From: tip-bot for Jason Baron <jbaron@redhat.com>
To: linux-tip-commits@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, gleb@redhat.com, hpa@zytor.com,
mingo@redhat.com, jbaron@redhat.com, tglx@linutronix.de,
mingo@elte.hu
Subject: [tip:perf/core] jump label: Add a WARN() if jump label key count goes negative
Date: Wed, 29 Feb 2012 02:13:40 -0800 [thread overview]
Message-ID: <tip-fadf0464b83f91ba021a358c0238a0810c0d2a0b@git.kernel.org> (raw)
In-Reply-To: <3c68556121be4d1920417a3fe367da1ec38246b4.1329851692.git.jbaron@redhat.com>
Commit-ID: fadf0464b83f91ba021a358c0238a0810c0d2a0b
Gitweb: http://git.kernel.org/tip/fadf0464b83f91ba021a358c0238a0810c0d2a0b
Author: Jason Baron <jbaron@redhat.com>
AuthorDate: Tue, 21 Feb 2012 15:02:53 -0500
Committer: Ingo Molnar <mingo@elte.hu>
CommitDate: Wed, 22 Feb 2012 07:59:39 +0100
jump label: Add a WARN() if jump label key count goes negative
The count on a jump label key should never go negative. Add a
WARN() to check for this condition.
Signed-off-by: Jason Baron <jbaron@redhat.com>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: rostedt@goodmis.org
Cc: mathieu.desnoyers@efficios.com
Cc: davem@davemloft.net
Cc: ddaney.cavm@gmail.com
Cc: a.p.zijlstra@chello.nl
Link: http://lkml.kernel.org/r/3c68556121be4d1920417a3fe367da1ec38246b4.1329851692.git.jbaron@redhat.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
kernel/jump_label.c | 5 ++++-
1 files changed, 4 insertions(+), 1 deletions(-)
diff --git a/kernel/jump_label.c b/kernel/jump_label.c
index 01d3b70..ed9654f 100644
--- a/kernel/jump_label.c
+++ b/kernel/jump_label.c
@@ -76,8 +76,11 @@ EXPORT_SYMBOL_GPL(jump_label_inc);
static void __jump_label_dec(struct jump_label_key *key,
unsigned long rate_limit, struct delayed_work *work)
{
- if (!atomic_dec_and_mutex_lock(&key->enabled, &jump_label_mutex))
+ if (!atomic_dec_and_mutex_lock(&key->enabled, &jump_label_mutex)) {
+ WARN(atomic_read(&key->enabled) < 0,
+ "jump label: negative count!\n");
return;
+ }
if (rate_limit) {
atomic_inc(&key->enabled);
next prev parent reply other threads:[~2012-02-29 10:14 UTC|newest]
Thread overview: 84+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-21 20:02 [PATCH 00/10] jump label: introduce very_[un]likely + cleanups + docs Jason Baron
2012-02-21 20:02 ` [PATCH 01/10] jump label: Add a WARN() if jump label key count goes negative Jason Baron
2012-02-29 10:13 ` tip-bot for Jason Baron [this message]
2012-02-21 20:02 ` [PATCH 02/10] jump label: fix compiler warning Jason Baron
2012-02-29 10:14 ` [tip:perf/core] jump label: Fix " tip-bot for Jason Baron
2012-02-21 20:03 ` [PATCH 03/10] jump label: introduce very_unlikely() Jason Baron
2012-02-21 20:03 ` [PATCH 04/10] jump label: introduce very_likely() Jason Baron
2012-02-21 20:03 ` [PATCH 05/10] perf: update to use 'very_unlikely()' Jason Baron
2012-02-21 20:03 ` [PATCH 06/10] tracepoints: update to use very_unlikely() Jason Baron
2012-02-21 20:03 ` [PATCH 07/10] sched: update to use very_[un]likely() Jason Baron
2012-02-21 20:03 ` [PATCH 08/10] kvm: update to use very_unlikely() Jason Baron
2012-02-21 20:03 ` [PATCH 09/10] net: " Jason Baron
2012-02-21 20:03 ` [PATCH 10/10] jump label: Add docs better explaining the whole jump label mechanism Jason Baron
2012-02-29 10:15 ` [tip:perf/core] static keys: Add docs better explaining the whole 'struct static_key' mechanism tip-bot for Jason Baron
2012-02-21 20:09 ` [PATCH 00/10] jump label: introduce very_[un]likely + cleanups + docs H. Peter Anvin
2012-02-21 20:20 ` Jason Baron
2012-02-21 20:39 ` Steven Rostedt
2012-02-21 21:10 ` H. Peter Anvin
2012-02-21 21:16 ` Mathieu Desnoyers
2012-02-21 21:11 ` Mathieu Desnoyers
2012-02-22 7:32 ` Ingo Molnar
2012-02-22 7:53 ` Ingo Molnar
2012-02-22 8:01 ` H. Peter Anvin
2012-02-22 8:18 ` Ingo Molnar
2012-02-22 8:58 ` [PATCH] static keys: Introduce 'struct static_key', very_[un]likely(), static_key_slow_[inc|dec]() Ingo Molnar
2012-02-29 10:16 ` [tip:perf/core] static keys: Introduce 'struct static_key', static_key_true()/false() and static_key_slow_[inc|dec]() tip-bot for Ingo Molnar
2012-02-22 9:03 ` [PATCH] jump labels: Explain the .config option better Ingo Molnar
2012-02-22 15:08 ` [PATCH 00/10] jump label: introduce very_[un]likely + cleanups + docs H. Peter Anvin
2012-02-22 15:51 ` Ingo Molnar
2012-02-22 21:33 ` Paul Mackerras
2012-02-23 10:02 ` Ingo Molnar
2012-02-23 16:21 ` Jason Baron
2012-02-23 17:10 ` H. Peter Anvin
2012-02-24 9:11 ` Ingo Molnar
2012-02-23 17:18 ` Linus Torvalds
2012-02-23 22:33 ` Ingo Molnar
2012-02-23 22:39 ` Ingo Molnar
2012-02-23 22:44 ` Steven Rostedt
2012-02-23 23:18 ` Mathieu Desnoyers
2012-02-24 2:25 ` Jason Baron
2012-02-24 9:08 ` Ingo Molnar
2012-02-24 15:35 ` Jason Baron
2012-02-27 7:40 ` Ingo Molnar
2012-02-24 15:51 ` Mathieu Desnoyers
2012-02-24 16:06 ` Steven Rostedt
2012-02-24 7:52 ` static keys: Introduce 'struct static_key', static_key_true()/false() and static_key_slow_[inc|dec]() Ingo Molnar
2012-02-24 7:59 ` [PATCH] " Ingo Molnar
2012-02-24 7:54 ` [PATCH] static keys: Add docs better explaining the whole 'struct static_key' mechanism Ingo Molnar
2012-02-23 22:45 ` [PATCH 00/10] jump label: introduce very_[un]likely + cleanups + docs Linus Torvalds
2012-02-24 8:04 ` Ingo Molnar
2012-02-24 2:42 ` Jason Baron
2012-02-21 20:21 ` Steven Rostedt
2012-02-21 21:11 ` H. Peter Anvin
2012-02-22 6:50 ` Ingo Molnar
2012-02-22 7:03 ` H. Peter Anvin
2012-02-22 7:25 ` Ingo Molnar
2012-02-22 7:35 ` H. Peter Anvin
2012-02-22 7:48 ` Ingo Molnar
2012-02-22 7:55 ` H. Peter Anvin
2012-02-22 8:06 ` Ingo Molnar
2012-02-22 13:22 ` Steven Rostedt
2012-02-22 13:34 ` Ingo Molnar
2012-02-22 13:54 ` Steven Rostedt
2012-02-22 14:20 ` Mathieu Desnoyers
2012-02-22 14:36 ` Steven Rostedt
2012-02-22 14:56 ` Ingo Molnar
2012-02-22 15:11 ` H. Peter Anvin
2012-02-22 15:11 ` Peter Zijlstra
2012-02-22 15:47 ` Ingo Molnar
2012-02-22 15:12 ` Steven Rostedt
2012-02-22 15:15 ` H. Peter Anvin
2012-02-22 15:19 ` H. Peter Anvin
2012-02-22 15:42 ` Jason Baron
2012-02-22 15:54 ` Steven Rostedt
2012-02-22 15:56 ` Jason Baron
2012-02-22 16:08 ` Steven Rostedt
2012-02-22 15:19 ` Jason Baron
2012-02-22 15:40 ` H. Peter Anvin
2012-02-22 15:13 ` Peter Zijlstra
2012-02-22 15:32 ` Peter Zijlstra
2012-02-22 17:14 ` Richard Henderson
2012-02-22 18:28 ` H. Peter Anvin
2012-02-22 18:58 ` Jason Baron
2012-02-22 19:10 ` H. Peter Anvin
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