linux-kernel - [tip:sched/core] sched/isolation: Provide a dynamic off-case to housekeeping_any

lists.openwall.net		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 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <tip-9f0ca2d97ef0b5e966be2cfef26c7c094ec14e41@git.kernel.org>
Date:   Fri, 27 Oct 2017 05:02:37 -0700
From:   tip-bot for Frederic Weisbecker <tipbot@...or.com>
To:     linux-tip-commits@...r.kernel.org
Cc:     paulmck@...ux.vnet.ibm.com, peterz@...radead.org,
        kernellwp@...il.com, cmetcalf@...lanox.com, riel@...hat.com,
        tglx@...utronix.de, torvalds@...ux-foundation.org, cl@...ux.com,
        efault@....de, linux-kernel@...r.kernel.org, mingo@...nel.org,
        frederic@...nel.org, lcapitulino@...hat.com, hpa@...or.com
Subject: [tip:sched/core] sched/isolation: Provide a dynamic off-case to
 housekeeping_any_cpu()

Commit-ID:  9f0ca2d97ef0b5e966be2cfef26c7c094ec14e41
Gitweb:     https://git.kernel.org/tip/9f0ca2d97ef0b5e966be2cfef26c7c094ec14e41
Author:     Frederic Weisbecker <frederic@...nel.org>
AuthorDate: Fri, 27 Oct 2017 04:42:30 +0200
Committer:  Ingo Molnar <mingo@...nel.org>
CommitDate: Fri, 27 Oct 2017 09:55:26 +0200

sched/isolation: Provide a dynamic off-case to housekeeping_any_cpu()

housekeeping_any_cpu() doesn't handle correctly the case where
CONFIG_NO_HZ_FULL=y and no CPU is in nohz_full mode. So far no caller
needs this but let's prepare to avoid any future surprise.

Signed-off-by: Frederic Weisbecker <frederic@...nel.org>
Acked-by: Thomas Gleixner <tglx@...utronix.de>
Cc: Chris Metcalf <cmetcalf@...lanox.com>
Cc: Christoph Lameter <cl@...ux.com>
Cc: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Luiz Capitulino <lcapitulino@...hat.com>
Cc: Mike Galbraith <efault@....de>
Cc: Paul E. McKenney <paulmck@...ux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@...radead.org>
Cc: Rik van Riel <riel@...hat.com>
Cc: Wanpeng Li <kernellwp@...il.com>
Link: http://lkml.kernel.org/r/1509072159-31808-4-git-send-email-frederic@kernel.org
Signed-off-by: Ingo Molnar <mingo@...nel.org>
---
 include/linux/sched/isolation.h | 17 ++++++-----------
 1 file changed, 6 insertions(+), 11 deletions(-)

diff --git a/include/linux/sched/isolation.h b/include/linux/sched/isolation.h
index b7cfbc4..040df04 100644
--- a/include/linux/sched/isolation.h
+++ b/include/linux/sched/isolation.h
@@ -7,25 +7,20 @@
 
 #ifdef CONFIG_NO_HZ_FULL
 extern cpumask_var_t housekeeping_mask;
-
-static inline int housekeeping_any_cpu(void)
-{
-	return cpumask_any_and(housekeeping_mask, cpu_online_mask);
-}
-
 extern void __init housekeeping_init(void);
-
 #else
+static inline void housekeeping_init(void) { }
+#endif /* CONFIG_NO_HZ_FULL */
 
 static inline int housekeeping_any_cpu(void)
 {
+#ifdef CONFIG_NO_HZ_FULL
+	if (tick_nohz_full_enabled())
+		return cpumask_any_and(housekeeping_mask, cpu_online_mask);
+#endif
 	return smp_processor_id();
 }
 
-static inline void housekeeping_init(void) { }
-#endif /* CONFIG_NO_HZ_FULL */
-
-
 static inline const struct cpumask *housekeeping_cpumask(void)
 {
 #ifdef CONFIG_NO_HZ_FULL