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authorLinus Torvalds <torvalds@linux-foundation.org>2019-02-03 17:59:51 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2019-02-03 17:59:51 +0100
commit58f6d4287af751a75b24f4d32e6e1b077146ab18 (patch)
treee6bf85d9645dc1a0e54ef30d02cee65d0507e339 /kernel
parentMerge branch 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/ker... (diff)
parentMerge tag 'perf-urgent-for-mingo-5.0-20190121' of git://git.kernel.org/pub/sc... (diff)
downloadlinux-58f6d4287af751a75b24f4d32e6e1b077146ab18.tar.xz
linux-58f6d4287af751a75b24f4d32e6e1b077146ab18.zip
Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Thomas Gleixner: "A pile of perf updates: - Fix broken sanity check in the /proc/sys/kernel/perf_cpu_time_max_percent write handler - Cure a perf script crash which caused by an unitinialized data structure - Highlight the hottest instruction in perf top and not a random one - Cure yet another clang issue when building perf python - Handle topology entries with no CPU correctly in the tools - Handle perf data which contains both tracepoints and performance counter entries correctly. - Add a missing NULL pointer check in perf ordered_events_free()" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf script: Fix crash when processing recorded stat data perf top: Fix wrong hottest instruction highlighted perf tools: Handle TOPOLOGY headers with no CPU perf python: Remove -fstack-clash-protection when building with some clang versions perf core: Fix perf_proc_update_handler() bug perf script: Fix crash with printing mixed trace point and other events perf ordered_events: Fix crash in ordered_events__free
Diffstat (limited to 'kernel')
-rw-r--r--kernel/events/core.c14
1 files changed, 7 insertions, 7 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 3cd13a30f732..e5ede6918050 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -436,18 +436,18 @@ int perf_proc_update_handler(struct ctl_table *table, int write,
void __user *buffer, size_t *lenp,
loff_t *ppos)
{
- int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
-
- if (ret || !write)
- return ret;
-
+ int ret;
+ int perf_cpu = sysctl_perf_cpu_time_max_percent;
/*
* If throttling is disabled don't allow the write:
*/
- if (sysctl_perf_cpu_time_max_percent == 100 ||
- sysctl_perf_cpu_time_max_percent == 0)
+ if (write && (perf_cpu == 100 || perf_cpu == 0))
return -EINVAL;
+ ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
+ if (ret || !write)
+ return ret;
+
max_samples_per_tick = DIV_ROUND_UP(sysctl_perf_event_sample_rate, HZ);
perf_sample_period_ns = NSEC_PER_SEC / sysctl_perf_event_sample_rate;
update_perf_cpu_limits();