kernel-fxtec-pro1x/include
Eric Dumazet 404e0a8b6a net: ipv4: fix RCU races on dst refcounts
commit c6cffba4ff (ipv4: Fix input route performance regression.)
added various fatal races with dst refcounts.

crashes happen on tcp workloads if routes are added/deleted at the same
time.

The dst_free() calls from free_fib_info_rcu() are clearly racy.

We need instead regular dst refcounting (dst_release()) and make
sure dst_release() is aware of RCU grace periods :

Add DST_RCU_FREE flag so that dst_release() respects an RCU grace period
before dst destruction for cached dst

Introduce a new inet_sk_rx_dst_set() helper, using atomic_inc_not_zero()
to make sure we dont increase a zero refcount (On a dst currently
waiting an rcu grace period before destruction)

rt_cache_route() must take a reference on the new cached route, and
release it if was not able to install it.

With this patch, my machines survive various benchmarks.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-30 14:53:22 -07:00
..
acpi Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux 2012-07-26 14:28:55 -07:00
asm-generic Merge branch 'for-linus' of git://git.linaro.org/people/rmk/linux-arm 2012-07-27 15:14:26 -07:00
crypto
drm Merge branch 'drm-nouveau-fixes' of git://anongit.freedesktop.org/git/nouveau/linux-2.6 into drm-next 2012-07-26 10:35:44 +10:00
keys
linux Merge branch 'for-linus' of git://git.linaro.org/people/rmk/linux-arm 2012-07-27 15:14:26 -07:00
math-emu
media
memory
misc
mtd
net net: ipv4: fix RCU races on dst refcounts 2012-07-30 14:53:22 -07:00
pcmcia
rdma Merge branches 'cma', 'cxgb4', 'misc', 'mlx4-sriov', 'mlx-cleanups', 'ocrdma' and 'qib' into for-linus 2012-07-22 23:26:17 -07:00
rxrpc
scsi Merge branch 'master' [vanilla Linus master] into libata-dev.git/upstream 2012-07-25 15:58:48 -04:00
sound Merge branch 'topic/pm-convert' into for-next 2012-07-19 08:21:57 +02:00
target target: Allow for target_submit_cmd() returning errors 2012-07-17 17:05:05 -07:00
trace Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-07-26 13:17:17 -07:00
video
xen xen PVonHVM: move shared_info to MMIO before kexec 2012-07-19 15:52:05 -04:00
Kbuild