
  MAINTAINERS: Add generic PCI host controller driver
  PCI: generic: Add generic PCI host controller driver
  PCI: imx6: Add support for MSI
  PCI: designware: Make MSI ISR shared IRQ aware
  PCI: imx6: Remove optional (and unused) IRQs
  PCI: imx6: Drop old IRQ mapping
  PCI: imx6: Use new clock names
  i82875p_edac: Assign PCI resources before adding device
  ARM/PCI: Call pcie_bus_configure_settings() to set MPS
  PCI: imx6: Fix imx6_add_pcie_port() section mismatch warning
  PCI: Make pci_bus_add_device() void
  PCI: exynos: Fix add_pcie_port() section mismatch warning
  PCI: Introduce new device binding path using pci_dev.driver_override
  PCI: rcar: Add gen2 device tree support
  PCI: cpqphp: Fix possible null pointer dereference
  PCI: rcar: Add R-Car PCIe device tree bindings
  PCI: rcar: Add MSI support for PCIe
  PCI: rcar: Add Renesas R-Car PCIe driver
  PCI: Fix return value from pci_user_{read,write}_config_*()
  PCI: exynos: Remove unnecessary OOM messages
  ...
2014-06-02 12:15:19 -07:00
Daniel Borkmann
3480593131 net: filter: get rid of BPF_S_* enum
This patch finally allows us to get rid of the BPF_S_* enum.
Currently, the code performs unnecessary encode and decode
workarounds in seccomp and filter migration itself when a filter
is being attached in order to overcome BPF_S_* encoding which
is not used anymore by the new interpreter resp. JIT compilers.

Keeping it around would mean that also in future we would need
to extend and maintain this enum and related encoders/decoders.
We can get rid of all that and save us these operations during
filter attaching. Naturally, also JIT compilers need to be updated
by this.

Before JIT conversion is being done, each compiler checks if A
is being loaded at startup to obtain information if it needs to
emit instructions to clear A first. Since BPF extensions are a
subset of BPF_LD | BPF_{W,H,B} | BPF_ABS variants, case statements
for extensions can be removed at that point. To ease and minimalize
code changes in the classic JITs, we have introduced bpf_anc_helper().

Tested with test_bpf on x86_64 (JIT, int), s390x (JIT, int),
arm (JIT, int), i368 (int), ppc64 (JIT, int); for sparc we
unfortunately didn't have access, but changes are analogous to
the rest.

Joint work with Alexei Starovoitov.

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Mircea Gherzan <mgherzan@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Acked-by: Chema Gonzalez <chemag@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-01 22:16:58 -07:00
Linus Torvalds
32439700fe Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Ingo Molnar:
 "Various fixlets, mostly related to the (root-only) SCHED_DEADLINE
  policy, but also a hotplug bug fix and a fix for a NR_CPUS related
  overallocation bug causing a suspend/resume regression"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched: Fix hotplug vs. set_cpus_allowed_ptr()
  sched/cpupri: Replace NR_CPUS arrays
  sched/deadline: Replace NR_CPUS arrays
  sched/deadline: Restrict user params max value to 2^63 ns
  sched/deadline: Change sched_getparam() behaviour vs SCHED_DEADLINE
  sched: Disallow sched_attr::sched_policy < 0
  sched: Make sched_setattr() correctly return -EFBIG
2014-06-01 18:26:59 -07:00
Niv Yehezkel
057b0a7518 PM / hibernate: fixed typo in comment
Fix a trivial comment typo (s/mam/map) in kernel/power/swap.c.

Signed-off-by: Niv Yehezkel <executerx@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-06-01 00:23:07 +02:00
Linus Torvalds
a4bf79eb6a Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull core futex/rtmutex fixes from Thomas Gleixner:
 "Three fixlets for long standing issues in the futex/rtmutex code
  unearthed by Dave Jones syscall fuzzer:

   - Add missing early deadlock detection checks in the futex code
   - Prevent user space from attaching a futex to kernel threads
   - Make the deadlock detector of rtmutex work again

  Looks large, but is more comments than code change"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  rtmutex: Fix deadlock detector for real
  futex: Prevent attaching to kernel threads
  futex: Add another early deadlock detection check
2014-05-31 09:47:55 -07:00
Steven Rostedt (Red Hat)
4c27e756bc tracing: Move locking of trace_cmdline_lock into start/stop seq calls
With the conversion of the saved_cmdlines output to use seq_read, there
is now a race between accessing the values of the saved_cmdlines and
the writing to them. The trace_cmdline_lock needs to be taken at
the start and stop of the seq calls.

A new __trace_find_cmdline() call is created to allow for the look up
to happen without taking the lock.

Fixes: 42584c81c5ad tracing: Have saved_cmdlines use the seq_read infrastructure
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-05-30 13:03:40 -04:00
Steven Rostedt (Red Hat)
379cfdac37 tracing: Try again for saved cmdline if failed due to locking
In order to prevent the saved cmdline cache from being filled when
tracing is not active, the comms are only recorded after a trace event
is recorded.

The problem is, a comm can fail to be recorded if the trace_cmdline_lock
is held. That lock is taken via a trylock to allow it to happen from
any context (including NMI). If the lock fails to be taken, the comm
is skipped. No big deal, as we will try again later.

But! Because of the code that was added to only record after an event,
we may not try again later as the recording is made as a oneshot per
event per CPU.

Only disable the recording of the comm if the comm is actually recorded.

Fixes: 7ffbd48d5cab "tracing: Cache comms only after an event occurred"
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-05-30 09:42:39 -04:00
Yoshihiro YUNOMAE
42584c81c5 tracing: Have saved_cmdlines use the seq_read infrastructure
Current tracing_saved_cmdlines_read() implementation is naive; It allocates
a large buffer, constructs output data to that buffer for each read
operation, and then copies a portion of the buffer to the user space
buffer. This has several issues such as slow memory allocation, high
CPU usage, and even corruption of the output data.

The seq_read infrastructure is made to handle this type of work.
By converting it to use seq_read() the code becomes smaller, simplified,
as well as correct.

Link: http://lkml.kernel.org/p/20140220084431.3839.51793.stgit@yunodevel

Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-05-29 23:08:07 -04:00
Steven Rostedt (Red Hat)
81dc9f0ef2 tracing: Add tracepoint benchmark tracepoint
In order to help benchmark the time tracepoints take, a new config
option is added called CONFIG_TRACEPOINT_BENCHMARK. When this option
is set a tracepoint is created called "benchmark:benchmark_event".
When the tracepoint is enabled, it kicks off a kernel thread that
goes into an infinite loop (calling cond_sched() to let other tasks
run), and calls the tracepoint. Each iteration will record the time
it took to write to the tracepoint and the next iteration that
data will be passed to the tracepoint itself. That is, the tracepoint
will report the time it took to do the previous tracepoint.
The string written to the tracepoint is a static string of 128 bytes
to keep the time the same. The initial string is simply a write of
"START". The second string records the cold cache time of the first
write which is not added to the rest of the calculations.

As it is a tight loop, it benchmarks as hot cache. That's fine because
we care most about hot paths that are probably in cache already.

An example of the output:

     START
     first=3672 [COLD CACHED]
     last=632 first=3672 max=632 min=632 avg=316 std=446 std^2=199712
     last=278 first=3672 max=632 min=278 avg=303 std=316 std^2=100337
     last=277 first=3672 max=632 min=277 avg=296 std=258 std^2=67064
     last=273 first=3672 max=632 min=273 avg=292 std=224 std^2=50411
     last=273 first=3672 max=632 min=273 avg=288 std=200 std^2=40389
     last=281 first=3672 max=632 min=273 avg=287 std=183 std^2=33666

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-05-29 22:49:54 -04:00
Steven Rostedt
2184db46e4 tracing: Print nasty banner when trace_printk() is in use
trace_printk() is used to debug fast paths within the kernel. Places
that gets called in any context (interrupt or NMI) or thousands of
times a second. Something you do not want to do with a printk().

In order to make it completely lockless as it needs a temporary buffer
to handle some of the string formatting, a page is created per cpu for
every context (four per cpu; normal, softirq, irq, NMI).

Since trace_printk() should only be used for debugging purposes,
there's no reason to waste memory on these buffers on a production
system. That means, trace_printk() should never be used unless a
developer is debugging their kernel. There's macro magic to allocate
the buffers if trace_printk() is used anywhere in the kernel.

To help enforce that trace_printk() isn't used outside of development,
when it is used, a nasty banner is displayed on bootup (or when a module
is loaded that uses trace_printk() and the kernel core does not).

Here's the banner:

 **********************************************************
 **   NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE   **
 **                                                      **
 ** trace_printk() being used. Allocating extra memory.  **
 **                                                      **
 ** This means that this is a DEBUG kernel and it is     **
 ** unsafe for produciton use.                           **
 **                                                      **
 ** If you see this message and you are not debugging    **
 ** the kernel, report this immediately to your vendor!  **
 **                                                      **
 **   NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE   **
 **********************************************************

That should hopefully keep developers from trying to sneak in a
trace_printk() or two.

Link: http://lkml.kernel.org/p/20140528131440.2283213c@gandalf.local.home

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-05-29 20:13:59 -04:00
Stephen Chivers
7fa21dd8bd printk/of_serial: fix serial console cessation part way through boot.
Commit 5f5c9ae56c38942623f69c3e6dc6ec78e4da2076
"serial_core: Unregister console in uart_remove_one_port()"
fixed a crash where a serial port was removed but
not deregistered as a console.

There is a side effect of that commit for platforms having serial consoles
and of_serial configured (CONFIG_SERIAL_OF_PLATFORM). The serial console
is disabled midway through the boot process.

This cessation of the serial console affects PowerPC computers
such as the MVME5100 and SAM440EP.

The sequence is:

	bootconsole [udbg0] enabled
	....
	serial8250/16550 driver initialises and registers its UARTS,
	one of these is the serial console.
	console [ttyS0] enabled
	....
	of_serial probes "platform" devices, registering them as it goes.
	One of these is the serial console.
	console [ttyS0] disabled.

The disabling of the serial console is due to:

	a.  unregister_console in printk not clearing the
	    CONS_ENABLED bit in the console flags,
	    even though it has announced that the console is disabled; and

	b.  of_platform_serial_probe in of_serial not setting the port type
	    before it registers with serial8250_register_8250_port.

This patch ensures that the serial console is re-enabled when of_serial
registers a serial port that corresponds to the designated console.

Signed-off-by: Stephen Chivers <schivers@csc.com>
Tested-by: Stephen Chivers <schivers@csc.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> [unregister_console]
Cc: stable <stable@vger.kernel.org> # 3.15

===
The above failure was identified in Linux-3.15-rc2.

Tested using MVME5100 and SAM440EP PowerPC computers with
kernels built from Linux-3.15-rc5 and tty-next.

The continued operation of the serial console is vital for computers
such as the MVME5100 as that Single Board Computer does not
have any grapical/display hardware.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-28 13:07:27 -07:00
Thomas Gleixner
397335f004 rtmutex: Fix deadlock detector for real
The current deadlock detection logic does not work reliably due to the
following early exit path:

	/*
	 * Drop out, when the task has no waiters. Note,
	 * top_waiter can be NULL, when we are in the deboosting
	 * mode!
	 */
	if (top_waiter && (!task_has_pi_waiters(task) ||
			   top_waiter != task_top_pi_waiter(task)))
		goto out_unlock_pi;

So this not only exits when the task has no waiters, it also exits
unconditionally when the current waiter is not the top priority waiter
of the task.

So in a nested locking scenario, it might abort the lock chain walk
and therefor miss a potential deadlock.

Simple fix: Continue the chain walk, when deadlock detection is
enabled.

We also avoid the whole enqueue, if we detect the deadlock right away
(A-A). It's an optimization, but also prevents that another waiter who
comes in after the detection and before the task has undone the damage
observes the situation and detects the deadlock and returns
-EDEADLOCK, which is wrong as the other task is not in a deadlock
situation.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20140522031949.725272460@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-05-28 17:28:13 +02:00
Linus Torvalds
9e3d633178 Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc
Pull two powerpc fixes from Ben Herrenschmidt:
 "Here's a pair of powerpc fixes for 3.15 which are also going to
  stable.

  One's a fix for building with newer binutils (the problem currently
  only affects the BookE kernels but the affected macro might come back
  into use on BookS platforms at any time).  Unfortunately, the binutils
  maintainer did a backward incompatible change to a construct that we
  use so we have to add Makefile check.

  The other one is a fix for CPUs getting stuck in kexec when running
  single threaded.  Since we routinely use kexec on power (including in
  our newer bootloaders), I deemed that important enough"

* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
  powerpc, kexec: Fix "Processor X is stuck" issue during kexec from ST mode
  powerpc: Fix 64 bit builds with binutils 2.24
2014-05-28 08:06:50 -07:00
Valdis Kletnieks
015af06e10 kernel/workqueue.c: pr_warning/pr_warn & printk/pr_info
This commit did an incorrect printk->pr_info conversion. If we were
converting to pr_info() we should lose the log_level parameter. The problem is
that this is called (indirectly) by show_regs_print_info(), which is called
with various log_levels (from _INFO clear to _EMERG). So we leave it as
a printk() call so the desired log_level is applied.

Not a full revert, as the other half of the patch is correct.

Signed-off-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Signed-off-by: Tejun Heo <tj@kernel.org>
2014-05-28 10:22:34 -04:00
Srivatsa S. Bhat
011e4b02f1 powerpc, kexec: Fix "Processor X is stuck" issue during kexec from ST mode
If we try to perform a kexec when the machine is in ST (Single-Threaded) mode
(ppc64_cpu --smt=off), the kexec operation doesn't succeed properly, and we
get the following messages during boot:

[    0.089866] POWER8 performance monitor hardware support registered
[    0.089985] power8-pmu: PMAO restore workaround active.
[    5.095419] Processor 1 is stuck.
[   10.097933] Processor 2 is stuck.
[   15.100480] Processor 3 is stuck.
[   20.102982] Processor 4 is stuck.
[   25.105489] Processor 5 is stuck.
[   30.108005] Processor 6 is stuck.
[   35.110518] Processor 7 is stuck.
[   40.113369] Processor 9 is stuck.
[   45.115879] Processor 10 is stuck.
[   50.118389] Processor 11 is stuck.
[   55.120904] Processor 12 is stuck.
[   60.123425] Processor 13 is stuck.
[   65.125970] Processor 14 is stuck.
[   70.128495] Processor 15 is stuck.
[   75.131316] Processor 17 is stuck.

Note that only the sibling threads are stuck, while the primary threads (0, 8,
16 etc) boot just fine. Looking closer at the previous step of kexec, we observe
that kexec tries to wakeup (bring online) the sibling threads of all the cores,
before performing kexec:

[ 9464.131231] Starting new kernel
[ 9464.148507] kexec: Waking offline cpu 1.
[ 9464.148552] kexec: Waking offline cpu 2.
[ 9464.148600] kexec: Waking offline cpu 3.
[ 9464.148636] kexec: Waking offline cpu 4.
[ 9464.148671] kexec: Waking offline cpu 5.
[ 9464.148708] kexec: Waking offline cpu 6.
[ 9464.148743] kexec: Waking offline cpu 7.
[ 9464.148779] kexec: Waking offline cpu 9.
[ 9464.148815] kexec: Waking offline cpu 10.
[ 9464.148851] kexec: Waking offline cpu 11.
[ 9464.148887] kexec: Waking offline cpu 12.
[ 9464.148922] kexec: Waking offline cpu 13.
[ 9464.148958] kexec: Waking offline cpu 14.
[ 9464.148994] kexec: Waking offline cpu 15.
[ 9464.149030] kexec: Waking offline cpu 17.

Instrumenting this piece of code revealed that the cpu_up() operation actually
fails with -EBUSY. Thus, only the primary threads of all the cores are online
during kexec, and hence this is a sure-shot receipe for disaster, as explained
in commit e8e5c2155b (powerpc/kexec: Fix orphaned offline CPUs across kexec),
as well as in the comment above wake_offline_cpus().

It turns out that cpu_up() was returning -EBUSY because the variable
'cpu_hotplug_disabled' was set to 1; and this disabling of CPU hotplug was done
by migrate_to_reboot_cpu() inside kernel_kexec().

Now, migrate_to_reboot_cpu() was originally written with the assumption that
any further code will not need to perform CPU hotplug, since we are anyway in
the reboot path. However, kexec is clearly not such a case, since we depend on
onlining CPUs, atleast on powerpc.

So re-enable cpu-hotplug after returning from migrate_to_reboot_cpu() in the
kexec path, to fix this regression in kexec on powerpc.

Also, wrap the cpu_up() in powerpc kexec code within a WARN_ON(), so that we
can catch such issues more easily in the future.

Fixes: c97102ba963 (kexec: migrate to reboot cpu)
Cc: stable@vger.kernel.org
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-05-28 13:24:26 +10:00
Jianyu Zhan
26fc9cd200 kernfs: move the last knowledge of sysfs out from kernfs
There is still one residue of sysfs remaining: the sb_magic
SYSFS_MAGIC. However this should be kernfs user specific,
so this patch moves it out. Kerrnfs user should specify their
magic number while mouting.

Signed-off-by: Jianyu Zhan <nasa4836@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-27 14:33:17 -07:00
Jiang Liu
a257954bb3 genirq: Improve documentation to match current implementation
Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Jiri Kosina <trivial@kernel.org>
Link: http://lkml.kernel.org/r/1401178092-1228-3-git-send-email-jiang.liu@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-05-27 10:16:44 +02:00
Rafael J. Wysocki
0399d4db3e PM / sleep: Introduce command line argument for sleep state enumeration
On some systems the platform doesn't support neither
PM_SUSPEND_MEM nor PM_SUSPEND_STANDBY, so PM_SUSPEND_FREEZE is the
only available system sleep state.  However, some user space frameworks
only use the "mem" and (sometimes) "standby" sleep state labels, so
the users of those systems need to modify user space in order to be
able to use system suspend at all and that is not always possible.

For this reason, add a new kernel command line argument,
relative_sleep_states, allowing the users of those systems to change
the way in which the kernel assigns labels to system sleep states.
Namely, for relative_sleep_states=1, the "mem", "standby" and "freeze"
labels will enumerate the available system sleem states from the
deepest to the shallowest, respectively, so that "mem" is always
present in /sys/power/state and the other state strings may or may
not be presend depending on what is supported by the platform.

Update system sleep states documentation to reflect this change.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-05-26 13:40:59 +02:00
Rafael J. Wysocki
43e8317b0b PM / sleep: Use valid_state() for platform-dependent sleep states only
Use the observation that, for platform-dependent sleep states
(PM_SUSPEND_STANDBY, PM_SUSPEND_MEM), a given state is either
always supported or always unsupported and store that information
in pm_states[] instead of calling valid_state() every time we
need to check it.

Also do not use valid_state() for PM_SUSPEND_FREEZE, which is always
valid, and move the pm_test_level validity check for PM_SUSPEND_FREEZE
directly into enter_state().

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-05-26 13:40:53 +02:00
Rafael J. Wysocki
27ddcc6596 PM / sleep: Add state field to pm_states[] entries
To allow sleep states corresponding to the "mem", "standby" and
"freeze" lables to be different from the pm_states[] indexes of
those strings, introduce struct pm_sleep_state, consisting of
a string label and a state number, and turn pm_states[] into an
array of objects of that type.

This modification should not lead to any functional changes.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-05-26 13:40:47 +02:00
Victor Kamensky
72e6ae285a ARM: 8043/1: uprobes need icache flush after xol write
After instruction write into xol area, on ARM V7
architecture code need to flush dcache and icache to sync
them up for given set of addresses. Having just
'flush_dcache_page(page)' call is not enough - it is
possible to have stale instruction sitting in icache
for given xol area slot address.

Introduce arch_uprobe_ixol_copy weak function
that by default calls uprobes copy_to_page function and
than flush_dcache_page function and on ARM define new one
that handles xol slot copy in ARM specific way

flush_uprobe_xol_access function shares/reuses implementation
with/of flush_ptrace_access function and takes care of writing
instruction to user land address space on given variety of
different cache types on ARM CPUs. Because
flush_uprobe_xol_access does not have vma around
flush_ptrace_access was split into two parts. First that
retrieves set of condition from vma and common that receives
those conditions as flags.

Note ARM cache flush function need kernel address
through which instruction write happened, so instead
of using uprobes copy_to_page function changed
code to explicitly map page and do memcpy.

Note arch_uprobe_copy_ixol function, in similar way as
copy_to_user_page function, has preempt_disable/preempt_enable.

Signed-off-by: Victor Kamensky <victor.kamensky@linaro.org>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: David A. Long <dave.long@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-05-25 23:48:45 +01:00
David S. Miller
54e5c4def0 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	drivers/net/bonding/bond_alb.c
	drivers/net/ethernet/altera/altera_msgdma.c
	drivers/net/ethernet/altera/altera_sgdma.c
	net/ipv6/xfrm6_output.c

Several cases of overlapping changes.

The xfrm6_output.c has a bug fix which overlaps the renaming
of skb->local_df to skb->ignore_df.

In the Altera TSE driver cases, the register access cleanups
in net-next overlapped with bug fixes done in net.

Similarly a bug fix to send ALB packets in the bonding driver using
the right source address overlaps with cleanups in net-next.

Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-24 00:32:30 -04:00
Thomas Gleixner
309179fabd Merge branch 'fortglx/3.16/time' of git://git.linaro.org/people/john.stultz/linux into timers/core
* Remove the deprecated setup_sched_clock() API
* Minor NTP updates
2014-05-24 02:05:51 +02:00
Linus Torvalds
f02f79dbcb Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Ingo Molnar:
 "The biggest commit is an irqtime accounting loop latency fix, the rest
  are misc fixes all over the place: deadline scheduling, docs, numa,
  balancer and a bad to-idle latency fix"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/numa: Initialize newidle balance stats in sd_numa_init()
  sched: Fix updating rq->max_idle_balance_cost and rq->next_balance in idle_balance()
  sched: Skip double execution of pick_next_task_fair()
  sched: Use CPUPRI_NR_PRIORITIES instead of MAX_RT_PRIO in cpupri check
  sched/deadline: Fix memory leak
  sched/deadline: Fix sched_yield() behavior
  sched: Sanitize irq accounting madness
  sched/docbook: Fix 'make htmldocs' warnings caused by missing description
2014-05-23 10:04:04 -07:00
Linus Torvalds
e6a32c3ad1 Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Ingo Molnar:
 "The biggest changes are fixes for races that kept triggering Trinity
  crashes, plus liblockdep build fixes and smaller misc fixes.

  The liblockdep bits in perf/urgent are a pull mistake - they should
  have been in locking/urgent - but by the time I noticed other commits
  were added and testing was done :-/ Sorry about that"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf: Fix a race between ring_buffer_detach() and ring_buffer_attach()
  perf: Prevent false warning in perf_swevent_add
  perf: Limit perf_event_attr::sample_period to 63 bits
  tools/liblockdep: Remove all build files when doing make clean
  tools/liblockdep: Build liblockdep from tools/Makefile
  perf/x86/intel: Fix Silvermont's event constraints
  perf: Fix perf_event_init_context()
  perf: Fix race in removing an event
2014-05-23 10:02:34 -07:00
Bjorn Helgaas
e4c7296643 resources: Clarify sanity check message
The resource map sanity check message is a bit confusing.  Change it to be
more readable:

  -resource map sanity check conflict: 0xfed10000 0xfed15fff 0xfed10000 0xfed13fff pnp 00:01
  +resource sanity check: requesting [mem 0xfed10000-0xfed15fff], which spans more than pnp 00:01 [mem 0xfed10000-0xfed13fff]

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2014-05-23 10:47:21 -06:00
Greg Kroah-Hartman
cbfef53360 Merge 3.15-rc6 into driver-core-next
We want the kernfs fixes in this branch as well for testing.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-23 10:13:53 +09:00
Lai Jiangshan
74b414ead1 workqueue: remove the confusing POOL_FREEZING
Currently, the global freezing state is propagated to worker_pools via
POOL_FREEZING and then to each workqueue; however, the middle step -
propagation through worker_pools - can be skipped as long as one or
more max_active adjustments happens for each workqueue after the
update to the global state is visible.  The global workqueue freezing
state and the max_active adjustments during workqueue creation and
[un]freezing are serialized with wq_pool_mutex, so it's trivial to
guarantee that max_actives stay in sync with global freezing state.

POOL_FREEZING is unnecessary and makes the code more confusing and
complicates freeze_workqueues_begin() and thaw_workqueues() by
requiring them to walk through all pools.

Remove POOL_FREEZING and use workqueue_freezing directly instead.

tj: Description and comment updates.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2014-05-22 11:35:51 -04:00
Lai Jiangshan
1037de36ed workqueue: rename first_worker() to first_idle_worker()
first_worker() actually returns the first idle workers, the name
first_idle_worker() which is self-commnet will be better.

All the callers of first_worker() expect it returns an idle worker,
the name first_idle_worker() with "idle" notation makes reviewers happier.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2014-05-22 11:35:51 -04:00
Ingo Molnar
e14505a8d5 Merge branch 'rcu/next' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu
Pull RCU updates from Paul E. McKenney:

" 1.      Update RCU documentation.  These were posted to LKML at
          https://lkml.org/lkml/2014/4/28/634.

  2.      Miscellaneous fixes.  These were posted to LKML at
          https://lkml.org/lkml/2014/4/28/645.

  3.      Torture-test changes.  These were posted to LKML at
          https://lkml.org/lkml/2014/4/28/667.

  4.      Variable-name renaming cleanup, sent separately due to conflicts.
          This was posted to LKML at https://lkml.org/lkml/2014/5/13/854.

  5.      Patch to suppress RCU stall warnings while sysrq requests are
          being processed.  This patch is the RCU portions of the patch
          that Rik posted to LKML at https://lkml.org/lkml/2014/4/29/457.
          The reason for pushing this patch ahead instead of waiting until
          3.17 is that the NMI-based stack traces are messing up sysrq
          output, and in some cases also messing up the system as well."

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-05-22 11:36:10 +02:00
Rik van Riel
096aa33863 sched/numa: Decay ->wakee_flips instead of zeroing
Affine wakeups have the potential to interfere with NUMA placement.
If a task wakes up too many other tasks, affine wakeups will get
disabled.

However, regardless of how many other tasks it wakes up, it gets
re-enabled once a second, potentially interfering with NUMA
placement of other tasks.

By decaying wakee_wakes in half instead of zeroing it, we can avoid
that problem for some workloads.

Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: chegu_vinod@hp.com
Cc: umgwanakikbuti@gmail.com
Link: http://lkml.kernel.org/r/20140516001332.67f91af2@annuminas.surriel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-05-22 11:16:41 +02:00
Rik van Riel
b1ad065e65 sched/numa: Update migrate_improves/degrades_locality()
Update the migrate_improves/degrades_locality() functions with
knowledge of pseudo-interleaving.

Do not consider moving tasks around within the set of group's active
nodes as improving or degrading locality. Instead, leave the load
balancer free to balance the load between a numa_group's active nodes.

Also, switch from the group/task_weight functions to the group/task_fault
functions. The "weight" functions involve a division, but both calls use
the same divisor, so there's no point in doing that from these functions.

On a 4 node (x10 core) system, performance of SPECjbb2005 seems
unaffected, though the number of migrations with 2 8-warehouse wide
instances seems to have almost halved, due to the scheduler running
each instance on a single node.

Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: mgorman@suse.de
Cc: chegu_vinod@hp.com
Link: http://lkml.kernel.org/r/20140515130306.61aae7db@cuia.bos.redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-05-22 11:16:39 +02:00
Rik van Riel
e63da03639 sched/numa: Allow task switch if load imbalance improves
Currently the NUMA balancing code only allows moving tasks between NUMA
nodes when the load on both nodes is in balance. This breaks down when
the load was imbalanced to begin with.

Allow tasks to be moved between NUMA nodes if the imbalance is small,
or if the new imbalance is be smaller than the original one.

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: mgorman@suse.de
Cc: chegu_vinod@hp.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: http://lkml.kernel.org/r/20140514132221.274b3463@annuminas.surriel.com
2014-05-22 11:16:38 +02:00
xiaofeng.yan
4027d08085 sched/rt: Fix 'struct sched_dl_entity' and dl_task_time() comments, to match the current upstream code
Signed-off-by: xiaofeng.yan <xiaofeng.yan@huawei.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1399605687-18094-1-git-send-email-xiaofeng.yan@huawei.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-05-22 11:16:37 +02:00
Dongsheng Yang
7aa2c016db sched: Consolidate open coded implementations of nice level frobbing into nice_to_rlimit() and rlimit_to_nice()
Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/a568a1e3cc8e78648f41b5035fa5e381d36274da.1399532322.git.yangds.fnst@cn.fujitsu.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-05-22 11:16:36 +02:00
Corey Minyard
a803f0261b sched: Initialize rq->age_stamp on processor start
If the sched_clock time starts at a large value, the kernel will spin
in sched_avg_update for a long time while rq->age_stamp catches up
with rq->clock.

The comment in kernel/sched/clock.c says that there is no strict promise
that it starts at zero.  So initialize rq->age_stamp when a cpu starts up
to avoid this.

I was seeing long delays on a simulator that didn't start the clock at
zero.  This might also be an issue on reboots on processors that don't
re-initialize the timer to zero on reset, and when using kexec.

Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1399574859-11714-1-git-send-email-minyard@acm.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-05-22 11:16:35 +02:00
Kirill Tkhai
7246544786 sched, nohz: Change rq->nr_running to always use wrappers
Sometimes ->nr_running may cross 2 but interrupt is not being
sent to rq's cpu. In this case we don't reenable the timer.
Looks like this may be the reason for rare unexpected effects,
if nohz is enabled.

Patch replaces all places of direct changing of nr_running
and makes add_nr_running() caring about crossing border.

Signed-off-by: Kirill Tkhai <tkhai@yandex.ru>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140508225830.2469.97461.stgit@localhost
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-05-22 11:16:33 +02:00
Jason Low
52a08ef1f1 sched: Fix the rq->next_balance logic in rebalance_domains() and idle_balance()
Currently, in idle_balance(), we update rq->next_balance when we pull_tasks.
However, it is also important to update this in the !pulled_tasks case too.

When the CPU is "busy" (the CPU isn't idle), rq->next_balance gets computed
using sd->busy_factor (so we increase the balance interval when the CPU is
busy). However, when the CPU goes idle, rq->next_balance could still be set
to a large value that was computed with the sd->busy_factor.

Thus, we need to also update rq->next_balance in idle_balance() in the cases
where !pulled_tasks too, so that rq->next_balance gets updated without taking
the busy_factor into account when the CPU is about to go idle.

This patch makes rq->next_balance get updated independently of whether or
not we pulled_task. Also, we add logic to ensure that we always traverse
at least 1 of the sched domains to get a proper next_balance value for
updating rq->next_balance.

Additionally, since load_balance() modifies the sd->balance_interval, we
need to re-obtain the sched domain's interval after the call to
load_balance() in rebalance_domains() before we update rq->next_balance.

This patch adds and uses 2 new helper functions, update_next_balance() and
get_sd_balance_interval() to update next_balance and obtain the sched
domain's balance_interval.

Signed-off-by: Jason Low <jason.low2@hp.com>
Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: daniel.lezcano@linaro.org
Cc: alex.shi@linaro.org
Cc: efault@gmx.de
Cc: vincent.guittot@linaro.org
Cc: morten.rasmussen@arm.com
Cc: aswin@hp.com
Link: http://lkml.kernel.org/r/1399596562.2200.7.camel@j-VirtualBox
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-05-22 11:16:32 +02:00
Dongsheng Yang
a9467fa3cd sched: Use clamp() and clamp_val() to make sys_nice() more readable
Suggested-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1399541715-19568-1-git-send-email-yangds.fnst@cn.fujitsu.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-05-22 11:16:31 +02:00
Dietmar Eggemann
caffcdd8d2 sched: Do not zero sg->cpumask and sg->sgp->power in build_sched_groups()
There is no need to zero struct sched_group member cpumask and struct
sched_group_power member power since both structures are already allocated
as zeroed memory in __sdt_alloc().

This patch has been tested with
BUG_ON(!cpumask_empty(sched_group_cpus(sg))); and BUG_ON(sg->sgp->power);
in build_sched_groups() on ARM TC2 and INTEL i5 M520 platform including
CPU hotplug scenarios.

Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1398865178-12577-1-git-send-email-dietmar.eggemann@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-05-22 11:16:30 +02:00
Vincent Guittot
c515db8cd3 sched/numa: Fix initialization of sched_domain_topology for NUMA
Jet Chen has reported a kernel panics when booting qemu-system-x86_64 with
kvm64 cpu. A panic occured while building the sched_domain.

In sched_init_numa, we create a new topology table in which both default
levels and numa levels are copied. The last row of the table must have a null
pointer in the mask field.

The current implementation doesn't add this last row in the computation of the
table size. So we add 1 row in the allocation size that will be used as the
last row of the table. The kzalloc will ensure that the mask field is NULL.

Reported-by: Jet Chen <jet.chen@intel.com>
Tested-by: Jet Chen <jet.chen@intel.com>
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: fengguang.wu@intel.com
Link: http://lkml.kernel.org/r/1399972261-25693-1-git-send-email-vincent.guittot@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-05-22 11:16:29 +02:00
Rik van Riel
8bf21433f3 sched: Call select_idle_sibling() when not affine_sd
On smaller systems, the top level sched domain will be an affine
domain, and select_idle_sibling is invoked for every SD_WAKE_AFFINE
wakeup. This seems to be working well.

On larger systems, with the node distance between far away NUMA nodes
being > RECLAIM_DISTANCE, select_idle_sibling is only called if the
waker and the wakee are on nodes less than RECLAIM_DISTANCE apart.

This patch leaves in place the policy of not pulling the task across
nodes on such systems, while fixing the issue that select_idle_sibling
is not called at all in certain circumstances.

The code will look for an idle CPU in the same CPU package as the
CPU where the task ran previously.

Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: morten.rasmussen@arm.com
Cc: george.mccollister@gmail.com
Cc: ktkhai@parallels.com
Cc: Mel Gorman <mgorman@suse.de>
Cc: Mike Galbraith <umgwanakikbuti@gmail.com>
Link: http://lkml.kernel.org/r/20140514114037.2d93266f@annuminas.surriel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-05-22 11:16:28 +02:00
Michael Kerrisk
2240067494 sched: Simplify return logic in sched_read_attr()
Gotos are chained pointlessly here, and the 'out' label
can be dispensed with.

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/536CEC29.9090503@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-05-22 11:16:27 +02:00
Michael Kerrisk
e78c7bca56 sched: Simplify return logic in sched_copy_attr()
The logic in this function is a little contorted, clean it up:

  * Rather than having chained gotos for the -EFBIG case, just
    return -EFBIG directly.

  * Now, the label 'out' is no longer needed, and 'ret' must be zero
    zero by the time we fall through to this point, so just return 0.

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/536CEC24.9080201@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-05-22 11:16:26 +02:00