From: Matthew Wilcox <willy@infradead.org>
To: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
vdavydov.dev@gmail.com, mhocko@suse.com, aryabinin@virtuozzo.com,
ying.huang@intel.com, penguin-kernel@I-love.SAKURA.ne.jp,
shakeelb@google.com, jbacik@fb.com, linux-mm@kvack.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] mm: Use special value SHRINKER_REGISTERING instead list_empty() check
Date: Sun, 5 Aug 2018 05:50:04 -0700 [thread overview]
Message-ID: <20180805125004.GD3183@bombadil.infradead.org> (raw)
In-Reply-To: <e5d67774-a006-e533-d928-64a4407cbb16@virtuozzo.com>
On Sun, Aug 05, 2018 at 08:30:43AM +0300, Kirill Tkhai wrote:
> On 05.08.2018 03:03, Matthew Wilcox wrote:
> > On Sat, Aug 04, 2018 at 09:42:05PM +0300, Kirill Tkhai wrote:
> >> This is exactly the thing the patch makes. Instead of inserting a shrinker pointer
> >> to idr, it inserts a fake value SHRINKER_REGISTERING there. The patch makes impossible
> >> to dereference a shrinker unless it's completely registered.
> >
> > - id = idr_alloc(&shrinker_idr, shrinker, 0, 0, GFP_KERNEL);
> > + id = idr_alloc(&shrinker_idr, SHRINKER_REGISTERING, 0, 0, GFP_KERNEL);
> >
> > Instead:
> >
> > + id = idr_alloc(&shrinker_idr, NULL, 0, 0, GFP_KERNEL);
> >
> > ... and the rest of your patch becomes even simpler.
>
> The patch, we are discussing at the moment, does *exactly* this:
>
> https://lkml.org/lkml/2018/8/3/588
>
> It looks like you missed this hunk in the patch.
No, it does this:
+ id = idr_alloc(&shrinker_idr, SHRINKER_REGISTERING, 0, 0, GFP_KERNEL);
I'm saying do this:
+ id = idr_alloc(&shrinker_idr, NULL, 0, 0, GFP_KERNEL);
next prev parent reply other threads:[~2018-08-05 12:50 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-03 15:36 [PATCH] mm: Use special value SHRINKER_REGISTERING instead list_empty() check Kirill Tkhai
2018-08-03 22:51 ` Andrew Morton
2018-08-03 23:03 ` Matthew Wilcox
2018-08-04 18:42 ` Kirill Tkhai
2018-08-05 0:03 ` Matthew Wilcox
2018-08-05 5:30 ` Kirill Tkhai
2018-08-05 12:50 ` Matthew Wilcox [this message]
2018-08-06 8:55 ` Kirill Tkhai
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