Hi Andrew,
Sorry I have been a bit slow on this.
On Tue, 23 Apr 2002 09:58:14 -0700 Andrew Burgess <aab@cichlid.com> wrote:
>
> I am seeing something very strange with the dnotify feature in kernel
> 2.4.19pre6aa1. I'm developing a file copy daemon that makes backups of
> files as soon as they change so I run dnotify on every directory in my
> system (essentially). I based my program on the example in dnotify.txt
> in the Documentation directory.
So far, so good :-)
> I notice that after a while two things happen:
>
> 1) In my copyd process I start getting signals for directories that are
> not changing. Even stranger, I get signals for fd that I've never
> opened.
OK, this is weird, but I am looking into it.
> 2) Other processes, like sendmail, start exiting with the same signal
> (RTMIN+5). (I use +5 because I started seeing the problem with +0 and I
> took a wild guess that RTMIN+0 was being used for something else).
Does your copyd fork and exit after it has enabled the dnotify? Is it
still running when other processes start being killed?
> This does not seem to happen if I reboot and do not restart my copyd
> process.
>
> My system does cycle through process descriptors every few minutes (lots
> of short lived server processes) and sendmail also runs through pids
> rapidly.
>
> I'm wondering if something isn't being properly reset or cleared when a
> process exits so when the same process or fd data structure (or
> whatever) is reused inside the kernel the signals are still active
> somehow? This is a SMP Athlon, perhaps an SMP race?
That is a possibility, although I thought we had stomped on this bug.
> Do I need to configure something more in my kernel? I don't see any
> config options for realtime or rt or anything like that. And it does
> work fine after a reboot.
No, should be fine.
Can you send me a copy of your copyd (or the relevant subparts of it),
please?
-- Cheers, Stephen Rothwell sfr@canb.auug.org.au http://www.canb.auug.org.au/~sfr/ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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