Messages in this thread | | | Date | Tue, 27 Sep 2005 15:36:40 +0200 | From | Bartlomiej Zolnierkiewicz <> | Subject | Re: [patch 0/4] ide: Break ide_lock to per-hwgroup lock |
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On 9/7/05, Jens Axboe <axboe@suse.de> wrote: > On Wed, Sep 07 2005, Ravikiran G Thirumalai wrote: > > On Wed, Sep 07, 2005 at 11:19:24AM +0200, Jens Axboe wrote: > > > On Tue, Sep 06 2005, Ravikiran G Thirumalai wrote: > > > > The following patchset breaks down the global ide_lock to per-hwgroup lock. > > > > We have taken the following approach. > > > > > > Curious, what is the point of this? > > > > > > > On smp machines with multiple ide interfaces, we take per-group lock instead > > of a global lock, there by breaking the lock to per-irq hwgroups. > > I realize the theory behind breaking up locks, I'm just wondering about > this specific case. Please show actual contention data promoting this > specific case, we don't break up locks "just because". > > I'm asking because I've never heard anyone complain about IDE lock > contention and a proper patch usually comes with analysis of why it is > needed.
Since ide_lock spinlock is used for all drives as queue lock and for all controllers as IDE lock I guess that with multiple controllers there is a lot contention on it...
Breaking ide_lock is fine with me however seeing numbers would greatly help in getting wider acceptance for this change, Ravikiran?
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