From: Waiman Long <waiman.long@hpe.com>
To: Tejun Heo <tj@kernel.org>
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: Tue, 12 Apr 2016 14:15:22 -0400 [thread overview]
Message-ID: <570D3B3A.8080204@hpe.com> (raw)
In-Reply-To: <20160411221700.GP24661@htj.duckdns.org>
On 04/11/2016 06:17 PM, Tejun Heo wrote:
> 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.
>
I have updated my patch to use percpu_counter instead. Thanks for all
the comments and review so far.
Cheers,
Longman
next prev parent reply other threads:[~2016-04-12 18:15 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
2016-04-12 18:15 ` Waiman Long [this message]
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=570D3B3A.8080204@hpe.com \
--to=waiman.long@hpe.com \
--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=tj@kernel.org \
--cc=toshi.kani@hpe.com \
--cc=tytso@mit.edu \
/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.