All of lore.kernel.org
 help / color / mirror / Atom feed
From: Andrea Arcangeli <aarcange@redhat.com>
To: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Michel Lespinasse <walken@google.com>,
	Minchan Kim <minchan.kim@gmail.com>,
	Hugh Dickins <hughd@google.com>,
	linux-mm@kvack.org, Andrew Morton <akpm@linux-foundation.org>,
	Rik van Riel <riel@redhat.com>, Mel Gorman <mgorman@suse.de>,
	Johannes Weiner <jweiner@redhat.com>,
	KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
	Shaohua Li <shaohua.li@intel.com>
Subject: Re: [RFC PATCH 0/3] page count lock for simpler put_page
Date: Sun, 14 Aug 2011 01:56:11 +0200	[thread overview]
Message-ID: <20110813235611.GA16581@redhat.com> (raw)
In-Reply-To: <20110813015741.GZ2395@linux.vnet.ibm.com>

On Fri, Aug 12, 2011 at 06:57:41PM -0700, Paul E. McKenney wrote:
> But if we are getting much below 100 milliseconds, we need to rethink
> this.

The delay may be low in some corner case but this still benefits by
running it only once. You can mmap() bzero, mremap(+4096) (if mremap
moves the pages to a not aligned 2m address, it forces a
split_huge_page, an hardware issue) and all pages will be splitted in
potentially less than 100msec if they're only a few. At least we'll be
running synchronize_rcu only once instead of for every hugepage, as
long as it runs only once I guess we're ok. Normally it shouldn't
happen so fast. My current /proc/vmstat says there are 271 splits for
97251 THP allocated and they're not so likely to have happened within
100msec.

--
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/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

  reply	other threads:[~2011-08-13 23:56 UTC|newest]

Thread overview: 34+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-08-04 21:07 [RFC PATCH 0/3] page count lock for simpler put_page Michel Lespinasse
2011-08-04 21:07 ` [RFC PATCH 1/3] mm: Replace naked page->_count accesses with accessor functions Michel Lespinasse
2011-08-04 21:07 ` [RFC PATCH 2/3] mm: page count lock Michel Lespinasse
2011-08-07 14:00   ` Minchan Kim
2011-08-04 21:07 ` [RFC PATCH 3/3] mm: get_first_page_unless_zero() Michel Lespinasse
2011-08-07 14:13   ` Minchan Kim
2011-08-05  6:39 ` [RFC PATCH 0/3] page count lock for simpler put_page Michel Lespinasse
2011-08-07 14:25   ` Minchan Kim
2011-08-09 11:04     ` Michel Lespinasse
2011-08-09 22:22       ` Minchan Kim
2011-08-12 22:35         ` Michel Lespinasse
2011-08-13  4:07           ` Minchan Kim
2011-08-12 15:36       ` Andrea Arcangeli
2011-08-12 16:08         ` SPAM: " Paul E. McKenney
2011-08-12 16:43           ` Andrea Arcangeli
2011-08-12 17:27             ` Paul E. McKenney
2011-08-12 23:45               ` Michel Lespinasse
2011-08-13  1:57                 ` Paul E. McKenney
2011-08-13 23:56                   ` Andrea Arcangeli [this message]
2011-08-13  4:18             ` Minchan Kim
2011-08-12 16:57           ` Johannes Weiner
2011-08-12 17:08             ` Andrea Arcangeli
2011-08-12 17:52               ` Johannes Weiner
2011-08-12 18:13                 ` Paul E. McKenney
2011-08-12 19:05                   ` Johannes Weiner
2011-08-12 22:14                     ` Paul E. McKenney
2011-08-12 22:22                 ` Andrea Arcangeli
2011-08-12 18:03               ` Paul E. McKenney
2011-08-12 17:41             ` Paul E. McKenney
2011-08-12 17:56               ` Johannes Weiner
2011-08-12 23:02           ` Michel Lespinasse
2011-08-12 22:50         ` Michel Lespinasse
2011-08-13  4:11         ` Minchan Kim
2011-08-12 16:58   ` Andrea Arcangeli

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=20110813235611.GA16581@redhat.com \
    --to=aarcange@redhat.com \
    --cc=akpm@linux-foundation.org \
    --cc=hughd@google.com \
    --cc=jweiner@redhat.com \
    --cc=kosaki.motohiro@jp.fujitsu.com \
    --cc=linux-mm@kvack.org \
    --cc=mgorman@suse.de \
    --cc=minchan.kim@gmail.com \
    --cc=paulmck@linux.vnet.ibm.com \
    --cc=riel@redhat.com \
    --cc=shaohua.li@intel.com \
    --cc=walken@google.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.