Linus Torvalds 9226b5b440 vfs: avoid non-forwarding large load after small store in path lookup ... The performance regression that Josef Bacik reported in the pathname lookup (see commit 99d263d4c5 "vfs: fix bad hashing of dentries") made me look at performance stability of the dcache code, just to verify that the problem was actually fixed. That turned up a few other problems in this area. There are a few cases where we exit RCU lookup mode and go to the slow serializing case when we shouldn't, Al has fixed those and they'll come in with the next VFS pull. But my performance verification also shows that link_path_walk() turns out to have a very unfortunate 32-bit store of the length and hash of the name we look up, followed by a 64-bit read of the combined hash_len field. That screws up the processor store to load forwarding, causing an unnecessary hickup in this critical routine. It's caused by the ugly calling convention for the "hash_name()" function, and easily fixed by just making hash_name() fill in the whole 'struct qstr' rather than passing it a pointer to just the hash value. With that, the profile for this function looks much smoother. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2014-09-14 17:28:32 -07:00
..
acpi	ACPI / scan: not cache _SUN value in struct acpi_device_pnp	2014-09-03 22:41:14 +02:00
asm-generic	This is the bulk of GPIO changes for the v3.17 development	2014-08-08 18:00:35 -07:00
clocksource
crypto	Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security	2014-08-06 08:06:39 -07:00
drm	drm/radeon: add additional SI pci ids	2014-08-22 10:47:59 -04:00
dt-bindings	Merge branch 'for-linus' of git://git.infradead.org/users/vkoul/slave-dma	2014-08-11 07:14:01 -07:00
keys
kvm
linux	vfs: avoid non-forwarding large load after small store in path lookup	2014-09-14 17:28:32 -07:00
math-emu
media
memory
misc
net	Merge tag 'master-2014-09-04' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless	2014-09-07 16:11:10 -07:00
pcmcia
ras
rdma	Merge branches 'core', 'cxgb4', 'ipoib', 'iser', 'iwcm', 'mad', 'misc', 'mlx4', 'mlx5', 'ocrdma' and 'srp' into for-next	2014-08-14 08:58:04 -07:00
rxrpc
scsi	SCSI misc on 20140815	2014-08-15 18:28:58 -06:00
soc/tegra
sound	ASoC: core: fix .info for SND_SOC_BYTES_TLV	2014-08-18 08:59:12 -05:00
target
trace	net: treewide: Fix typo found in DocBook/networking.xml	2014-09-05 17:35:28 -07:00
uapi	USB fixes for 3.17-rc5	2014-09-12 11:59:10 -07:00
video	fbdev changes for 3.17	2014-08-08 18:09:33 -07:00
xen	xen/arm: introduce XENFEAT_grant_map_identity	2014-09-11 18:11:52 +00:00
Kbuild