Re: [linux-audio-dev] kernel 2.6.6 just out

Hi, As a service to all readers, here's an excerpt of the Changelog concerning latency: ;) akpm(a)osdl.org> [PATCH] Add mpage_writepages() scheduling point From: Jens Axboe axboe(a)suse.de> Takashi did some nice latency testing of the current kernel (with -mm writeback changes), and the biggest offender in general core is mpage_writepages(). akpm(a)osdl.org> [PATCH] ia32: 4Kb stacks (and irqstacks) patch From: Arjan van de Ven arjanv(a)redhat.com> Below is a patch to enable 4Kb stacks for x86. The goal of this is to 1) Reduce footprint per thread so that systems can run many more threads (for the java people) 2) Reduce the pressure on the VM for order > 0 allocations. We see real life workloads (granted with 2.4 but the fundamental fragmentation issue isn't solved in 2.6 and isn't solvable in theory) where this can be a problem. In addition order > 0 allocations can make the VM "stutter" and give more latency due to having to do much much more work trying to defragment akpm(a)osdl.org> [PATCH] reiserfs: scheduling latency improvements akpm(a)osdl.org> [PATCH] unmap_vmas latency improvement unmap_vmas() will cause scheduling latency when tearing down really big vmas on !CONFIG_PREEMPT. That's a bit unkind to the non-preempt case, so let's do a cond_resched() after zapping 1024 pages. So... humbly asking, is it time yet to make the switch? :-)