All of lore.kernel.org
 help / color / mirror / Atom feed
From: "Odzioba, Lukasz" <lukasz.odzioba@intel.com>
To: Michal Hocko <mhocko@kernel.org>
Cc: "Hansen, Dave" <dave.hansen@intel.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"linux-mm@kvack.org" <linux-mm@kvack.org>,
	"Shutemov, Kirill" <kirill.shutemov@intel.com>,
	"Anaczkowski, Lukasz" <lukasz.anaczkowski@intel.com>
Subject: RE: mm: pages are not freed from lru_add_pvecs after process termination
Date: Fri, 6 May 2016 15:10:00 +0000	[thread overview]
Message-ID: <D6EDEBF1F91015459DB866AC4EE162CC023C402E@IRSMSX103.ger.corp.intel.com> (raw)
In-Reply-To: <20160505072122.GA4386@dhcp22.suse.cz>

On Thu 05-05-16 09:21:00, Michal Hocko wrote: 
> Or maybe the async nature of flushing turns
> out to be just impractical and unreliable and we will end up skipping
> THP (or all compound pages) for pcp LRU add cache. Let's see...

What if we simply skip lru_add pvecs for compound pages?
That way we still have compound pages on LRU's, but the problem goes
away.  It is not quite what this naïve patch does, but it works nice for me.

diff --git a/mm/swap.c b/mm/swap.c
index 03aacbc..c75d5e1 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -392,7 +392,9 @@ static void __lru_cache_add(struct page *page)
        get_page(page);
        if (!pagevec_space(pvec))
                __pagevec_lru_add(pvec);
        pagevec_add(pvec, page);
+       if (PageCompound(page))
+               __pagevec_lru_add(pvec);
        put_cpu_var(lru_add_pvec);
 }

Do we have any tests that I could use to measure performance impact
of such changes before I start to tweak it up? Or maybe it doesn't make
sense at all ?

Thanks,
Lukas

WARNING: multiple messages have this Message-ID (diff)
From: "Odzioba, Lukasz" <lukasz.odzioba@intel.com>
To: Michal Hocko <mhocko@kernel.org>
Cc: "Hansen, Dave" <dave.hansen@intel.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"linux-mm@kvack.org" <linux-mm@kvack.org>,
	"Shutemov, Kirill" <kirill.shutemov@intel.com>,
	"Anaczkowski, Lukasz" <lukasz.anaczkowski@intel.com>
Subject: RE: mm: pages are not freed from lru_add_pvecs after process termination
Date: Fri, 6 May 2016 15:10:00 +0000	[thread overview]
Message-ID: <D6EDEBF1F91015459DB866AC4EE162CC023C402E@IRSMSX103.ger.corp.intel.com> (raw)
In-Reply-To: <20160505072122.GA4386@dhcp22.suse.cz>

On Thu 05-05-16 09:21:00, Michal Hocko wrote: 
> Or maybe the async nature of flushing turns
> out to be just impractical and unreliable and we will end up skipping
> THP (or all compound pages) for pcp LRU add cache. Let's see...

What if we simply skip lru_add pvecs for compound pages?
That way we still have compound pages on LRU's, but the problem goes
away.  It is not quite what this naïve patch does, but it works nice for me.

diff --git a/mm/swap.c b/mm/swap.c
index 03aacbc..c75d5e1 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -392,7 +392,9 @@ static void __lru_cache_add(struct page *page)
        get_page(page);
        if (!pagevec_space(pvec))
                __pagevec_lru_add(pvec);
        pagevec_add(pvec, page);
+       if (PageCompound(page))
+               __pagevec_lru_add(pvec);
        put_cpu_var(lru_add_pvec);
 }

Do we have any tests that I could use to measure performance impact
of such changes before I start to tweak it up? Or maybe it doesn't make
sense at all ?

Thanks,
Lukas

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

  parent reply	other threads:[~2016-05-06 15:11 UTC|newest]

Thread overview: 50+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-04-27 17:01 mm: pages are not freed from lru_add_pvecs after process termination Odzioba, Lukasz
2016-04-27 17:01 ` Odzioba, Lukasz
2016-04-27 17:11 ` Dave Hansen
2016-04-27 17:11   ` Dave Hansen
2016-04-28 14:37   ` Michal Hocko
2016-04-28 14:37     ` Michal Hocko
2016-05-02 13:00     ` Michal Hocko
2016-05-02 13:00       ` Michal Hocko
2016-05-04 19:41       ` Odzioba, Lukasz
2016-05-04 19:41         ` Odzioba, Lukasz
2016-05-04 20:16         ` Dave Hansen
2016-05-04 20:16           ` Dave Hansen
2016-05-04 20:36         ` Michal Hocko
2016-05-04 20:36           ` Michal Hocko
2016-05-05  7:21           ` Michal Hocko
2016-05-05  7:21             ` Michal Hocko
2016-05-05 17:25             ` Odzioba, Lukasz
2016-05-05 17:25               ` Odzioba, Lukasz
2016-05-11  7:38               ` Michal Hocko
2016-05-11  7:38                 ` Michal Hocko
2016-05-06 15:10             ` Odzioba, Lukasz [this message]
2016-05-06 15:10               ` Odzioba, Lukasz
2016-05-06 16:04               ` Dave Hansen
2016-05-06 16:04                 ` Dave Hansen
2016-05-11  7:53                 ` Michal Hocko
2016-05-11  7:53                   ` Michal Hocko
2016-05-13 11:29                   ` Vlastimil Babka
2016-05-13 11:29                     ` Vlastimil Babka
2016-05-13 12:05                   ` Odzioba, Lukasz
2016-05-13 12:05                     ` Odzioba, Lukasz
2016-06-07  9:02                   ` Odzioba, Lukasz
2016-06-07  9:02                     ` Odzioba, Lukasz
2016-06-07 11:19                     ` Michal Hocko
2016-06-07 11:19                       ` Michal Hocko
2016-06-08  8:51                       ` Odzioba, Lukasz
2016-06-08  8:51                         ` Odzioba, Lukasz
2016-05-02 14:39   ` Vlastimil Babka
2016-05-02 14:39     ` Vlastimil Babka
2016-05-02 15:01     ` Kirill A. Shutemov
2016-05-02 15:01       ` Kirill A. Shutemov
2016-05-02 15:13       ` Vlastimil Babka
2016-05-02 15:13         ` Vlastimil Babka
2016-05-02 15:49       ` Dave Hansen
2016-05-02 15:49         ` Dave Hansen
2016-05-02 16:02         ` Kirill A. Shutemov
2016-05-02 16:02           ` Kirill A. Shutemov
2016-05-03  7:37           ` Michal Hocko
2016-05-03  7:37             ` Michal Hocko
2016-05-03 10:07             ` Kirill A. Shutemov
2016-05-03 10:07               ` Kirill A. Shutemov

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=D6EDEBF1F91015459DB866AC4EE162CC023C402E@IRSMSX103.ger.corp.intel.com \
    --to=lukasz.odzioba@intel.com \
    --cc=dave.hansen@intel.com \
    --cc=kirill.shutemov@intel.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=lukasz.anaczkowski@intel.com \
    --cc=mhocko@kernel.org \
    /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.