From: Waiman Long <longman@redhat.com>
To: Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>, Will Deacon <will.deacon@arm.com>
Cc: linux-kernel@vger.kernel.org, Waiman Long <longman@redhat.com>
Subject: [PATCH 0/5] locking/lockdep: Improve lockdep performance
Date: Fri, 28 Sep 2018 13:53:16 -0400 [thread overview]
Message-ID: <1538157201-29173-1-git-send-email-longman@redhat.com> (raw)
Enabling CONFIG_LOCKDEP and other related debug options will greatly
reduce system performance. This patchset aims to reduce the performance
slowdown caused by the lockdep code.
Patch 1 just removes an inline function that wasn't used.
Patches 2 and 3 are minor twists to optimize the code.
Patch 4 makes class->ops a per-cpu counter.
Patch 5 moves the lock_release() call outside of a lock critical section.
Parallel kernel compilation tests (make -j <#cpu>) were performed on
2 different systems:
1) an 1-socket 22-core 44-thread Skylake system
2) a 4-socket 72-core 144-thread Broadwell system
The build times with pre-patch and post-patch debug kernels were:
System Pre-patch Post-patch %Change
------ --------- ---------- -------
1-socket 8m53.9s 8m41.2s -2.4%
4-socket 7m27.0s 5m31.0s -26%
I think it is the last 2 patches that yield most of the performance
improvement.
Waiman Long (5):
locking/lockdep: Remove add_chain_cache_classes()
locking/lockdep: Eliminate redundant irqs check in __lock_acquire()
locking/lockdep: Add a faster path in __lock_release()
locking/lockdep: Make class->ops a percpu counter
locking/lockdep: Call lock_release after releasing the lock
include/linux/lockdep.h | 2 +-
include/linux/rwlock_api_smp.h | 16 +++---
include/linux/spinlock_api_smp.h | 8 +--
kernel/locking/lockdep.c | 120 ++++++++++++---------------------------
4 files changed, 48 insertions(+), 98 deletions(-)
--
1.8.3.1
next reply other threads:[~2018-09-28 17:53 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-28 17:53 Waiman Long [this message]
2018-09-28 17:53 ` [PATCH 1/5] locking/lockdep: Remove add_chain_cache_classes() Waiman Long
2018-09-28 17:53 ` [PATCH 2/5] locking/lockdep: Eliminate redundant irqs check in __lock_acquire() Waiman Long
2018-10-02 9:06 ` Ingo Molnar
2018-09-28 17:53 ` [PATCH 3/5] locking/lockdep: Add a faster path in __lock_release() Waiman Long
2018-10-02 9:03 ` Ingo Molnar
2018-09-28 17:53 ` [PATCH 4/5] locking/lockdep: Make class->ops a percpu counter Waiman Long
2018-09-28 20:25 ` kbuild test robot
2018-09-28 20:31 ` Waiman Long
2018-09-28 20:42 ` kbuild test robot
2018-10-02 9:39 ` Peter Zijlstra
2018-10-02 9:55 ` Ingo Molnar
2018-10-02 14:10 ` Waiman Long
2018-10-02 14:28 ` Peter Zijlstra
2018-10-02 18:53 ` Ingo Molnar
2018-09-28 17:53 ` [PATCH 5/5] locking/lockdep: Call lock_release after releasing the lock Waiman Long
2018-10-02 9:08 ` Ingo Molnar
2018-10-02 9:06 ` [PATCH 0/5] locking/lockdep: Improve lockdep performance Ingo Molnar
2018-10-02 13:57 ` 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=1538157201-29173-1-git-send-email-longman@redhat.com \
--to=longman@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--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).