linux/drivers
Nick Piggin fa0d7e3de6 fs: icache RCU free inodes
RCU free the struct inode. This will allow:

- Subsequent store-free path walking patch. The inode must be consulted for
  permissions when walking, so an RCU inode reference is a must.
- sb_inode_list_lock to be moved inside i_lock because sb list walkers who want
  to take i_lock no longer need to take sb_inode_list_lock to walk the list in
  the first place. This will simplify and optimize locking.
- Could remove some nested trylock loops in dcache code
- Could potentially simplify things a bit in VM land. Do not need to take the
  page lock to follow page->mapping.

The downsides of this is the performance cost of using RCU. In a simple
creat/unlink microbenchmark, performance drops by about 10% due to inability to
reuse cache-hot slab objects. As iterations increase and RCU freeing starts
kicking over, this increases to about 20%.

In cases where inode lifetimes are longer (ie. many inodes may be allocated
during the average life span of a single inode), a lot of this cache reuse is
not applicable, so the regression caused by this patch is smaller.

The cache-hot regression could largely be avoided by using SLAB_DESTROY_BY_RCU,
however this adds some complexity to list walking and store-free path walking,
so I prefer to implement this at a later date, if it is shown to be a win in
real situations. I haven't found a regression in any non-micro benchmark so I
doubt it will be a problem.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:26 +11:00
..
accessibility
acpi Merge branches 'bugzilla-25412' and 'bugzilla-25302' into release 2010-12-26 17:05:07 -05:00
amba
ata pata_cs5536: avoid implicit MSR API inclusion on x86-64 2010-12-26 19:42:15 -05:00
atm drivers/atm/atmtcp.c: add missing atm_dev_put 2010-12-31 12:52:05 -08:00
auxdisplay
base PM: Allow devices to be removed during late suspend and early resume 2010-11-11 01:50:53 +01:00
block Fix build error in drivers/block/cciss.c 2010-12-20 21:21:49 -08:00
bluetooth Bluetooth: add NULL pointer check in HCI 2010-12-08 13:22:22 -02:00
cdrom
char RAMOOPS: Don't overflow over non-allocated regions 2010-12-28 11:12:32 -08:00
clocksource clocksource: sh_cmt: Remove nested spinlock fix 2010-12-17 19:38:33 +09:00
connector connector: add module alias 2010-12-10 12:27:49 -08:00
cpufreq
cpuidle
crypto Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2010-11-13 09:55:56 -08:00
dca
dio
dma Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx 2011-01-03 11:48:54 -08:00
edac amd64_edac: Fix interleaving check 2010-12-08 19:52:54 +01:00
eisa
firewire firewire: ohci: fix regression with Agere FW643 rev 06, disable MSI 2010-12-12 15:47:02 +01:00
firmware
gpio cs5535-gpio: handle GPIO regs where higher (clear) bits are set 2010-12-23 15:31:48 -08:00
gpu drm/i915/dvo: Report LVDS attached to ch701x as connected 2010-12-30 13:50:43 +00:00
hid Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid 2010-12-02 17:40:04 -08:00
hwmon hwmon: (s3c-hwmon) Fix compilation 2011-01-02 15:31:11 -08:00
i2c i2c_intel_mid: Fix slash in sysfs name 2010-12-14 18:46:01 -08:00
ide
idle intel_idle: recognize ARAT on WSM-EX 2010-12-02 01:19:32 -05:00
ieee802154
infiniband fs: dcache rationalise dget variants 2011-01-07 17:50:24 +11:00
input Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input 2010-12-16 08:33:44 -08:00
isdn ISDN, Gigaset: Fix memory leak in do_disconnect_req() 2010-12-31 11:17:10 -08:00
leds led_class: fix typo in blink API 2010-12-22 19:43:34 -08:00
lguest
macintosh leds: fix up dependencies 2010-12-02 14:51:15 -08:00
mca
md Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block 2010-12-20 09:19:46 -08:00
media [media] em28xx: radio_fops should also use unlocked_ioctl 2011-01-03 09:52:25 -02:00
memstick
message SCSI host lock push-down 2010-11-16 13:33:23 -08:00
mfd mfd: Support additional parent IDs for wm831x 2010-12-22 12:05:22 +01:00
misc drivers/misc/isl29020.c: remove incorrect kfree in isl29020_remove() 2010-11-25 06:50:47 +09:00
mmc mmc: Fix re-probing with PM_POST_RESTORE notification 2010-12-21 11:46:49 -08:00
mtd Merge branch 'omap-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap-2.6 2010-12-14 17:36:35 -08:00
net atl1: fix oops when changing tx/rx ring params 2011-01-03 11:04:49 -08:00
nubus
of of/i2c: Fix request module by alias 2010-12-24 01:28:54 -07:00
oprofile Merge branches 'perf-fixes-for-linus' and 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-10-30 11:43:26 -07:00
parisc parisc: KittyHawk LCD fix 2010-12-04 11:18:25 -05:00
parport
pci PCI hotplug: Fix unexpected driver unregister in pciehp_acpi.c 2010-12-23 12:51:49 -08:00
pcmcia ARM: 6456/1: Fix for building DEBUG with sa11xx_base.c as a module. 2010-12-04 12:47:48 +00:00
platform drm/i915, intel_ips: When i915 loads after IPS, make IPS relink to i915. 2010-12-23 09:51:36 +00:00
pnp ACPI/PNP: avoid section mismatch warning 2010-12-11 02:01:47 -05:00
power
pps
ps3
rapidio rapidio: use resource_size() 2010-11-12 07:55:30 -08:00
regulator regulator: tps6586x: correct register table 2010-12-09 09:23:43 +00:00
rtc rtc: rs5c372: fix buffer size 2010-12-22 19:43:34 -08:00
s390 [SCSI] zfcp: Issue FCP command without holding SCSI host_lock 2010-12-09 09:41:23 -06:00
sbus
scsi Merge git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-rc-fixes-2.6 2010-12-24 12:58:43 -08:00
serial Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb 2010-12-14 14:35:04 -08:00
sfi
sh sh: intc: Initialize radix tree gfp mask explicitly. 2010-12-24 19:38:37 +09:00
sn
spi spi/m68knommu: Coldfire QSPI platform support 2010-12-29 23:28:25 -07:00
ssb ssb: b43-pci-bridge: Add new vendor for BCM4318 2010-11-22 15:19:31 -05:00
staging fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
tc
telephony
thermal
tty n_gsm: gsm_data_alloc buffer allocation could fail and it is not being checked 2010-12-16 13:03:13 -08:00
uio uio: Change mail address of Hans J. Koch 2010-11-10 16:57:11 -08:00
usb fs: dcache remove dcache_lock 2011-01-07 17:50:23 +11:00
uwb UWB: Return UWB_RSV_ALLOC_NOT_FOUND rather than crashing on NULL dereference if kzalloc fails 2010-11-11 07:14:07 -08:00
vhost vhost: correctly set bits of dirty pages 2010-11-29 10:26:55 +02:00
video Merge branch 'fbdev-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/lethal/fbdev-2.6 2010-12-27 10:33:30 -08:00
virtio virtio: fix format of sysfs driver/vendor files 2010-11-24 15:21:12 +10:30
vlynq
w1
watchdog watchdog: Fix null pointer dereference while accessing rdc321x platform_data 2010-12-22 12:05:21 +01:00
xen Merge branch '2.6.37-rc4-pvhvm-fixes' of git://xenbits.xen.org/people/sstabellini/linux-pvhvm 2010-12-03 11:30:57 -08:00
zorro BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
Kconfig
Makefile TTY: create drivers/tty and move the tty core files there 2010-11-05 08:10:33 -07:00