aoe: use high-resolution RTTs with fallback to low-res
authorEd Cashin <ecashin@coraid.com>
Tue, 18 Dec 2012 00:03:49 +0000 (16:03 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Tue, 18 Dec 2012 01:15:24 +0000 (17:15 -0800)
commit5f0c9c48e7265039c3f945aaf44a1c6ae8adbd01
tree2eb73358dc9ad58dce32dd40ceb0fbc938d915d4
parent0d555ecfa468f6dc29697829844f2f79909e376f
aoe: use high-resolution RTTs with fallback to low-res

These changes improve the accuracy of the decision about whether it's time
to retransmit an AoE command by using the microsecond-resolution
gettimeofday instead of jiffies.

Because the system time can jump suddenly, the decision reverts to using
jiffies if the high-resolution time difference is relatively large.
Otherwise the AoE targets could be considered failed inappropriately.

Signed-off-by: Ed Cashin <ecashin@coraid.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/block/aoe/aoe.h
drivers/block/aoe/aoecmd.c