Messages in this thread | | | Subject | Re: [PATCH 09/17] perf tools: Detect avalibility of write_backward | From | "Wangnan (F)" <> | Date | Fri, 20 May 2016 23:31:44 +0800 |
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On 2016/5/13 21:08, Arnaldo Carvalho de Melo wrote: > Em Fri, May 13, 2016 at 07:56:06AM +0000, Wang Nan escreveu: >> Detect avalibility of write_backward and save the result into >> record_opts. With write_backward the start pointer of a ring >> buffer mapped read only can be found reliably. > We have perf_missing_features for that, please try to use it.
I'll try it, but write_backward can't fallback, if kernel doesn't support it, I think we'd better throw an error earlier. Using perf_missing_features we get error during opening the event, so if we want to fail earlier we still need API probing.
Thank you.
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