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 3.18-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-3.18 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 @@ -1587,7 +1587,7 @@ 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-3.18/tracing-use-softirq_offset-for-softirq-dectection-for-more-accurate-results.patch