Messages in this thread |  | | From | "John Hawkes" <> | Subject | Re: Locking comment on shrink_caches() | Date | Wed, 26 Sep 2001 09:52:12 -0700 |
| |
From: "Andrew Morton" <akpm@zip.com.au> > > John Hawkes from SGI had published some AIM7 numbers that showed > > pagecache_lock to be a bottleneck above 4 processors. At 32 processors, > > half the CPU cycles were spent on waiting for pagecache_lock. The > > thread is at - > > > > http://marc.theaimsgroup.com/?l=lse-tech&m=98459051027582&w=2 > > > > That's NUMA hardware. The per-hashqueue locking change made > a big improvement on that hardware. But when it was used on > Intel hardware it made no measurable difference at all.
More specifically, that was on SGI Origin2000 32p mips64 ccNUMA hardware. The pagecache_lock bottleneck is substantially less on SGI Itanium ccNUMA hardware running those AIM7 workloads. I'm seeing moderately significant contention on the Big Kernel Lock, mostly from sys_lseek() and ext2_get_block().
John Hawkes hawkes@sgi.com
- 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/
|  |