Messages in this thread | | | Date | Sat, 11 Oct 2008 21:17:29 +0300 | From | Eduard - Gabriel Munteanu <> | Subject | Re: [PROBLEM] hard-lock with kmemtrace, relayfs, and splice |
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On Fri, Oct 10, 2008 at 11:58:51PM -0500, Tom Zanussi wrote: > It worked for me, but I also had to apply the following patch to > kmemtraced: > > diff --git a/kmemtraced.c b/kmemtraced.c > index 217478d..324ced9 100644 > --- a/kmemtraced.c > +++ b/kmemtraced.c > @@ -109,6 +109,8 @@ static void *reader_thread(void *data) > if (retval < 0) > panic("splice() (from) failed: %s\n", > strerror(errno)); > + if (!retval) > + continue; > retval = splice(pipe_fd[0], NULL, log_fd, NULL, > 128, SPLICE_F_MOVE); > if (retval < 0) > > Otherwise it would end up hanging kmemtraced in the second splice (pipe > to log_fd) if the return from the first splice was 0 (i.e. there's no > data available (and we can never know if there will ever be any > more)).
Thanks, I'll apply it.
> I'm not sure why kmemtraced is only splicing 128 bytes at a time - it > seems to defeat the purpose - or why it wouldn't be using poll to know > when there's at least a whole sub-buffer to splice, but to each his own. > Hopefully the kernel patch at least fixes the loop.
Yeah, it was a misguided attempt to fix the strange behavior.
> Tom
Cheers, Eduard
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