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0ee931c4e3
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Michal Hocko 0ee931c4e3 mm: treewide: remove GFP_TEMPORARY allocation flag 
GFP_TEMPORARY was introduced by commit e12ba74d8f ("Group short-lived
and reclaimable kernel allocations") along with __GFP_RECLAIMABLE.  It's
primary motivation was to allow users to tell that an allocation is
short lived and so the allocator can try to place such allocations close
together and prevent long term fragmentation.  As much as this sounds
like a reasonable semantic it becomes much less clear when to use the
highlevel GFP_TEMPORARY allocation flag.  How long is temporary? Can the
context holding that memory sleep? Can it take locks? It seems there is
no good answer for those questions.

The current implementation of GFP_TEMPORARY is basically GFP_KERNEL |
__GFP_RECLAIMABLE which in itself is tricky because basically none of
the existing caller provide a way to reclaim the allocated memory.  So
this is rather misleading and hard to evaluate for any benefits.

I have checked some random users and none of them has added the flag
with a specific justification.  I suspect most of them just copied from
other existing users and others just thought it might be a good idea to
use without any measuring.  This suggests that GFP_TEMPORARY just
motivates for cargo cult usage without any reasoning.

I believe that our gfp flags are quite complex already and especially
those with highlevel semantic should be clearly defined to prevent from
confusion and abuse.  Therefore I propose dropping GFP_TEMPORARY and
replace all existing users to simply use GFP_KERNEL.  Please note that
SLAB users with shrinkers will still get __GFP_RECLAIMABLE heuristic and
so they will be placed properly for memory fragmentation prevention.

I can see reasons we might want some gfp flag to reflect shorterm
allocations but I propose starting from a clear semantic definition and
only then add users with proper justification.

This was been brought up before LSF this year by Matthew [1] and it
turned out that GFP_TEMPORARY really doesn't have a clear semantic.  It
seems to be a heuristic without any measured advantage for most (if not
all) its current users.  The follow up discussion has revealed that
opinions on what might be temporary allocation differ a lot between
developers.  So rather than trying to tweak existing users into a
semantic which they haven't expected I propose to simply remove the flag
and start from scratch if we really need a semantic for short term
allocations.

[1] http://lkml.kernel.org/r/20170118054945.GD18349@bombadil.infradead.org

[akpm@linux-foundation.org: fix typo]
[akpm@linux-foundation.org: coding-style fixes]
[sfr@canb.auug.org.au: drm/i915: fix up]
  Link: http://lkml.kernel.org/r/20170816144703.378d4f4d@canb.auug.org.au
Link: http://lkml.kernel.org/r/20170728091904.14627-1-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Mel Gorman <mgorman@suse.de>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Neil Brown <neilb@suse.de>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-13 18:53:16 -07:00
..
842 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2016-03-17 21:38:27 -07:00
fonts lib/fonts/Kconfig: keep non-Sparc fonts listed together 2017-02-27 18:43:46 -08:00
lz4 lib/lz4: remove back-compat wrappers 2017-02-24 17:46:57 -08:00
lzo lzo: check for length overrun in variable length encoding. 2014-09-28 11:08:01 +02:00
mpi Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2017-08-22 14:53:32 +08:00
raid6 Merge tag 'md/4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md 2017-09-07 12:41:48 -07:00
reed_solomon
xz lib/xz: enable all filters by default in Kconfig 2014-06-04 16:54:18 -07:00
zlib_deflate zlib_deflate/deftree: remove bi_reverse() 2015-09-10 13:29:01 -07:00
zlib_inflate lib/zlib_inflate/inftrees.c: fix potential buffer overflow 2017-05-08 17:15:12 -07:00
.gitignore
argv_split.c
asn1_decoder.c Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2016-05-17 09:33:39 -07:00
assoc_array.c assoc_array: fix path to assoc_array documentation 2017-08-30 16:40:11 -06:00
atomic64_test.c lib/atomic64_test.c: add a test that atomic64_inc_not_zero() returns an int 2017-07-14 15:05:13 -07:00
atomic64.c locking/atomic: Implement atomic{,64,_long}_fetch_{add,sub,and,andnot,or,xor}{,_relaxed,_acquire,_release}() 2016-06-16 10:48:32 +02:00
audit.c syscalls: implement execveat() system call 2014-12-13 12:42:51 -08:00
bcd.c
bch.c
bitmap.c lib/bitmap.c: make bitmap_parselist() thread-safe and much faster 2017-09-08 18:26:49 -07:00
bitrev.c ARM: 8187/1: add CONFIG_HAVE_ARCH_BITREVERSE to support rbit instruction 2014-12-22 16:43:06 +00:00
bsearch.c lib/bsearch.c: micro-optimize pivot position calculation 2017-07-10 16:32:35 -07:00
btree.c treewide: Remove old email address 2015-11-23 09:44:58 +01:00
bug.c debug: Add _ONCE() logic to report_bug() 2017-03-30 09:37:20 +02:00
build_OID_registry
bust_spinlocks.c
chacha20.c random: replace non-blocking pool with a Chacha20-based CRNG 2016-07-03 00:57:23 -04:00
check_signature.c
checksum.c ipv4: Update parameters for csum_tcpudp_magic to their original types 2016-03-13 23:55:13 -04:00
clz_ctz.c
clz_tab.c
cmdline.c lib/cmdline.c: remove meaningless comment 2017-09-08 18:26:49 -07:00
compat_audit.c
cordic.c
cpu_rmap.c sched/topology: Rename topology_thread_cpumask() to topology_sibling_cpumask() 2015-05-27 15:22:15 +02:00
cpumask.c cpumask: make cpumask_next() out-of-line 2017-09-08 18:26:51 -07:00
crc4.c lib: Add crc4 module 2017-06-09 11:52:07 +02:00
crc7.c
crc8.c
crc16.c
crc32.c lib: add module support to crc32 tests 2017-02-24 17:46:57 -08:00
crc32defs.h
crc32test.c lib: add module support to crc32 tests 2017-02-24 17:46:57 -08:00
crc-ccitt.c
crc-itu-t.c lib: crc-itu-t.[ch] fix 0x0x prefix in integer constants 2015-05-26 15:26:43 +02:00
crc-t10dif.c lib: introduce crc_t10dif_update() 2015-05-30 22:42:24 -07:00
ctype.c
debug_info.c kbuild: include core debug info when DEBUG_INFO_REDUCED 2015-06-11 15:08:32 +02:00
debug_locks.c
debugobjects.c debugobjects: Make kmemleak ignore debug objects 2017-08-14 16:51:01 +02:00
dec_and_lock.c
decompress_bunzip2.c lib/decompressors: use real out buf size for gunzip with kernel 2015-09-10 13:29:01 -07:00
decompress_inflate.c lib/decompressors: use real out buf size for gunzip with kernel 2015-09-10 13:29:01 -07:00
decompress_unlz4.c lib/decompress_unlz4: change module to work with new LZ4 module version 2017-02-24 17:46:57 -08:00
decompress_unlzma.c lib/decompress_unlzma: Do a NULL check for pointer 2015-09-10 13:29:01 -07:00
decompress_unlzo.c lib/decompressors: use real out buf size for gunzip with kernel 2015-09-10 13:29:01 -07:00
decompress_unxz.c lib/decompressors: use real out buf size for gunzip with kernel 2015-09-10 13:29:01 -07:00
decompress.c lib/decompress: set the compressor name to NULL on error 2015-07-17 16:39:54 -07:00
devres.c devres: fix devm_ioremap_*() offset parameter kerneldoc description 2017-04-24 13:53:13 -05:00
digsig.c KEYS: Differentiate uses of rcu_dereference_key() and user_key_payload() 2017-03-02 10:09:00 +11:00
div64.c __div64_32(): make it overridable at compile time 2015-11-16 14:42:12 -05:00
dma-debug.c dmaengine updates for 4.12-rc1 2017-05-09 15:40:28 -07:00
dma-noop.c dma: Take into account dma_pfn_offset 2017-06-28 06:55:01 -07:00
dma-virt.c dma-virt: remove dma_supported and mapping_error methods 2017-06-28 06:54:41 -07:00
dump_stack.c sched/headers: Prepare for new header dependencies before moving code to <linux/sched/debug.h> 2017-03-02 08:42:34 +01:00
dynamic_debug.c dynamic_debug: add jump label support 2016-08-04 08:50:07 -04:00
dynamic_queue_limits.c lib/dynamic_queue_limits.c: simplify includes 2015-02-12 18:54:15 -08:00
earlycpio.c lib/cpio: Make find_cpio_data()'s offset arg optional 2016-06-08 11:04:19 +02:00
errseq.c errseq: rename __errseq_set to errseq_set 2017-07-26 12:24:36 -04:00
extable.c lib/extable.c: use bsearch() library function in search_extable() 2017-07-10 16:32:35 -07:00
fault-inject.c fault-inject: fix wrong should_fail() decision in task context 2017-08-10 15:54:06 -07:00
fdt_empty_tree.c
fdt_ro.c
fdt_rw.c
fdt_strerror.c
fdt_sw.c
fdt_wip.c
fdt.c
find_bit.c lib/find_bit.c: micro-optimise find_next_*_bit 2017-02-24 17:46:57 -08:00
flex_array.c
flex_proportions.c percpu_counter: Rename __percpu_counter_add to percpu_counter_add_batch 2017-06-20 15:42:32 -04:00
gcd.c lib/GCD.c: use binary GCD algorithm instead of Euclidean 2016-05-20 17:58:30 -07:00
gen_crc32table.c lib: crc32: constify crc32 lookup table 2015-02-13 21:21:35 -08:00
genalloc.c lib/genalloc.c: start search from start of chunk 2016-10-27 18:43:43 -07:00
glob.c lib: add module support to glob tests 2017-02-24 17:46:57 -08:00
globtest.c lib: add module support to glob tests 2017-02-24 17:46:57 -08:00
hexdump.c lib/hexdump.c: return -EINVAL in case of error in hex2bin() 2017-09-08 18:26:49 -07:00
hweight.c x86/hweight: Get rid of the special calling convention 2016-06-08 15:01:02 +02:00
idr.c idr: remove WARN_ON_ONCE() when trying to replace negative ID 2017-09-13 18:53:15 -07:00
inflate.c
int_sqrt.c
interval_tree_test.c lib/interval_tree: fast overlap detection 2017-09-08 18:26:49 -07:00
interval_tree.c lib/interval_tree.c: simplify includes 2015-02-12 18:54:15 -08:00
iomap_copy.c lib/iomap_copy.c: add __ioread32_copy() 2016-01-20 17:09:18 -08:00
iomap.c
iommu-common.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc 2015-11-05 16:34:48 -08:00
iommu-helper.c lib/iommu-helper: skip to next segment 2016-08-02 19:35:07 -04:00
ioremap.c mm: convert generic code to 5-level paging 2017-03-09 11:48:47 -08:00
iov_iter.c Merge branch 'uaccess-work.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-07 20:39:20 -07:00
irq_poll.c This adds a new gcc plugin named "latent_entropy". It is designed to 2016-10-15 10:03:15 -07:00
irq_regs.c
is_single_threaded.c sched/headers: Prepare to move 'init_task' and 'init_thread_union' from <linux/sched.h> to <linux/sched/task.h> 2017-03-02 08:42:38 +01:00
jedec_ddr_data.c
kasprintf.c lib/kasprintf.c: add sanity check to kvasprintf 2016-01-16 11:17:27 -08:00
Kconfig libnvdimm for 4.14 2017-09-11 13:10:57 -07:00
Kconfig.debug lib: add test module for CONFIG_DEBUG_VIRTUAL 2017-09-08 18:26:49 -07:00
Kconfig.kasan mm, kasan: switch SLUB to stackdepot, enable memory quarantine for SLUB 2016-07-28 16:07:41 -07:00
Kconfig.kgdb lib: update location of kgdb documentation 2017-05-16 08:44:22 -03:00
Kconfig.kmemcheck
Kconfig.ubsan Kconfig: lib/Kconfig.ubsan fix reference to ubsan documentation 2016-12-14 16:04:08 -08:00
kfifo.c kfifo: use BUG_ON 2014-08-08 15:57:25 -07:00
klist.c klist: fix starting point removed bug in klist iterators 2016-02-07 22:18:47 -08:00
kobject_uevent.c Merge branch 'bind_unbind' into driver-core-next 2017-07-22 12:00:15 +02:00
kobject.c kobject: Export kobject_get_unless_zero() 2017-03-22 20:11:35 -06:00
kstrtox.c lib/kstrtox.c: use "unsigned int" more 2017-07-10 16:32:34 -07:00
kstrtox.h
lcm.c block: fix blk_stack_limits() regression due to lcm() change 2015-03-31 09:45:50 -06:00
libcrc32c.c crypto: Work around deallocated stack frame reference gcc bug on sparc. 2017-06-08 17:36:03 +08:00
list_debug.c bug: switch data corruption check to __must_check 2017-02-24 17:46:56 -08:00
list_sort.c lib: add module support to linked list sorting tests 2017-05-08 17:15:10 -07:00
llist.c lib/llist.c: fix data race in llist_del_first 2015-11-06 17:50:42 -08:00
locking-selftest-hardirq.h
locking-selftest-mutex.h
locking-selftest-rlock-hardirq.h
locking-selftest-rlock-softirq.h
locking-selftest-rlock.h
locking-selftest-rsem.h
locking-selftest-rtmutex.h locking/selftest: Add RT-mutex support 2017-06-08 10:35:50 +02:00
locking-selftest-softirq.h
locking-selftest-spin-hardirq.h
locking-selftest-spin-softirq.h
locking-selftest-spin.h
locking-selftest-wlock-hardirq.h
locking-selftest-wlock-softirq.h
locking-selftest-wlock.h
locking-selftest-wsem.h
locking-selftest.c locking/lockdep/selftests: Fix mixed read-write ABBA tests 2017-08-29 15:15:17 +02:00
lockref.c locking/core: Remove cpu_relax_lowlatency() users 2016-11-16 10:15:10 +01:00
lru_cache.c lru_cache: Converted lc_seq_printf_status to return void 2015-11-25 09:22:02 -07:00
Makefile lib: add test module for CONFIG_DEBUG_VIRTUAL 2017-09-08 18:26:49 -07:00
memory-notifier-error-inject.c
memweight.c
net_utils.c mac_pton: Use bool not int return 2014-06-25 17:45:43 -07:00
netdev-notifier-error-inject.c net: Add support for CHANGEUPPER notifier error injection 2015-12-03 11:49:23 -05:00
nlattr.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next 2017-09-03 17:08:42 -07:00
nmi_backtrace.c printk: Use the main logbuf in NMI when logbuf_lock is available 2017-05-19 14:42:19 +02:00
nodemask.c include/linux/nodemask.h: create next_node_in() helper 2016-05-19 19:12:14 -07:00
notifier-error-inject.c
notifier-error-inject.h
of-reconfig-notifier-error-inject.c
oid_registry.c lib/oid_registry.c: X.509: fix the buffer overflow in the utility function for OID string 2017-09-08 18:26:49 -07:00
once.c once: make helper generic for calling functions once 2015-10-08 05:26:36 -07:00
parman.c lib: Introduce priority array area manager 2017-02-03 16:35:42 -05:00
parser.c parser: add u64 number parser 2016-12-06 10:17:03 +02:00
pci_iomap.c libnvdimm for 4.3: 2015-09-08 14:35:59 -07:00
percpu_counter.c writeback: rework wb_[dec|inc]_stat family of functions 2017-07-12 16:26:05 -07:00
percpu_ida.c sched/headers: Prepare to remove the <linux/gfp.h> include from <linux/sched.h> 2017-03-02 08:42:34 +01:00
percpu_test.c
percpu-refcount.c percpu-refcount: support synchronous switch to atomic mode. 2017-03-22 19:18:43 -07:00
plist.c sched/headers: Prepare for new header dependencies before moving code to <linux/sched/clock.h> 2017-03-02 08:42:27 +01:00
pm-notifier-error-inject.c
prime_numbers.c lib/prime_numbers: Suppress warn on kmalloc failure 2017-01-23 09:17:12 +01:00
radix-tree.c radix-tree: must check __radix_tree_preload() return value 2017-09-08 18:26:49 -07:00
random32.c This adds a new gcc plugin named "latent_entropy". It is designed to 2016-10-15 10:03:15 -07:00
ratelimit.c ratelimit: extend to print suppressed messages on release 2016-08-02 19:35:06 -04:00
rational.c
rbtree_test.c lib/rbtree_test.c: support rb_root_cached 2017-09-08 18:26:48 -07:00
rbtree.c rbtree: add some additional comments for rebalancing cases 2017-09-08 18:26:48 -07:00
reciprocal_div.c
refcount.c locking/refcount: Create unchecked atomic_t implementation 2017-06-28 18:54:46 +02:00
rhashtable.c Add wait_for_random_bytes() and get_random_*_wait() functions so that 2017-07-15 12:44:02 -07:00
sbitmap.c sbitmap: add sbitmap_get_shallow() operation 2017-04-14 14:06:52 -06:00
scatterlist.c scatterlist: add sg_zero_buffer() helper 2017-06-15 14:30:14 +02:00
seq_buf.c tracing: Use seq_buf_used() in seq_buf_to_user() instead of len 2015-12-23 14:27:20 -05:00
sg_pool.c lib: scatterlist: move SG pool code from SCSI driver to lib/sg_pool.c 2016-04-15 16:53:14 -04:00
sg_split.c lib: scatterlist: add sg splitting function 2015-08-24 14:28:01 -06:00
sha1.c lib: EXPORT_SYMBOL sha_init 2015-03-23 22:12:08 -04:00
show_mem.c lib/show_mem.c: teach show_mem to work with the given nodemask 2017-02-22 16:41:30 -08:00
siphash.c siphash: implement HalfSipHash1-3 for hash tables 2017-01-09 13:58:57 -05:00
smp_processor_id.c sched/core: Enable might_sleep() and smp_processor_id() checks early 2017-05-23 10:01:38 +02:00
sort.c lib: add CONFIG_TEST_SORT to enable self-test of sort() 2017-02-24 17:46:57 -08:00
stackdepot.c lib/stackdepot: export save/fetch stack for drivers 2016-11-11 08:12:37 -08:00
stmp_device.c lib/stmp_device.c: replace module.h include 2015-02-12 18:54:16 -08:00
string_helpers.c mm: treewide: remove GFP_TEMPORARY allocation flag 2017-09-13 18:53:16 -07:00
string.c lib/string.c: check for kmalloc() failure 2017-09-08 18:26:49 -07:00
strncpy_from_user.c lib: harden strncpy_from_user 2016-10-11 15:06:30 -07:00
strnlen_user.c kill strlen_user() 2017-05-15 23:40:22 -04:00
swiotlb.c swiotlb: Add warnings for use of bounce buffers with SME 2017-07-18 11:38:03 +02:00
syscall.c lib/syscall: Clear return values when no stack 2017-03-24 07:43:35 +01:00
test_bitmap.c lib/test_bitmap.c: use ULL suffix for 64-bit constants 2017-09-13 18:53:15 -07:00
test_bpf.c bpf: add BPF_J{LT,LE,SLT,SLE} instructions 2017-08-09 16:53:56 -07:00
test_debug_virtual.c lib: add test module for CONFIG_DEBUG_VIRTUAL 2017-09-08 18:26:49 -07:00
test_firmware.c test_firmware: add batched firmware tests 2017-08-10 13:58:41 -07:00
test_hash.c lib/test_hash.c: fix warning in preprocessor symbol evaluation 2016-09-01 17:52:01 -07:00
test_hexdump.c test_hexdump: print statistics at the end 2016-01-20 17:09:18 -08:00
test_kasan.c kasan: report only the first error by default 2017-03-31 17:13:30 -07:00
test_kmod.c test_kmod: flip INT checks to be consistent 2017-09-08 18:26:50 -07:00
test_list_sort.c lib: add module support to linked list sorting tests 2017-05-08 17:15:10 -07:00
test_module.c
test_parman.c lib: fix spelling mistake: "actualy" -> "actually" 2017-02-26 11:03:38 -05:00
test_printf.c mm, printk: introduce new format string for flags 2016-03-15 16:55:16 -07:00
test_rhashtable.c lib: test_rhashtable: Fix KASAN warning 2017-07-25 12:35:23 -07:00
test_siphash.c siphash: implement HalfSipHash1-3 for hash tables 2017-01-09 13:58:57 -05:00
test_sort.c Revert "lib/test_sort.c: make it explicitly non-modular" 2017-05-08 17:15:10 -07:00
test_static_key_base.c locking/static_keys: Provide a selftest 2015-08-03 11:51:12 +02:00
test_static_keys.c locking/static_keys: Avoid nested functions 2016-02-09 10:27:29 +01:00
test_sysctl.c test_sysctl: test against int proc_dointvec() array support 2017-07-12 16:26:00 -07:00
test_user_copy.c lib: remove check for AVR32 arch in test_user_copy 2017-05-01 09:36:30 +02:00
test_uuid.c uuid: fix incorrect uuid_equal conversion in test_uuid_test 2017-07-21 09:38:30 +02:00
test-kstrtox.c kstrto*: accept "-0" for signed conversion 2015-09-10 13:29:01 -07:00
test-string_helpers.c lib/test-string_helpers.c: fix and improve string_get_size() tests 2016-02-03 08:28:43 -08:00
textsearch.c lib/textsearch.c: remove textsearch_put reference from comments 2014-10-14 02:18:14 +02:00
timerqueue.c timerqueue: Use rb_entry_safe() instead of open-coding it 2017-01-20 08:03:42 +01:00
ts_bm.c
ts_fsm.c
ts_kmp.c
ubsan.c UBSAN: fix typo in format string 2016-08-02 17:31:41 -04:00
ubsan.h UBSAN: run-time undefined behavior sanity checker 2016-01-20 17:09:18 -08:00
ucs2_string.c lib/ucs2_string: Speed up ucs2_utf8size() 2016-09-09 16:08:46 +01:00
usercopy.c copy_{from,to}_user(): move kasan checks and might_fault() out-of-line 2017-06-29 22:21:20 -04:00
uuid.c uuid: hoist uuid_is_null() helper from libnvdimm 2017-06-05 16:59:05 +02:00
vsprintf.c DeviceTree for 4.13: 2017-07-07 10:37:54 -07:00
win_minmax.c lib/win_minmax: windowed min or max estimator 2016-09-21 00:22:59 -04:00