From: Tejun Heo <tj@kernel.org>
To: Waiman Long <waiman.long@hpe.com>
Cc: Theodore Ts'o <tytso@mit.edu>,
Andreas Dilger <adilger.kernel@dilger.ca>,
Christoph Lameter <cl@linux.com>,
linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org,
Scott J Norton <scott.norton@hpe.com>,
Douglas Hatch <doug.hatch@hpe.com>,
Toshimitsu Kani <toshi.kani@hpe.com>
Subject: Re: [PATCH v2 2/4] percpu_stats: Enable 64-bit counts in 32-bit architectures
Date: Mon, 11 Apr 2016 18:17:00 -0400 [thread overview]
Message-ID: <20160411221700.GP24661@htj.duckdns.org> (raw)
In-Reply-To: <5707FC52.3070707@hpe.com>
Hello, Waiman.
On Fri, Apr 08, 2016 at 02:45:38PM -0400, Waiman Long wrote:
> The percpu_stats construct allows minimal overhead in maintaining statistics
> counts. The percpu_counter construct, on the other hand, has a higher
> performance overhead and a bit more complex to set up and tear down when
If you're referring to the preemption on/off, as I wrote before, we'll
probably be able to improve that with this_cpu_add_return so that the
only extra overhead is an easily predictable branch which is extremely
cheap. It's better to improve common constructs anyway.
> more than one statistics counts are needed. In fact, my first draft of the
And yeah, it can be cumbersome to set up and tear down multiple
percpu_counters. If there are enough consumers, we can extend
percpu_counter to handle multiple counters, right?
Thanks.
--
tejun
next prev parent reply other threads:[~2016-04-11 22:17 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-08 16:16 [PATCH v2 0/4] ext4: Improve parallel I/O performance on NVDIMM Waiman Long
2016-04-08 16:16 ` [PATCH v2 1/4] percpu_stats: Simple per-cpu statistics count helper functions Waiman Long
2016-04-08 16:49 ` kbuild test robot
2016-04-08 17:45 ` kbuild test robot
2016-04-08 16:16 ` [PATCH v2 2/4] percpu_stats: Enable 64-bit counts in 32-bit architectures Waiman Long
2016-04-08 16:47 ` Tejun Heo
2016-04-08 17:32 ` Waiman Long
2016-04-08 17:46 ` Tejun Heo
2016-04-08 18:45 ` Waiman Long
2016-04-11 22:17 ` Tejun Heo [this message]
2016-04-12 18:15 ` Waiman Long
2016-04-08 16:16 ` [PATCH v2 3/4] ext4: Pass in DIO_SKIP_DIO_COUNT flag if inode_dio_begin() called Waiman Long
2016-04-08 16:16 ` [PATCH v2 4/4] ext4: Make cache hits/misses per-cpu counts 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=20160411221700.GP24661@htj.duckdns.org \
--to=tj@kernel.org \
--cc=adilger.kernel@dilger.ca \
--cc=cl@linux.com \
--cc=doug.hatch@hpe.com \
--cc=linux-ext4@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=scott.norton@hpe.com \
--cc=toshi.kani@hpe.com \
--cc=tytso@mit.edu \
--cc=waiman.long@hpe.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).