This is a note to let you know that I've just added the patch titled
tracing: Use SOFTIRQ_OFFSET for softirq dectection for more accurate results
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
tracing-use-softirq_offset-for-softirq-dectection-for-more-accurate-results.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From c59f29cb144a6a0dfac16ede9dc8eafc02dc56ca Mon Sep 17 00:00:00 2001
From: Pavankumar Kondeti <pkondeti@xxxxxxxxxxxxxx>
Date: Fri, 9 Dec 2016 21:50:17 +0530
Subject: tracing: Use SOFTIRQ_OFFSET for softirq dectection for more accurate results
From: Pavankumar Kondeti <pkondeti@xxxxxxxxxxxxxx>
commit c59f29cb144a6a0dfac16ede9dc8eafc02dc56ca upstream.
The 's' flag is supposed to indicate that a softirq is running. This
can be detected by testing the preempt_count with SOFTIRQ_OFFSET.
The current code tests the preempt_count with SOFTIRQ_MASK, which
would be true even when softirqs are disabled but not serving a
softirq.
Link: http://lkml.kernel.org/r/1481300417-3564-1-git-send-email-pkondeti@xxxxxxxxxxxxxx
Signed-off-by: Pavankumar Kondeti <pkondeti@xxxxxxxxxxxxxx>
Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
Signed-off-by: Amit Pundir <amit.pundir@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
kernel/trace/trace.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1660,7 +1660,7 @@ tracing_generic_entry_update(struct trac
TRACE_FLAG_IRQS_NOSUPPORT |
#endif
((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) |
- ((pc & SOFTIRQ_MASK) ? TRACE_FLAG_SOFTIRQ : 0) |
+ ((pc & SOFTIRQ_OFFSET) ? TRACE_FLAG_SOFTIRQ : 0) |
(tif_need_resched() ? TRACE_FLAG_NEED_RESCHED : 0) |
(test_preempt_need_resched() ? TRACE_FLAG_PREEMPT_RESCHED : 0);
}
Patches currently in stable-queue which might be from pkondeti@xxxxxxxxxxxxxx are
queue-4.4/tracing-use-softirq_offset-for-softirq-dectection-for-more-accurate-results.patch