lkml.org 
[lkml]   [2002]   [Feb]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [RFC] New locking primitive for 2.5
Date
From
Martin Wirth <Martin.Wirth@dlr.de> said:
> This is a request for comment on a new locking primitive
> called a combilock.
>
> The goal of this development is:
>
> 1. To allow for a better SMP scalability of semaphores used as Mutex
> 2. As a replacement for long held spinlocks in an preemptible kernel
>
> The new lock uses a combination of a spinlock and a (mutex-)semaphore.
> You can lock it for short-term issues in a spin-lock mode:
>
> combi_spin_lock(struct combilock *x)
> combi_spin_unlock(struct combilock *x)
>
> and for longer lasting tasks in a sleeping mode by:
>
> combi_mutex_lock(struct combilock *x)
> combi_mutex_unlock(struct combilock *x)

Can you sleep if acquired as the spinlock?

Is there any measurable (or at least plausible reason why there should be)
performance improvement? (No, "should make preemptible kernel faster"
doesn't cut it at all for me). Or any hope that it will substantially
simplify kernel programming with _no_ performance degradation by replacing
both semphores and spinlocks?
--
Horst von Brand http://counter.li.org # 22616
-
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 13:24    [W:0.146 / U:3.720 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site