linux/include
Nick Piggin 44a7d7a878 fs: cache optimise dentry and inode for rcu-walk
Put dentry and inode fields into top of data structure.  This allows RCU path
traversal to perform an RCU dentry lookup in a path walk by touching only the
first 56 bytes of the dentry.

We also fit in 8 bytes of inline name in the first 64 bytes, so for short
names, only 64 bytes needs to be touched to perform the lookup. We should
get rid of the hash->prev pointer from the first 64 bytes, and fit 16 bytes
of name in there, which will take care of 81% rather than 32% of the kernel
tree.

inode is also rearranged so that RCU lookup will only touch a single cacheline
in the inode, plus one in the i_ops structure.

This is important for directory component lookups in RCU path walking. In the
kernel source, directory names average is around 6 chars, so this works.

When we reach the last element of the lookup, we need to lock it and take its
refcount which requires another cacheline access.

Align dentry and inode operations structs, so members will be at predictable
offsets and we can group common operations into head of structure.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:28 +11:00
..
acpi ACPI: video: fix build for CONFIG_ACPI=n 2010-12-11 02:01:46 -05:00
asm-generic asm-generic/stat.h: support 64-bit file time_t for stat() 2010-11-01 15:31:29 -04:00
crypto Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2010-10-24 13:41:39 -07:00
drm drm/i915: announce to userspace that the bsd ring is coherent 2010-12-05 10:40:39 +00:00
keys
linux fs: cache optimise dentry and inode for rcu-walk 2011-01-07 17:50:28 +11:00
math-emu
media [media] wm8775: Revert changeset fcb9757333 to avoid a regression 2011-01-03 09:09:56 -02:00
mtd mtd: Define MLC Flash as a different flash type 2010-10-25 00:50:20 +01:00
net Revert "ipv4: Allow configuring subnets as local addresses" 2010-12-23 12:03:57 -08:00
pcmcia pcmcia: IOCARD is also required for using IRQs 2010-10-22 08:46:36 +02:00
rdma IB/core: Add VLAN support for IBoE 2010-10-25 10:20:39 -07:00
rxrpc
scsi SCSI host lock push-down 2010-11-16 13:33:23 -08:00
sound ARM: mach-shmobile: ap4evb: FSI clock use proper process for HDMI 2010-11-24 15:29:56 +09:00
trace ext4: Add new ext4 inode tracepoints 2010-11-08 13:51:33 -05:00
video fbdev: da8xx: punt duplicated FBIO_WAITFORVSYNC define 2010-11-16 10:14:22 +09:00
xen xen: Provide a variant of __RING_SIZE() that is an integer constant expression 2010-12-15 12:34:28 -08:00
Kbuild