Messages in this thread | | | Date | Fri, 3 May 2002 17:31:09 +1000 | From | Stephen Rothwell <> | Subject | Re: dnotify oddity in 2.4.19pre6aa1 |
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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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