From: Roman Gushchin <guro@fb.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>, <linux-mm@kvack.org>,
Michal Hocko <mhocko@suse.com>,
Johannes Weiner <hannes@cmpxchg.org>,
<linux-fsdevel@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
<kernel-team@fb.com>
Subject: Re: [PATCH 3/3] dcache: account external names as indirectly reclaimable memory
Date: Fri, 6 Apr 2018 11:32:56 +0100 [thread overview]
Message-ID: <20180406103250.GA3717@castle> (raw)
In-Reply-To: <20180405151123.df20d12168d8a38f7a6b02b5@linux-foundation.org>
On Thu, Apr 05, 2018 at 03:11:23PM -0700, Andrew Morton wrote:
> On Tue, 13 Mar 2018 00:45:32 +0000 Al Viro <viro@ZenIV.linux.org.uk> wrote:
>
> > On Mon, Mar 12, 2018 at 10:36:38PM +0000, Roman Gushchin wrote:
> >
> > > Ah, I see...
> > >
> > > I think, it's better to account them when we're actually freeing,
> > > otherwise we will have strange path:
> > > (indirectly) reclaimable -> unreclaimable -> free
> > >
> > > Do you agree?
> >
> > > +static void __d_free_external_name(struct rcu_head *head)
> > > +{
> > > + struct external_name *name;
> > > +
> > > + name = container_of(head, struct external_name, u.head);
> > > +
> > > + mod_node_page_state(page_pgdat(virt_to_page(name)),
> > > + NR_INDIRECTLY_RECLAIMABLE_BYTES,
> > > + -ksize(name));
> > > +
> > > + kfree(name);
> > > +}
> >
> > Maybe, but then you want to call that from __d_free_external() and from
> > failure path in __d_alloc() as well. Duplicating something that convoluted
> > and easy to get out of sync is just asking for trouble.
>
> So.. where are we at with this issue?
I assume that commit 0babe6fe1da3 ("dcache: fix indirectly reclaimable memory accounting")
address the issue.
__d_free_external_name() is now called from all release paths (including __d_free_external())
and is the only place where NR_INDIRECTLY_RECLAIMABLE_BYTES is decremented.
__d_alloc()'s error path is slightly different, because I bump NR_INDIRECTLY_RECLAIMABLE_BYTES
in a very last moment, when it's already clear, that no errors did occur.
So we don't need to increase and decrease the counter back and forth.
Thank you!
next prev parent reply other threads:[~2018-04-06 10:32 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-05 13:37 [PATCH 0/3] indirectly reclaimable memory Roman Gushchin
2018-03-05 13:37 ` [PATCH 1/3] mm: introduce NR_INDIRECTLY_RECLAIMABLE_BYTES Roman Gushchin
2018-04-11 13:16 ` Vlastimil Babka
2018-04-11 13:56 ` Roman Gushchin
2018-04-12 6:52 ` Vlastimil Babka
2018-04-12 11:52 ` Michal Hocko
2018-04-12 14:38 ` Roman Gushchin
2018-04-12 14:46 ` Michal Hocko
2018-04-12 14:57 ` Roman Gushchin
2018-04-13 6:59 ` Michal Hocko
2018-04-13 12:13 ` vinayak menon
2018-04-25 3:49 ` Vijayanand Jitta
2018-04-25 12:52 ` Roman Gushchin
2018-04-25 15:47 ` Vlastimil Babka
2018-04-25 16:48 ` Roman Gushchin
2018-04-25 17:02 ` Vlastimil Babka
2018-04-25 17:23 ` Roman Gushchin
2018-04-25 15:55 ` Matthew Wilcox
2018-04-25 16:59 ` Vlastimil Babka
2018-03-05 13:37 ` [PATCH 2/3] mm: add indirectly reclaimable memory to MemAvailable Roman Gushchin
2018-03-05 13:47 ` Roman Gushchin
2018-03-05 13:37 ` [PATCH 2/3] mm: treat indirectly reclaimable memory as available in MemAvailable Roman Gushchin
2018-03-05 13:37 ` [PATCH 3/3] dcache: account external names as indirectly reclaimable memory Roman Gushchin
2018-03-12 21:17 ` Al Viro
2018-03-12 22:36 ` Roman Gushchin
2018-03-13 0:45 ` Al Viro
2018-04-05 22:11 ` Andrew Morton
2018-04-06 10:32 ` Roman Gushchin [this message]
2018-04-13 13:35 ` Minchan Kim
2018-04-13 13:59 ` Michal Hocko
2018-04-13 14:20 ` Vlastimil Babka
2018-04-13 14:28 ` Michal Hocko
2018-04-13 14:37 ` Johannes Weiner
2018-04-16 11:41 ` Michal Hocko
2018-04-16 12:06 ` Vlastimil Babka
2018-04-16 12:27 ` Michal Hocko
2018-04-16 19:57 ` Vlastimil Babka
2018-04-17 6:44 ` Michal Hocko
2018-04-16 13:09 ` Matthew Wilcox
2018-04-17 11:24 ` Roman Gushchin
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