[lkml]   [2005]   [May]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [patch] Real-Time Preemption, -RT-2.6.12-rc3-V0.7.46-01
On Wed, 2005-05-04 at 10:22 +0200, Ingo Molnar wrote:
> * Lee Revell <> wrote:
> > it looks like we are finally getting close to the lower limit
> > that can be achieved with PREEMPT_DESKTOP ... It's only 127 usecs, and
> > IIRC you mentioned previously that this code path can't be made
> > preemptible in !PREEMPT_RT.
> yeah, signal delivery will have to stay atomic in !PREEMPT_RT kernels.

OK. I found a few more.

When umounting, shrink_dcache_sb() will produce a 3-4 ms. bump. However
it's not clear this can be made preemptible. AFAICT the whole thing
needs to be under the dcache_lock. This one is pretty obvious so I'm
not attaching a trace.

There's also still one path in the VM related to page freeing that can
produce ~500 usec latencies but I don't have a trace handy now.

> > Since Mingming's patch will have to live in -mm for a while, can it be
> > added to the RT patchset as well?
> i think so - i'll add it to the next patch.

OK, great.


To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

 \ /
  Last update: 2005-05-04 17:08    [W:0.060 / U:4.100 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site