From: Mark Brown <broonie@kernel.org>
To: Davidlohr Bueso <dave@stgolabs.net>
Cc: akpm@linux-foundation.org, linux-kernel@vger.kernel.org,
mcgrof@kernel.org, alex.williamson@redhat.com,
Davidlohr Bueso <dbueso@suse.de>
Subject: Re: [PATCH 3/5] regmap: optimize sync() and drop() regcache callbacks
Date: Mon, 10 Feb 2020 13:11:57 +0000 [thread overview]
Message-ID: <20200210131157.GE7685@sirena.org.uk> (raw)
In-Reply-To: <20200207180305.11092-4-dave@stgolabs.net>
[-- Attachment #1: Type: text/plain, Size: 793 bytes --]
On Fri, Feb 07, 2020 at 10:03:03AM -0800, Davidlohr Bueso wrote:
> At a higher memory footprint (two additional pointers per node) we
> can get branchless O(1) tree iterators which can optimize in-order
> tree walks/traversals. For example, on my laptop looking at the rbtree
> debugfs entries:
It's not clear that this is a good optimization - we're increasing the
memory footprint for a bit of performance but our performance is all
relative to the I2C or SPI I/O we're most likely all in the noise here
whereas for larger maps the size cost looks like it could be quite bad
(but equally your case looks to have a lot of 2 register blocks which is
almost the worst case for overhead so...).
That said the code is fine so from that point of view:
Acked-by: Mark Brown <broonie@kernel.org>
[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 488 bytes --]
next prev parent reply other threads:[~2020-02-10 13:12 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-07 18:03 [PATCH -next 0/5] rbtree: optimize frequent tree walks Davidlohr Bueso
2020-02-07 18:03 ` [PATCH 1/5] lib/rbtree: introduce linked-list rbtree interface Davidlohr Bueso
2020-02-10 20:07 ` Luis Chamberlain
2020-02-10 21:28 ` Davidlohr Bueso
2020-02-10 21:44 ` Luis Chamberlain
2020-02-07 18:03 ` [PATCH 2/5] proc/sysctl: optimize proc_sys_readdir Davidlohr Bueso
2020-02-10 20:08 ` Luis Chamberlain
2020-02-07 18:03 ` [PATCH 3/5] regmap: optimize sync() and drop() regcache callbacks Davidlohr Bueso
2020-02-10 13:11 ` Mark Brown [this message]
2020-02-07 18:03 ` [PATCH 4/5] vfio/type1: optimize dma_list tree iterations Davidlohr Bueso
2020-02-07 18:03 ` [PATCH 5/5] uprobes: optimize build_probe_list() Davidlohr Bueso
2020-02-10 1:46 ` [PATCH -next 0/5] rbtree: optimize frequent tree walks Andrew Morton
2020-02-10 15:56 ` Davidlohr Bueso
2020-02-10 22:35 ` Andrew Morton
2020-02-13 15:50 ` Davidlohr Bueso
2020-02-11 11:20 ` Mark Brown
2020-02-13 15:55 ` Davidlohr Bueso
2020-02-13 16:56 ` Mark Brown
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=20200210131157.GE7685@sirena.org.uk \
--to=broonie@kernel.org \
--cc=akpm@linux-foundation.org \
--cc=alex.williamson@redhat.com \
--cc=dave@stgolabs.net \
--cc=dbueso@suse.de \
--cc=linux-kernel@vger.kernel.org \
--cc=mcgrof@kernel.org \
/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
all inboxes | Powered by JetHome®