[OpenAFS-devel] Linux and memory mapped files hang the client, particularly when the client is OpenMosix.

[George Talbot]

Thanks for the patch.  I'll take a look at it.

By the way, in case I didn't mention, I'm seeing this on my 2-way Xeon
SMP box, fwiw.

--George


On Thu, 2003-07-10 at 16:15, Derrick J Brashear wrote:
> On Thu, 10 Jul 2003, George Talbot wrote:
> 
> > Hi,
> >
> > We have a problem here with clients that make heavy use of mmap() on
> > files stored on an AFS server.  The program doing the mmap() access will
> > hang, as will top, ps, etc.  I'm using Linux kernel 2.4.20, with OpenAFS
> > 1.2.8, and OpenMosix, though I don't think it's OpenMosix, because if I
> > recompile the kernel without OpenMosix, I still get hangs, just not as
> > frequently.
> >
> > So I found this patch:
> >
> > https://lists.openafs.org/pipermail/openafs-devel/2002-December/003624.html
> 
> The patch we ended up applying to the head only, and not to any 1.2.x yet,
> was:
> http://www.openafs.org/cgi-bin/wdelta/linux-execsorwrites-at-close-20030328?diff&f=u
> 
> > This patch does not work for us.  I did some further investigation of
> > where the program is hanging.  The programs hang in
> > afs_linux_vma_close() right when this function tries to acquire a write
> []
> 
> > At this point afs_linux_vma_close() gets called because the application
> > is unmapping the file, acquires the AFS_GLOCK(), and blocks trying to
> > acquire the shared lock.
> >
> > Then, I believe that afs_GetDCache() runs again after the read
> > completes, tries to acquire the AFS_GLOCK() and blocks.
> 
> I will look at this soon unless someone beats me to it.
> 
> _______________________________________________
> OpenAFS-devel mailing list
> OpenAFS-devel@openafs.org
> https://lists.openafs.org/mailman/listinfo/openafs-devel