[lkml]   [2004]   [Sep]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH] remove LOCK_SECTION from x86_64 spin_lock asm

* Zwane Mwaikambo <> wrote:

> On Thu, 16 Sep 2004, Ingo Molnar wrote:
> > the ebp trick is nice, but forcing a formal stack frame for every
> > function has global performance implications. Couldnt we define some
> > sort of current-> field [or current_thread_info() field] that the
> > spinlock code could set and clear, which field would be listened to by
> > profile_pc(), so that the time spent spinning would be attributed to the
> > callee? Something like:
> I think the generic route is nice but wouldn't this break with the
> following.
> taskA:
> spin_lock(lockA); // contended
> <interrupt>
> int1:
> spin_lock(lockB)
> I was thinking along the likes of a per_cpu real_pc, but realised it
> falls prey to the same problem as above... Unless we have irq threads,
> then of course your solution works.

you mean the nesting? spin_lock() should save/restore the value instead
of setting/clearing it - and fork() should initialize it to zero.

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: 2005-03-22 14:06    [W:0.072 / U:7.812 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site