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Groups > linux.kernel > #1209418
| From | Alexey Brodkin <Alexey.Brodkin@synopsys.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH v2 3/8] ARCv2: perf: implement "event_set_period" for future use with interrupts |
| Date | 2015-08-18 20:10 +0200 |
| Message-ID | <pYTuF-5ua-9@gated-at.bofh.it> (permalink) |
| References | <pU8E1-57u-3@gated-at.bofh.it> <pU8E2-57u-19@gated-at.bofh.it> <pYTl0-53y-15@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
Hi Peter, On Tue, 2015-08-18 at 19:52 +-0200, Peter Zijlstra wrote: +AD4- On Wed, Aug 05, 2015 at 06:13:29PM +-0300, Alexey Brodkin wrote: +AD4- +AD4- Even though this hardware implementation allows for more flexibility, +AD4- +AD4- in Linux kernel we decided to mimic behavior of other architectures this +AD4- +AD4- way: +AD4- +AD4- +AD4- +AD4- +AFs-1+AF0- Set limit value as half of counter's max value (to allow counter to +AD4- +AD4- run after reaching it limit, see below for more explanation): +AD4- +AD4- ----------+AD4-8----------- +AD4- +AD4- arc+AF8-pmu-+AD4-max+AF8-period +AD0- (1ULL +ADwAPA- counter+AF8-size) / 2 - 1ULL+ADs- +AD4- +AD4- ----------+AD4-8----------- +AD4- +AD4- +AD4- +AEAAQA- -317,10 +-365,11 +AEAAQA- static int arc+AF8-pmu+AF8-device+AF8-probe(struct platform+AF8-device +ACo-pdev) +AD4- +AD4- return -ENOMEM+ADs- +AD4- +AD4- +AD4- +AD4- arc+AF8-pmu-+AD4-n+AF8-counters +AD0- pct+AF8-bcr.c+ADs- +AD4- +AD4- - arc+AF8-pmu-+AD4-counter+AF8-size +AD0- 32 +- (pct+AF8-bcr.s +ADwAPA- 4)+ADs- +AD4- +AD4- +- counter+AF8-size +AD0- 32 +- (pct+AF8-bcr.s +ADwAPA- 4)+ADs- +AD4- +AD4- +- arc+AF8-pmu-+AD4-max+AF8-period +AD0- (1ULL +ADwAPA- counter+AF8-size) - 1ULL+ADs- +AD4- +AD4- +AD4- +AD4- I don't see that /2 there.. My comment was a bit too early. That +ACI-/2+ACI- was actually introduced in the subsequent commit. Do you think I need to do a re-spin of that patch with commit message which matches real code (i.e. no +ACI-/2+ACI-)? -Alexey-- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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[PATCH v2 3/8] ARCv2: perf: implement "event_set_period" for future use with interrupts Alexey Brodkin <Alexey.Brodkin@synopsys.com> - 2015-08-05 17:20 +0200
Re: [PATCH v2 3/8] ARCv2: perf: implement "event_set_period" for future use with interrupts Peter Zijlstra <peterz@infradead.org> - 2015-08-18 20:00 +0200
Re: [PATCH v2 3/8] ARCv2: perf: implement "event_set_period" for future use with interrupts Peter Zijlstra <peterz@infradead.org> - 2015-08-18 20:00 +0200
Re: [PATCH v2 3/8] ARCv2: perf: implement "event_set_period" for future use with interrupts Alexey Brodkin <Alexey.Brodkin@synopsys.com> - 2015-08-18 20:10 +0200
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