mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: Frederic Weisbecker <fweisbec@gmail.com>
To: Ingo Molnar <mingo@elte.hu>
Cc: LKML <linux-kernel@vger.kernel.org>,
	Frederic Weisbecker <fweisbec@gmail.com>,
	"2 . 6 . 33 . x" <stable@kernel.org>,
	Peter Zijlstra <a.p.zijlstra@chello.nl>,
	"K . Prasad" <prasad@linux.vnet.ibm.com>,
	Paul Mackerras <paulus@samba.org>
Subject: [GIT PULL] hw-breakpoint fix
Date: Sun, 28 Feb 2010 21:53:36 +0100	[thread overview]
Message-ID: <1267390416-8756-1-git-send-regression-fweisbec@gmail.com> (raw)

Ingo,

Please pull the perf/urgent branch that can be found at:

git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing.git
	perf/urgent

Thanks,
	Frederic
---

Frederic Weisbecker (1):
      hw-breakpoints: Remove stub unthrottle callback


 arch/x86/kernel/hw_breakpoint.c |    5 -----
 kernel/hw_breakpoint.c          |    1 -
 2 files changed, 0 insertions(+), 6 deletions(-)

---
commit 1e259e0a9982078896f3404240096cbea01daca4
Author: Frederic Weisbecker <fweisbec@gmail.com>
Date:   Sun Feb 28 20:51:15 2010 +0100

    hw-breakpoints: Remove stub unthrottle callback
    
    We support event unthrottling in breakpoint events. It means
    that if we have more than sysctl_perf_event_sample_rate/HZ,
    perf will throttle, ignoring subsequent events until the next
    tick.
    
    So if ptrace exceeds this max rate, it will omit events, which
    breaks the ptrace determinism that is supposed to report every
    triggered breakpoints. This is likely to happen if we set
    sysctl_perf_event_sample_rate to 1.
    
    This patch removes support for unthrottling in breakpoint
    events to break throttling and restore ptrace determinism.
    
    Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
    Cc: 2.6.33.x <stable@kernel.org>
    Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
    Cc: K.Prasad <prasad@linux.vnet.ibm.com>
    Cc: Paul Mackerras <paulus@samba.org>

diff --git a/arch/x86/kernel/hw_breakpoint.c b/arch/x86/kernel/hw_breakpoint.c
index bb6006e..1e8cead 100644
--- a/arch/x86/kernel/hw_breakpoint.c
+++ b/arch/x86/kernel/hw_breakpoint.c
@@ -531,8 +531,3 @@ void hw_breakpoint_pmu_read(struct perf_event *bp)
 {
 	/* TODO */
 }
-
-void hw_breakpoint_pmu_unthrottle(struct perf_event *bp)
-{
-	/* TODO */
-}
diff --git a/kernel/hw_breakpoint.c b/kernel/hw_breakpoint.c
index 967e661..4d99512 100644
--- a/kernel/hw_breakpoint.c
+++ b/kernel/hw_breakpoint.c
@@ -489,5 +489,4 @@ struct pmu perf_ops_bp = {
 	.enable		= arch_install_hw_breakpoint,
 	.disable	= arch_uninstall_hw_breakpoint,
 	.read		= hw_breakpoint_pmu_read,
-	.unthrottle	= hw_breakpoint_pmu_unthrottle
 };

             reply	other threads:[~2010-02-28 20:53 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-02-28 20:53 Frederic Weisbecker [this message]
  -- strict thread matches above, loose matches on Subject: below --
2010-02-04  1:46 Frederic Weisbecker
2010-02-11 11:12 ` Mahesh Jagannath Salgaonkar
2010-02-11 14:49   ` Frederic Weisbecker

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=1267390416-8756-1-git-send-regression-fweisbec@gmail.com \
    --to=fweisbec@gmail.com \
    --cc=a.p.zijlstra@chello.nl \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@elte.hu \
    --cc=paulus@samba.org \
    --cc=prasad@linux.vnet.ibm.com \
    --cc=stable@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

Powered by JetHome