-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 12/14/2011 01:27 PM, Mark Fasheh wrote: > Hey Christoph, > > On Tue, Dec 13, 2011 at 09:40:40PM -0500, Christoph Hellwig wrote: >> Can you explain the story behid this patch in SLES11SP1? > > We were looking at some performance issues and needed a bit more > information on the amount of time spent in ilock. I can give you > more specifics if you want, I just have to dig up the e-mails (it's > been a while). That's pretty much the explanation. With heavy reader load, buffered writes were stalling for 80 ms and sometimes longer. I suspected it was contention on the ilock and the tracing with that patch demonstrated a delay there. Since we were chasing a similar issue at another site, it seemed worthwhile to just keep it around. We're still tracking down the cause. I'm not sure if more recent kernels have the same issue as there's been quite a lot of churn. - -Jeff - -- Jeff Mahoney SUSE Labs -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.18 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iQIcBAEBAgAGBQJO6PfwAAoJEB57S2MheeWyE+MQAIeh/VUfWExpjsgdBbkSj4jv 7sJQW2WweYpHHZdLnGx5Pn4cDO6/2YyqNXfwAGZk2yoXTcycykR7ZVHLGEyyNDLV BrKUvcDG/5XYTx3B64yPge8rNY9YIiy2e/c+pbwPeSnDPMY9976igqbrC5qaJ31a 1a/REm/MpDkGV7NcS4XYjbZwl0bP6BBJib0fnCrvkmWo7mtuzwz1XMpORGLWltOg EhRTTgh+HRc1zlqknz5+ceMghky+GTp56/3YPslbco61uI9XmKzLc/bi1iNgda24 gy6wAIRk0EwPd9o2Wl+Jvvm79YvTE2SvkjDzHz3exOAX3JTMVnF//7bjVfPg7A9f xyHQ7GQJRWQwIXuGVqi7JciN5/5IKOdkrGILIIC1osFjr7z894xGgQejNhqxuXNE B06WUJ2PLYEOCKLCnH75OwCsDRqdj7N+yPbxGJIZeAjdiH6r2tanAAtYAtqdn+3T J7sdsm/Kvod4wgKBLJWk/rvTI/i1pjoqNaeF0rdXsQbqGI7C9OKeNfIjilt0HT8h 9EIaoy3KjnGmAU1pouHZro2hR1Ec8Ni09DM5GMQeGTIAPvgTgP8oHB/MPFIM9Jnl QxfLJ5o3bxvB3u2aDJQta3+V/9TQPfELtokjjk34GjAcaxBZT7mTy8lVOHVL1Srg 86cHVs6PDRXQf7CeoX+N =Cjlo -----END PGP SIGNATURE----- _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
