From: Catalin Marinas <catalin.marinas@arm.com>
To: Will Deacon <will.deacon@arm.com>
Cc: linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, corbet@lwn.net,
peterz@infradead.org, jbaron@akamai.com, Suzuki.Poulose@arm.com
Subject: [PATCH v2 0/2] arm64: Use static keys for CPU features
Date: Mon, 5 Sep 2016 18:25:46 +0100 [thread overview]
Message-ID: <1473096348-19548-1-git-send-email-catalin.marinas@arm.com> (raw)
This series is aimed at optimising the arm64 cpus_have_cap()
functionality (checking for the presence of certain CPU
capabilities/features) to avoid a bitmap test and use a jump label
instead, patched at boot time.
While this series does not provide a significant performance improvement
with the current kernel, it will be more beneficial with new features
like TTBR0 PAN are which are used on hot paths (get_user/put_user,
thread switching).
Jon, if you are happy with this patch (especially the documentation
update), are ok for it to go into mainline via the arm64 tree?
While there doesn't seem to be a specific maintainer for jump_label.*,
cc'ing Peter and Jason for comments/acks/naks.
Thanks.
Changes since v1:
- Moved the jump_label_init() call to smp_prepare_boot_cpu() following
Suzuki's suggestion
- Fixed missing empty line in Documentation/static-keys.txt
Catalin Marinas (2):
jump_labels: Allow array initialisers
arm64: Use static keys for CPU features
Documentation/static-keys.txt | 9 +++++++++
arch/arm64/include/asm/cpufeature.h | 14 +++++++++++---
arch/arm64/kernel/cpufeature.c | 3 +++
arch/arm64/kernel/smp.c | 5 +++++
include/linux/jump_label.h | 12 ++++++++++++
5 files changed, 40 insertions(+), 3 deletions(-)
next reply other threads:[~2016-09-05 17:26 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-05 17:25 Catalin Marinas [this message]
2016-09-05 17:25 ` [PATCH v2 1/2] jump_labels: Allow array initialisers Catalin Marinas
2016-09-06 18:11 ` Will Deacon
2016-09-06 18:50 ` Peter Zijlstra
2016-09-05 17:25 ` [PATCH v2 2/2] arm64: Use static keys for CPU features Catalin Marinas
2016-09-07 16:59 ` Jason Baron
2016-09-08 13:40 ` Catalin Marinas
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=1473096348-19548-1-git-send-email-catalin.marinas@arm.com \
--to=catalin.marinas@arm.com \
--cc=Suzuki.Poulose@arm.com \
--cc=corbet@lwn.net \
--cc=jbaron@akamai.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=peterz@infradead.org \
--cc=will.deacon@arm.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).