From: Peter Zijlstra <peterz@infradead.org> To: mingo@kernel.org, tglx@linutronix.de, rostedt@goodmis.org Cc: linux-kernel@vger.kernel.org, kan.liang@linux.intel.com, acme@kernel.org, mark.rutland@arm.com, alexander.shishkin@linux.intel.com, jolsa@redhat.com, namhyung@kernel.org, ak@linux.intel.com, eranian@google.com, peterz@infradead.org, Jesper Dangaard Brouer <brouer@redhat.com> Subject: [PATCH 4/6] perf: Optimize get_recursion_context() Date: Fri, 30 Oct 2020 16:13:49 +0100 Message-ID: <20201030151955.187580298@infradead.org> (raw) In-Reply-To: <20201030151345.540479897@infradead.org> "Look ma, no branches!" Cc: Jesper Dangaard Brouer <brouer@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> --- kernel/events/internal.h | 17 ++++++++--------- 1 file changed, 8 insertions(+), 9 deletions(-) --- a/kernel/events/internal.h +++ b/kernel/events/internal.h @@ -205,16 +205,15 @@ DEFINE_OUTPUT_COPY(__output_copy_user, a static inline int get_recursion_context(int *recursion) { - int rctx; + unsigned int pc = preempt_count(); + unsigned int rctx = 0; - if (unlikely(in_nmi())) - rctx = 3; - else if (in_irq()) - rctx = 2; - else if (in_serving_softirq()) - rctx = 1; - else - rctx = 0; + if (pc & (NMI_MASK)) + rctx++; + if (pc & (NMI_MASK | HARDIRQ_MASK)) + rctx++; + if (pc & (NMI_MASK | HARDIRQ_MASK | SOFTIRQ_OFFSET)) + rctx++; if (recursion[rctx]) return -1;
next prev parent reply index Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-10-30 15:13 [PATCH 0/6] perf: Reduce stack usage (and misc bits) Peter Zijlstra 2020-10-30 15:13 ` [PATCH 1/6] perf: Reduce stack usage of perf_output_begin() Peter Zijlstra 2020-11-10 12:45 ` [tip: perf/urgent] " tip-bot2 for Peter Zijlstra 2020-10-30 15:13 ` [PATCH 2/6] perf/x86: Reduce stack usage for x86_pmu::drain_pebs() Peter Zijlstra 2020-11-10 12:45 ` [tip: perf/urgent] " tip-bot2 for Peter Zijlstra 2020-10-30 15:13 ` [PATCH 3/6] perf: Fix get_recursion_context() Peter Zijlstra 2020-11-10 12:45 ` [tip: perf/urgent] " tip-bot2 for Peter Zijlstra 2020-10-30 15:13 ` Peter Zijlstra [this message] 2020-10-30 17:11 ` [PATCH 4/6] perf: Optimize get_recursion_context() Jesper Dangaard Brouer 2020-10-30 20:22 ` Steven Rostedt 2020-10-30 22:14 ` Thomas Gleixner 2020-10-30 23:31 ` Steven Rostedt 2020-10-31 11:23 ` Peter Zijlstra 2020-10-30 23:01 ` Peter Zijlstra 2020-10-31 12:11 ` David Laight 2020-10-31 13:18 ` David Laight 2020-11-09 12:12 ` Peter Zijlstra 2020-11-09 14:14 ` David Laight 2020-11-10 12:45 ` [tip: perf/urgent] " tip-bot2 for Peter Zijlstra 2020-10-30 15:13 ` [PATCH 5/6] perf/arch: Remove perf_sample_data::regs_user_copy Peter Zijlstra 2020-11-10 12:45 ` [tip: perf/urgent] " tip-bot2 for Peter Zijlstra 2020-10-30 15:13 ` [PATCH 6/6] perf/x86: Make dummy_iregs static Peter Zijlstra 2020-11-10 12:45 ` [tip: perf/urgent] " tip-bot2 for Peter Zijlstra
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