linux-fsdevel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Waiman Long <longman@redhat.com>
To: Alexander Viro <viro@zeniv.linux.org.uk>,
	Jonathan Corbet <corbet@lwn.net>
Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	linux-mm@kvack.org, linux-doc@vger.kernel.org,
	"Luis R. Rodriguez" <mcgrof@kernel.org>,
	Kees Cook <keescook@chromium.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Jan Kara <jack@suse.cz>,
	"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Ingo Molnar <mingo@kernel.org>,
	Miklos Szeredi <mszeredi@redhat.com>,
	Matthew Wilcox <willy@infradead.org>,
	Larry Woodman <lwoodman@redhat.com>,
	James Bottomley <James.Bottomley@HansenPartnership.com>,
	"Wangkai (Kevin C)" <wangkai86@huawei.com>,
	Michal Hocko <mhocko@kernel.org>,
	Waiman Long <longman@redhat.com>
Subject: [PATCH v3 0/4] fs/dcache: Track # of negative dentries
Date: Tue, 11 Sep 2018 15:18:22 -0400	[thread overview]
Message-ID: <1536693506-11949-1-git-send-email-longman@redhat.com> (raw)

 v2->v3:
  - With confirmation that the dummy array in dentry_stat structure
    was never a replacement of a previously used field, patch 3 is now
    reverted back to use one of dummy field as the negative dentry count
    instead of adding a new field.

 v1->v2:
  - Clarify what the new nr_dentry_negative per-cpu counter is tracking
    and open-code the increment and decrement as suggested by Dave Chinner.
  - Append the new nr_dentry_negative count as the 7th element of dentry-state
    instead of replacing one of the dummy entries.
  - Remove patch "fs/dcache: Make negative dentries easier to be
    reclaimed" for now as I need more time to think about what
    to do with it.
  - Add 2 more patches to address issues found while reviewing the
    dentry code.
  - Add another patch to change the conditional branch of
    nr_dentry_negative accounting to conditional move so as to reduce
    the performance impact of the accounting code.

This patchset addresses 2 issues found in the dentry code and adds a
new nr_dentry_negative per-cpu counter to track the total number of
negative dentries in all the LRU lists.

Patch 1 fixes a bug in the accounting of nr_dentry_unused in
shrink_dcache_sb().

Patch 2 removes the ____cacheline_aligned_in_smp tag from super_block
LRU lists.

Patch 3 adds the new nr_dentry_negative per-cpu counter.

Patch 4 removes conditional branches in nr_dentry_negative accounting
code.

Various filesystem related tests were run and no statistically
significant changes in performance was observed.

Waiman Long (4):
  fs/dcache: Fix incorrect nr_dentry_unused accounting in
    shrink_dcache_sb()
  fs: Don't need to put list_lru into its own cacheline
  fs/dcache: Track & report number of negative dentries
  fs/dcache: Eliminate branches in nr_dentry_negative accounting

 Documentation/sysctl/fs.txt | 26 +++++++++++++---------
 fs/dcache.c                 | 54 ++++++++++++++++++++++++++++++++++++++++-----
 include/linux/dcache.h      |  7 +++---
 include/linux/fs.h          |  9 ++++----
 4 files changed, 74 insertions(+), 22 deletions(-)

-- 
1.8.3.1

             reply	other threads:[~2018-09-11 19:18 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-09-11 19:18 Waiman Long [this message]
2018-09-11 19:18 ` [PATCH v3 1/4] fs/dcache: Fix incorrect nr_dentry_unused accounting in shrink_dcache_sb() Waiman Long
2018-09-11 22:02   ` Dave Chinner
2018-09-12 15:41     ` Waiman Long
2018-09-11 19:18 ` [PATCH v3 2/4] fs: Don't need to put list_lru into its own cacheline Waiman Long
2018-09-11 22:02   ` Dave Chinner
2018-09-11 19:18 ` [PATCH v3 3/4] fs/dcache: Track & report number of negative dentries Waiman Long
2018-09-11 22:08   ` Dave Chinner
2018-09-12 15:40     ` Waiman Long
2018-09-11 19:18 ` [PATCH v3 4/4] fs/dcache: Eliminate branches in nr_dentry_negative accounting Waiman Long
2018-09-11 22:13   ` Dave Chinner
2018-09-12 15:44     ` Waiman Long
2018-09-12  2:36   ` Matthew Wilcox
2018-09-12 15:49     ` Waiman Long
2018-09-12 15:55       ` Matthew Wilcox
2018-09-12 16:11         ` Waiman Long

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=1536693506-11949-1-git-send-email-longman@redhat.com \
    --to=longman@redhat.com \
    --cc=James.Bottomley@HansenPartnership.com \
    --cc=akpm@linux-foundation.org \
    --cc=corbet@lwn.net \
    --cc=jack@suse.cz \
    --cc=keescook@chromium.org \
    --cc=linux-doc@vger.kernel.org \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=lwoodman@redhat.com \
    --cc=mcgrof@kernel.org \
    --cc=mhocko@kernel.org \
    --cc=mingo@kernel.org \
    --cc=mszeredi@redhat.com \
    --cc=paulmck@linux.vnet.ibm.com \
    --cc=torvalds@linux-foundation.org \
    --cc=viro@zeniv.linux.org.uk \
    --cc=wangkai86@huawei.com \
    --cc=willy@infradead.org \
    --subject='Re: [PATCH v3 0/4] fs/dcache: Track # of negative dentries' \
    /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

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).