linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Alex Shi <alex.shi@linux.alibaba.com>
To: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	Mel Gorman <mgorman@techsingularity.net>,
	Tejun Heo <tj@kernel.org>, Hugh Dickins <hughd@google.com>,
	Konstantin Khlebnikov <khlebnikov@yandex-team.ru>,
	Daniel Jordan <daniel.m.jordan@oracle.com>,
	Yang Shi <yang.shi@linux.alibaba.com>,
	Matthew Wilcox <willy@infradead.org>,
	Johannes Weiner <hannes@cmpxchg.org>,
	kbuild test robot <lkp@intel.com>, linux-mm <linux-mm@kvack.org>,
	LKML <linux-kernel@vger.kernel.org>,
	cgroups@vger.kernel.org, Shakeel Butt <shakeelb@google.com>,
	Joonsoo Kim <iamjoonsoo.kim@lge.com>,
	Wei Yang <richard.weiyang@gmail.com>,
	"Kirill A. Shutemov" <kirill@shutemov.name>,
	Michal Hocko <mhocko@kernel.org>,
	Vladimir Davydov <vdavydov.dev@gmail.com>,
	Rong Chen <rong.a.chen@intel.com>
Subject: Re: [PATCH v16 18/22] mm/lru: replace pgdat lru_lock with lruvec lock
Date: Mon, 20 Jul 2020 13:47:09 +0800	[thread overview]
Message-ID: <27eb389d-b5f9-fe03-2e57-15c351629efc@linux.alibaba.com> (raw)
In-Reply-To: <CAKgT0UestD7cU+3aqg3a9JT4bTXVYQpjGbwoC2-bOBHPY5xn6A@mail.gmail.com>



在 2020/7/19 下午11:14, Alexander Duyck 写道:
>> Compare to move to tail, how about to move it to head of struct, which is
>> close to lru list? Did you have some data of the place change?
> I don't have specific data, just anecdotal evidence from the past that
> usually you want to keep locks away from read-mostly items since they
> cause obvious cache thrash. My concern was more with the other fields
> in the structure such as pgdat since it should be a static value and
> having it evicted would likely be more expensive than just leaving the
> cacheline as it is.
> 

Thanks for comments, Alex.

So, sounds like moving the lru_lock to head of struct lruvec could be better.

>> -       __mod_zone_page_state(zone, NR_MLOCK, delta_munlocked);
>> +       if (delta_munlocked)
>> +               __mod_zone_page_state(zone, NR_MLOCK, delta_munlocked);
>>         if (lruvec)
>>                 unlock_page_lruvec_irq(lruvec);
> Why not just wrap the entire thing in a check for "lruvec"? Yes you
> could theoretically be modding with a value of 0, but it avoids a
> secondary unnecessary check and branching.

Right, and the delta_munlocked value could be checked inside the accounting
func

Thanks!

  reply	other threads:[~2020-07-20  5:47 UTC|newest]

Thread overview: 66+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-11  0:58 [PATCH v16 00/22] per memcg lru_lock Alex Shi
2020-07-11  0:58 ` [PATCH v16 01/22] mm/vmscan: remove unnecessary lruvec adding Alex Shi
2020-07-11  0:58 ` [PATCH v16 02/22] mm/page_idle: no unlikely double check for idle page counting Alex Shi
2020-07-11  0:58 ` [PATCH v16 03/22] mm/compaction: correct the comments of compact_defer_shift Alex Shi
2020-07-11  0:58 ` [PATCH v16 04/22] mm/compaction: rename compact_deferred as compact_should_defer Alex Shi
2020-07-11  0:58 ` [PATCH v16 05/22] mm/thp: move lru_add_page_tail func to huge_memory.c Alex Shi
2020-07-16  8:59   ` Alex Shi
2020-07-16 13:17     ` Kirill A. Shutemov
2020-07-17  5:13       ` Alex Shi
2020-07-20  8:37         ` Kirill A. Shutemov
2020-07-11  0:58 ` [PATCH v16 06/22] mm/thp: clean up lru_add_page_tail Alex Shi
2020-07-20  8:43   ` Kirill A. Shutemov
2020-07-11  0:58 ` [PATCH v16 07/22] mm/thp: remove code path which never got into Alex Shi
2020-07-20  8:43   ` Kirill A. Shutemov
2020-07-11  0:58 ` [PATCH v16 08/22] mm/thp: narrow lru locking Alex Shi
2020-07-11  0:58 ` [PATCH v16 09/22] mm/memcg: add debug checking in lock_page_memcg Alex Shi
2020-07-11  0:58 ` [PATCH v16 10/22] mm/swap: fold vm event PGROTATED into pagevec_move_tail_fn Alex Shi
2020-07-11  0:58 ` [PATCH v16 11/22] mm/lru: move lru_lock holding in func lru_note_cost_page Alex Shi
2020-07-11  0:58 ` [PATCH v16 12/22] mm/lru: move lock into lru_note_cost Alex Shi
2020-07-11  0:58 ` [PATCH v16 13/22] mm/lru: introduce TestClearPageLRU Alex Shi
2020-07-16  9:06   ` Alex Shi
2020-07-16 21:12   ` Alexander Duyck
2020-07-17  7:45     ` Alex Shi
2020-07-17 18:26       ` Alexander Duyck
2020-07-19  4:45         ` Alex Shi
2020-07-19 11:24           ` Alex Shi
2020-07-11  0:58 ` [PATCH v16 14/22] mm/thp: add tail pages into lru anyway in split_huge_page() Alex Shi
2020-07-17  9:30   ` Alex Shi
2020-07-20  8:49     ` Kirill A. Shutemov
2020-07-20  9:04       ` Alex Shi
2020-07-11  0:58 ` [PATCH v16 15/22] mm/compaction: do page isolation first in compaction Alex Shi
2020-07-16 21:32   ` Alexander Duyck
2020-07-17  5:09     ` Alex Shi
2020-07-17 16:09       ` Alexander Duyck
2020-07-19  3:59         ` Alex Shi
2020-07-11  0:58 ` [PATCH v16 16/22] mm/mlock: reorder isolation sequence during munlock Alex Shi
2020-07-17 20:30   ` Alexander Duyck
2020-07-19  3:55     ` Alex Shi
2020-07-20 18:51       ` Alexander Duyck
2020-07-21  9:26         ` Alex Shi
2020-07-21 13:51           ` Alex Shi
2020-07-11  0:58 ` [PATCH v16 17/22] mm/swap: serialize memcg changes during pagevec_lru_move_fn Alex Shi
2020-07-11  0:58 ` [PATCH v16 18/22] mm/lru: replace pgdat lru_lock with lruvec lock Alex Shi
2020-07-17 21:38   ` Alexander Duyck
2020-07-18 14:15     ` Alex Shi
2020-07-19  9:12       ` Alex Shi
2020-07-19 15:14         ` Alexander Duyck
2020-07-20  5:47           ` Alex Shi [this message]
2020-07-11  0:58 ` [PATCH v16 19/22] mm/lru: introduce the relock_page_lruvec function Alex Shi
2020-07-17 22:03   ` Alexander Duyck
2020-07-18 14:01     ` Alex Shi
2020-07-11  0:58 ` [PATCH v16 20/22] mm/vmscan: use relock for move_pages_to_lru Alex Shi
2020-07-17 21:44   ` Alexander Duyck
2020-07-18 14:15     ` Alex Shi
2020-07-11  0:58 ` [PATCH v16 21/22] mm/pgdat: remove pgdat lru_lock Alex Shi
2020-07-17 21:09   ` Alexander Duyck
2020-07-18 14:17     ` Alex Shi
2020-07-11  0:58 ` [PATCH v16 22/22] mm/lru: revise the comments of lru_lock Alex Shi
2020-07-11  1:02 ` [PATCH v16 00/22] per memcg lru_lock Alex Shi
2020-07-16  8:49 ` Alex Shi
2020-07-16 14:11 ` Alexander Duyck
2020-07-17  5:24   ` Alex Shi
2020-07-19 15:23     ` Hugh Dickins
2020-07-20  3:01       ` Alex Shi
2020-07-20  4:47         ` Hugh Dickins
2020-07-20  7:30 ` Alex Shi

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=27eb389d-b5f9-fe03-2e57-15c351629efc@linux.alibaba.com \
    --to=alex.shi@linux.alibaba.com \
    --cc=akpm@linux-foundation.org \
    --cc=alexander.duyck@gmail.com \
    --cc=cgroups@vger.kernel.org \
    --cc=daniel.m.jordan@oracle.com \
    --cc=hannes@cmpxchg.org \
    --cc=hughd@google.com \
    --cc=iamjoonsoo.kim@lge.com \
    --cc=khlebnikov@yandex-team.ru \
    --cc=kirill@shutemov.name \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=lkp@intel.com \
    --cc=mgorman@techsingularity.net \
    --cc=mhocko@kernel.org \
    --cc=richard.weiyang@gmail.com \
    --cc=rong.a.chen@intel.com \
    --cc=shakeelb@google.com \
    --cc=tj@kernel.org \
    --cc=vdavydov.dev@gmail.com \
    --cc=willy@infradead.org \
    --cc=yang.shi@linux.alibaba.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).