All of lore.kernel.org
 help / color / mirror / Atom feed
From: tip-bot for Ingo Molnar <tipbot@zytor.com>
To: linux-tip-commits@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, tglx@linutronix.de,
	peterz@infradead.org, tony@atomide.com, hpa@zytor.com,
	torvalds@linux-foundation.org, mingo@kernel.org,
	byungchul.park@lge.com, arnd@arndb.de, johan@kernel.org
Subject: [tip:locking/urgent] locking/lockdep: Disable cross-release features for now
Date: Sat, 14 Oct 2017 04:36:51 -0700	[thread overview]
Message-ID: <tip-b483cf3bc249d7af706390efa63d6671e80d1c09@git.kernel.org> (raw)
In-Reply-To: <20171014072659.f2yr6mhm5ha3eou7@gmail.com>

Commit-ID:  b483cf3bc249d7af706390efa63d6671e80d1c09
Gitweb:     https://git.kernel.org/tip/b483cf3bc249d7af706390efa63d6671e80d1c09
Author:     Ingo Molnar <mingo@kernel.org>
AuthorDate: Sat, 14 Oct 2017 09:26:59 +0200
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Sat, 14 Oct 2017 12:50:26 +0200

locking/lockdep: Disable cross-release features for now

Johan Hovold reported a big lockdep slowdown on his system, caused by lockdep:

> I had noticed that the BeagleBone Black boot time appeared to have
> increased significantly with 4.14 and yesterday I finally had time to
> investigate it.
>
> Boot time (from "Linux version" to login prompt) had in fact doubled
> since 4.13 where it took 17 seconds (with my current config) compared to
> the 35 seconds I now see with 4.14-rc4.
>
> I quick bisect pointed to lockdep and specifically the following commit:
>
>	28a903f63ec0 ("locking/lockdep: Handle non(or multi)-acquisition of a crosslock")

Because the final v4.14 release is close, disable the cross-release lockdep
features for now.

Bisected-by: Johan Hovold <johan@kernel.org>
Debugged-by: Johan Hovold <johan@kernel.org>
Reported-by: Johan Hovold <johan@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Byungchul Park <byungchul.park@lge.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Lindgren <tony@atomide.com>
Cc: kernel-team@lge.com
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-mm@kvack.org
Cc: linux-omap@vger.kernel.org
Link: http://lkml.kernel.org/r/20171014072659.f2yr6mhm5ha3eou7@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 lib/Kconfig.debug | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 2689b7c..e270584 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1092,8 +1092,8 @@ config PROVE_LOCKING
 	select DEBUG_MUTEXES
 	select DEBUG_RT_MUTEXES if RT_MUTEXES
 	select DEBUG_LOCK_ALLOC
-	select LOCKDEP_CROSSRELEASE
-	select LOCKDEP_COMPLETIONS
+	select LOCKDEP_CROSSRELEASE if BROKEN
+	select LOCKDEP_COMPLETIONS if BROKEN
 	select TRACE_IRQFLAGS
 	default n
 	help

  parent reply	other threads:[~2017-10-14 11:40 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-10-13  9:03 Dramatic lockdep slowdown in 4.14 Johan Hovold
2017-10-13  9:03 ` Johan Hovold
2017-10-13  9:03 ` Johan Hovold
2017-10-13  9:07 ` Peter Zijlstra
2017-10-13  9:07   ` Peter Zijlstra
2017-10-13  9:07   ` Peter Zijlstra
2017-10-13  9:35   ` Johan Hovold
2017-10-13  9:35     ` Johan Hovold
2017-10-13  9:35     ` Johan Hovold
2017-10-14  7:26 ` Ingo Molnar
2017-10-14  7:26   ` Ingo Molnar
2017-10-14  7:26   ` Ingo Molnar
2017-10-14  8:11   ` Johan Hovold
2017-10-14  8:11     ` Johan Hovold
2017-10-14  8:11     ` Johan Hovold
2017-10-14 11:36   ` tip-bot for Ingo Molnar [this message]
2017-10-16  2:04     ` [tip:locking/urgent] locking/lockdep: Disable cross-release features for now Byungchul Park
2017-10-17  7:12       ` Ingo Molnar
2017-10-17  7:40         ` Thomas Gleixner
2017-10-17 14:42           ` Ingo Molnar
2017-10-17 15:03             ` Thomas Gleixner
2017-10-17 16:21               ` Ingo Molnar
2017-10-18  7:48               ` Byungchul Park
2017-10-18  5:31         ` Byungchul Park

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=tip-b483cf3bc249d7af706390efa63d6671e80d1c09@git.kernel.org \
    --to=tipbot@zytor.com \
    --cc=arnd@arndb.de \
    --cc=byungchul.park@lge.com \
    --cc=hpa@zytor.com \
    --cc=johan@kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-tip-commits@vger.kernel.org \
    --cc=mingo@kernel.org \
    --cc=peterz@infradead.org \
    --cc=tglx@linutronix.de \
    --cc=tony@atomide.com \
    --cc=torvalds@linux-foundation.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 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.