Commit c2872d38 authored Mar 17, 2016 by Peter Zijlstra Committed by Ingo Molnar Mar 21, 2016

perf/x86/ibs: Add IBS interrupt to the dynamic throttle



Interrupt throttling is normally only done against
sysctl_perf_event_sample_rate. This means that if that number is too
high (for whatever reason) you can lock up your machine.

We have, however, a dynamic throttling scheme too, but for that to
work, we need to add a callback to the interrupt handler, IBS did not
have this, so add it.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

parent 5a50f529

arch/x86/events/amd/ibs.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -637,6 +637,7 @@ static int perf_ibs_handle_irq(struct perf_ibs perf_ibs, struct pt_regs iregs)
		static int
		perf_ibs_nmi_handler(unsigned int cmd, struct pt_regs *regs)
		{
		u64 stamp = sched_clock();
		int handled = 0;

		handled += perf_ibs_handle_irq(&perf_ibs_fetch, regs);
		@@ -645,6 +646,8 @@ perf_ibs_nmi_handler(unsigned int cmd, struct pt_regs *regs)
		if (handled)
		inc_irq_stat(apic_perf_irqs);

		perf_sample_event_took(sched_clock() - stamp);

		return handled;
		}
		NOKPROBE_SYMBOL(perf_ibs_nmi_handler);