lkml.org 
[lkml]   [2019]   [Apr]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PATCH 19/28] locking/lockdep: Optimize irq usage check when marking lock usage bit
Thanks for review.

On Fri, 26 Apr 2019 at 03:32, Peter Zijlstra <peterz@infradead.org> wrote:
>
> On Wed, Apr 24, 2019 at 06:19:25PM +0800, Yuyang Du wrote:
>
> After only a quick read of these next patches; this is the one that
> worries me most.
>
> You did mention Frederic's patches, but I'm not entirely sure you're
> aware why he's doing them. He's preparing to split the softirq state
> into one state per softirq vector.
>
> See here:
>
> https://lkml.kernel.org/r/20190228171242.32144-14-frederic@kernel.org
> https://lkml.kernel.org/r/20190228171242.32144-15-frederic@kernel.org
>
> IOW he's going to massively explode this storage.

If I understand correctly, he is not going to.

First of all, we can divide the whole usage thing into tracking and checking.

Frederic's fine-grained soft vector state is applied to usage
tracking, i.e., which specific vectors a lock is used or enabled.

But for usage checking, which vectors are does not really matter. So,
the current size of the arrays and bitmaps are good enough. Right?

\
 
 \ /
  Last update: 2019-04-26 08:58    [W:0.066 / U:0.856 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site