All of lore.kernel.org
 help / color / mirror / Atom feed
From: Matthew Wilcox <willy@infradead.org>
To: Hao Lee <haolee.swjtu@gmail.com>
Cc: linux-mm@kvack.org, hannes@cmpxchg.org, mhocko@kernel.org,
	vdavydov.dev@gmail.com, shakeelb@google.com,
	cgroups@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] mm: reduce spinlock contention in release_pages()
Date: Wed, 24 Nov 2021 15:57:58 +0000	[thread overview]
Message-ID: <YZ5hBtWPBpHDWzE4@casper.infradead.org> (raw)
In-Reply-To: <20211124151915.GA6163@haolee.io>

On Wed, Nov 24, 2021 at 03:19:15PM +0000, Hao Lee wrote:
> When several tasks are terminated simultaneously, lots of pages will be
> released, which can cause severe spinlock contention. Other tasks which
> are running on the same core will be seriously affected. We can yield
> cpu to fix this problem.

The realtime people will eat you alive for this suggestion.

> +++ b/mm/swap.c
> @@ -960,8 +960,14 @@ void release_pages(struct page **pages, int nr)
>  		if (PageLRU(page)) {
>  			struct lruvec *prev_lruvec = lruvec;
>  
> -			lruvec = folio_lruvec_relock_irqsave(folio, lruvec,
> +retry:
> +			lruvec = folio_lruvec_tryrelock_irqsave(folio, lruvec,
>  									&flags);
> +			if (!lruvec) {
> +				cond_resched();
> +				goto retry;
> +			}
> +
>  			if (prev_lruvec != lruvec)

WARNING: multiple messages have this Message-ID (diff)
From: Matthew Wilcox <willy-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>
To: Hao Lee <haolee.swjtu-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Cc: linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org,
	hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org,
	mhocko-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org,
	vdavydov.dev-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org,
	shakeelb-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org,
	cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: Re: [PATCH] mm: reduce spinlock contention in release_pages()
Date: Wed, 24 Nov 2021 15:57:58 +0000	[thread overview]
Message-ID: <YZ5hBtWPBpHDWzE4@casper.infradead.org> (raw)
In-Reply-To: <20211124151915.GA6163-09FY7RZCRvthl2p70BpVqQ@public.gmane.org>

On Wed, Nov 24, 2021 at 03:19:15PM +0000, Hao Lee wrote:
> When several tasks are terminated simultaneously, lots of pages will be
> released, which can cause severe spinlock contention. Other tasks which
> are running on the same core will be seriously affected. We can yield
> cpu to fix this problem.

The realtime people will eat you alive for this suggestion.

> +++ b/mm/swap.c
> @@ -960,8 +960,14 @@ void release_pages(struct page **pages, int nr)
>  		if (PageLRU(page)) {
>  			struct lruvec *prev_lruvec = lruvec;
>  
> -			lruvec = folio_lruvec_relock_irqsave(folio, lruvec,
> +retry:
> +			lruvec = folio_lruvec_tryrelock_irqsave(folio, lruvec,
>  									&flags);
> +			if (!lruvec) {
> +				cond_resched();
> +				goto retry;
> +			}
> +
>  			if (prev_lruvec != lruvec)

  reply	other threads:[~2021-11-24 15:58 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-11-24 15:19 [PATCH] mm: reduce spinlock contention in release_pages() Hao Lee
2021-11-24 15:19 ` Hao Lee
2021-11-24 15:57 ` Matthew Wilcox [this message]
2021-11-24 15:57   ` Matthew Wilcox
2021-11-25  3:13   ` Hao Lee
2021-11-25  3:13     ` Hao Lee
2021-11-24 16:31 ` Michal Hocko
2021-11-24 16:31   ` Michal Hocko
2021-11-25  3:24   ` Hao Lee
2021-11-25  3:24     ` Hao Lee
2021-11-25  3:30     ` Matthew Wilcox
2021-11-25  3:30       ` Matthew Wilcox
2021-11-25  8:02       ` Hao Lee
2021-11-25 10:01         ` Michal Hocko
2021-11-25 12:31           ` Hao Lee
2021-11-25 14:18             ` Michal Hocko
2021-11-25 14:18               ` Michal Hocko
2021-11-26  6:50               ` Hao Lee
2021-11-26  6:50                 ` Hao Lee
2021-11-26 10:46                 ` Michal Hocko
2021-11-26 10:46                   ` Michal Hocko
2021-11-26 16:26                   ` Hao Lee
2021-11-26 16:26                     ` Hao Lee
2021-11-29  8:39                     ` Michal Hocko
2021-11-29 13:23                       ` Matthew Wilcox
2021-11-29 13:23                         ` Matthew Wilcox
2021-11-29 13:39                         ` Michal Hocko
2021-11-29 13:39                           ` Michal Hocko
2021-11-25 18:04         ` Matthew Wilcox
2021-11-25 18:04           ` Matthew Wilcox
2021-11-26  6:54           ` Hao Lee
2021-11-26  6:54             ` Hao Lee

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=YZ5hBtWPBpHDWzE4@casper.infradead.org \
    --to=willy@infradead.org \
    --cc=cgroups@vger.kernel.org \
    --cc=hannes@cmpxchg.org \
    --cc=haolee.swjtu@gmail.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=mhocko@kernel.org \
    --cc=shakeelb@google.com \
    --cc=vdavydov.dev@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.