Messages in this thread | | | Subject | Re: [RFC][PATCH 7/7] perf: Optimize sw events | From | Peter Zijlstra <> | Date | Fri, 15 Oct 2010 16:57:07 +0200 |
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On Fri, 2010-10-15 at 11:16 +0200, Peter Zijlstra wrote: > On Thu, 2010-10-14 at 22:34 +0200, Peter Zijlstra wrote: > > > Index: linux-2.6/include/linux/perf_event.h > > =================================================================== > > --- linux-2.6.orig/include/linux/perf_event.h > > +++ linux-2.6/include/linux/perf_event.h > > @@ -1013,15 +1013,17 @@ static inline void perf_fetch_caller_reg > > static inline void > > perf_sw_event(u32 event_id, u64 nr, int nmi, struct pt_regs *regs, u64 addr) > > { > > - if (atomic_read(&perf_swevent_enabled[event_id])) { > > - struct pt_regs hot_regs; > > + struct pt_regs hot_regs; > > > > - if (!regs) { > > - perf_fetch_caller_regs(&hot_regs); > > - regs = &hot_regs; > > - } > > - __perf_sw_event(event_id, nr, nmi, regs, addr); > > + JUMP_LABEL(&perf_swevent_enabled[event_id], have_event); > > + return; > > + > > +have_event: > > + if (!regs) { > > + perf_fetch_caller_regs(&hot_regs); > > + regs = &hot_regs; > > } > > + __perf_sw_event(event_id, nr, nmi, regs, addr); > > } > > > > OK, so it appears I only compile tested this bit without jump_label > support, with that bit added back this horribly fails to compile like: > > In file included from /usr/src/linux-2.6/arch/x86/mm/fault.c:13: > /usr/src/linux-2.6/include/linux/perf_event.h: In function ‘perf_sw_event.clone.0’: > /usr/src/linux-2.6/include/linux/perf_event.h:1018: warning: asm operand 0 probably doesn’t match constraints > /usr/src/linux-2.6/include/linux/perf_event.h:1018: error: impossible constraint in ‘asm’ >
Ah, figured it out, it needs __attribute__((always_inline)), otherwise we end up with multiple keys for one label, which will clealy not work.
I thought we had a __force_inline macro but I can't seem to find that.
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