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authorThomas Gleixner <tglx@linutronix.de>2017-09-12 21:37:09 +0200
committerIngo Molnar <mingo@kernel.org>2017-09-14 11:41:06 +0200
commit0d85923c7a81719567311ba0eae8ecb2efd4c8a0 (patch)
tree34c854caa12350d56552dbae1545d6484a8d13c3 /kernel/watchdog.c
parent05ba3de74a3f499dcaa37b186220aaf174c95a4b (diff)
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smpboot/threads, watchdog/core: Avoid runtime allocation
smpboot_update_cpumask_threads_percpu() allocates a temporary cpumask at runtime. This is suboptimal because the call site needs more code size for proper error handling than a statically allocated temporary mask requires data size. Add static temporary cpumask. The function is globaly serialized, so no further protection required. Remove the half baken error handling in the watchdog code and get rid of the export as there are no in tree modular users of that function. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Don Zickus <dzickus@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sebastian Siewior <bigeasy@linutronix.de> Cc: Ulrich Obergfell <uobergfe@redhat.com> Link: http://lkml.kernel.org/r/20170912194147.297288838@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/watchdog.c')
-rw-r--r--kernel/watchdog.c21
1 files changed, 5 insertions, 16 deletions
diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index cedf45ab4d81..8935a3a4c2fb 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -787,31 +787,20 @@ out:
return err;
}
-static int watchdog_update_cpus(void)
+static void watchdog_update_cpus(void)
{
- if (IS_ENABLED(CONFIG_SOFTLOCKUP_DETECTOR)) {
- return smpboot_update_cpumask_percpu_thread(&watchdog_threads,
- &watchdog_cpumask);
+ if (IS_ENABLED(CONFIG_SOFTLOCKUP_DETECTOR) && watchdog_running) {
+ smpboot_update_cpumask_percpu_thread(&watchdog_threads,
+ &watchdog_cpumask);
__lockup_detector_cleanup();
}
- return 0;
}
static void proc_watchdog_cpumask_update(void)
{
/* Remove impossible cpus to keep sysctl output clean. */
cpumask_and(&watchdog_cpumask, &watchdog_cpumask, cpu_possible_mask);
-
- if (watchdog_running) {
- /*
- * Failure would be due to being unable to allocate a
- * temporary cpumask, so we are likely not in a position to
- * do much else to make things better.
- */
- if (watchdog_update_cpus() != 0)
- pr_err("cpumask update failed\n");
- }
-
+ watchdog_update_cpus();
watchdog_nmi_reconfigure();
}