On Wed, 2008-01-02 at 22:12 +1100, Nick Piggin wrote: > On Wednesday 02 January 2008 22:01, Peter Zijlstra wrote:
> > I've seen 1s+ desktop latencies due to PREEMPT_BKL when I was still > > using reiserfs. > > Fair enough; so the former ifdefery would be preferable for now then. To be honest, I must mention that the load that did that was a kernel build -j5 on a dual socket Athlon MP box. With a current kernel and XFS that load is making the box slow but its still very servicable. > > Both reiserfs and tty were fighting for the bkl and massive prio > > inversion ensued. Turning PREEMPT_BKL off made the system usable again. > > Are either of those subsystems actually using the BKL to protect against > anything else (than themselves)? I doubt it. IIRC Alan is working on getting tty BKL free. > It would be sweet to have them use > private mutexes for the job instead (although even then it probably > wouldn't be a straight conversion)... I tried a quick conversion of reiser3 at the time, but it really wants a recursive lock and I couldn't be bothered to fix a 'legacy' filesystem so I just gave up and converted the filesystem to XFS. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
