android_kernel_xiaomi_sm8350/include
Eric Dumazet 5635c10d97 net: make sure struct dst_entry refcount is aligned on 64 bytes
As found in the past (commit f1dd9c379c
[NET]: Fix tbench regression in 2.6.25-rc1), it is really
important that struct dst_entry refcount is aligned on a cache line.

We cannot use __atribute((aligned)), so manually pad the structure
for 32 and 64 bit arches.

for 32bit : offsetof(truct dst_entry, __refcnt) is 0x80
for 64bit : offsetof(truct dst_entry, __refcnt) is 0xc0

As it is not possible to guess at compile time cache line size,
we use a generic value of 64 bytes, that satisfies many current arches.
(Using 128 bytes alignment on 64bit arches would waste 64 bytes)

Add a BUILD_BUG_ON to catch future updates to "struct dst_entry" dont
break this alignment.

"tbench 8" is 4.4 % faster on a dual quad core (HP BL460c G1), Intel E5450 @3.00GHz
(2350 MB/s instead of 2250 MB/s)

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-16 19:46:36 -08:00
..
acpi
asm-arm
asm-frv
asm-generic Fix __pfn_to_page(pfn) for CONFIG_DISCONTIGMEM=y 2008-11-08 10:02:48 -08:00
asm-h8300
asm-m32r
asm-m68k
asm-mn10300
asm-x86 x86: add iomap_atomic*()/iounmap_atomic() on 32-bit using fixmaps 2008-10-31 10:12:38 +01:00
asm-xtensa
crypto
drm drm/i915: Filter pci devices based on PCI_CLASS_DISPLAY_VGA 2008-11-11 18:02:12 +10:00
keys
linux udp: Use hlist_nulls in UDP RCU code 2008-11-16 19:39:21 -08:00
math-emu
media
mtd
net net: make sure struct dst_entry refcount is aligned on 64 bytes 2008-11-16 19:46:36 -08:00
pcmcia
rdma
rxrpc
scsi
sound Merge branches 'topic/fix/misc' and 'topic/fix/hda' into for-linus 2008-11-10 17:58:46 +01:00
trace
video
xen
Kbuild