lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Date:	Wed, 3 Jun 2015 17:56:24 -0700
From:	Jeremiah Mahler <>
To:	Thomas Gleixner <>
Cc:	Preeti U Murthy <>,
	Peter Zijlstra <>,
	Viresh Kumar <>,
	Marcelo Tosatti <>,
	Frederic Weisbecker <>,
	John Stultz <>,
Subject: [BUG, bisect] hrtimer: severe lag after suspend & resume


After a fresh boot, the Chrome web browser behaves normally.  Pages
load quickly and scroll fast.  Even image heavy sites such as work fine.  However, after a suspend and resume
cycle, Chrome becomes very slow.  Pages take ten seconds or more to
load.  The scroll bars and buttons are almost completely
unresponsive.  Interestingly, I can run Firefox on the same sites
and it has no issue whatsoever.

I have bisected the kernel and found that the following commit
introduced the bug.  It is present in the latest linux-next (20150602).

  From 868a3e915f7f5eba8f8cb4f7da2276760807c51c Mon Sep 17 00:00:00 2001
  From: Thomas Gleixner <>
  Date: Tue, 14 Apr 2015 21:08:37 +0000
  Subject: [PATCH] hrtimer: Make offset update smarter
  On every tick/hrtimer interrupt we update the offset variables of the
  clock bases. That's silly because these offsets change very seldom.
  Add a sequence counter to the time keeping code which keeps track of
  the offset updates (clock_was_set()). Have a sequence cache in the
  hrtimer cpu bases to evaluate whether the offsets must be updated or
  not. This allows us later to avoid pointless cacheline pollution.
  Signed-off-by: Thomas Gleixner <>
  Reviewed-by: Preeti U Murthy <>
  Acked-by: Peter Zijlstra <>
  Cc: Viresh Kumar <>
  Cc: Marcelo Tosatti <>
  Cc: Frederic Weisbecker <>
  Cc: John Stultz <>
  Signed-off-by: Thomas Gleixner <>
  Cc: John Stultz <>
   include/linux/hrtimer.h             |  4 ++--
   include/linux/timekeeper_internal.h |  2 ++
   kernel/time/hrtimer.c               |  3 ++-
   kernel/time/timekeeping.c           | 23 ++++++++++++++++-------
   kernel/time/timekeeping.h           |  7 ++++---
   5 files changed, 26 insertions(+), 13 deletions(-)

- Jeremiah Mahler
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

Powered by blists - more mailing lists