The patch titled
Subject: tracing-mm-dont-trace-mm_page_pcpu_drain-on-offline-cpus-fix
has been added to the -mm tree. Its filename is
tracing-mm-dont-trace-mm_page_pcpu_drain-on-offline-cpus-fix.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/tracing-mm-dont-trace-mm_page_pcpu_drain-on-offline-cpus-fix.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/tracing-mm-dont-trace-mm_page_pcpu_drain-on-offline-cpus-fix.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: "Shreyas B. Prabhu" <shreyas@xxxxxxxxxxxxxxxxxx>
Subject: tracing-mm-dont-trace-mm_page_pcpu_drain-on-offline-cpus-fix
use raw_smp_processor_id()
Cc: Preeti U Murthy <preeti@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/trace/events/kmem.h | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff -puN include/trace/events/kmem.h~tracing-mm-dont-trace-mm_page_pcpu_drain-on-offline-cpus-fix include/trace/events/kmem.h
--- a/include/trace/events/kmem.h~tracing-mm-dont-trace-mm_page_pcpu_drain-on-offline-cpus-fix
+++ a/include/trace/events/kmem.h
@@ -282,7 +282,16 @@ TRACE_EVENT_CONDITION(mm_page_pcpu_drain
TP_ARGS(page, order, migratetype),
- TP_CONDITION(cpu_online(smp_processor_id())),
+ /*
+ * This trace can be potentially called from an offlined cpu.
+ * Since trace points use RCU and RCU should not be used from
+ * offline cpus, filter such calls out.
+ * While this trace can be called from a preemptable section,
+ * it has no impact on the condition since tasks can migrate
+ * only from online cpus to other online cpus. Thus its safe
+ * to use raw_smp_processor_id.
+ */
+ TP_CONDITION(cpu_online(raw_smp_processor_id())),
TP_STRUCT__entry(
__field( unsigned long, pfn )
_
Patches currently in -mm which might be from shreyas@xxxxxxxxxxxxxxxxxx are
tracing-mm-dont-trace-kmem_cache_free-on-offline-cpus.patch
tracing-mm-dont-trace-kmem_cache_free-on-offline-cpus-fix.patch
tracing-mm-dont-trace-mm_page_free-on-offline-cpus.patch
tracing-mm-dont-trace-mm_page_free-on-offline-cpus-fix.patch
tracing-mm-dont-trace-mm_page_pcpu_drain-on-offline-cpus.patch
tracing-mm-dont-trace-mm_page_pcpu_drain-on-offline-cpus-fix.patch
a.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
