![]() | |||||||||||||
Messages in this thread |
Robert Love wrote: > > On Tue, 2002-01-29 at 20:26, Andrew Morton wrote: > > > Just a little word of caution here. Remember the > > apache-flock-synchronisation fiasco, where removal > > of the BKL halved Apache throughput on 8-way x86. > > > > This was because the BKL removal turned serialisation > > on a quick codepath from a spinlock into a schedule(). > > I feared this too, but eventually I decided it was worth it and > benchmarks backed that up. If nothing else this is yet-another-excuse > for locks that can spin-then-sleep. > > I posted dbench results, which show a positive gain even on 2-way for > multiple client loads. > But dbench does lots of seeking against *different* files, so removal of a shared lock will help there. But an application where multiple CPUs lseek and write the *same* file could take a hit.... (And where's the locking for (non-atomic) i_size in sys_stat()) - - 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/ | ||||||||||||
| Last update: 2005-03-22 12:15 [W:0.363 / U:0.730 seconds] ©2003-2008 Jasper Spaans | |||||||||||||