Re: PROBLEM: Silent data corruption when using sendfile()

On Sat, 2012-07-14 at 12:13 +0200, Johannes Truschnigg wrote:

On Sat, Jul 14, 2012 at 10:31:36AM +0200, Willy Tarreau wrote:

quoted

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Please Johannes could you try latest kernel tree ?

It would be useful, especially given the amount of changes you performed
in this area in latest version, it could be very possible that this new
bug got fixed as a side effect !

I upgraded to 3.4.4 (identical config as the 3.4.0 build I've been running)
and what can I say - the problem really seems to have disappeared. I performed
about 3700 iterations of my previos tests over the night, and the data always
turned out to be OK, not a single byte turned out kaput!

I wish I would have tested that earlier, and spared you the noise... well,
maybe someone who runs into a similar problem in the future will have this
discovery save her/him some time and headaches and make her/him just upgrade
kernels :)

Thanks a lot for your polite and quick responses!

Nice to hear. Now we should make sure we have all needed fixes for prior
stable kernels as well !

Still trying to understand the issue, since I thought I only did
optimizations, not bug fixes. So maybe real bug is still there but its
probability of occurrence lowered enough to not hit your workload.
 
Hmmm...