Re: [PATCH/RFC] Make perf_event_open() propagate errors for use in bpf_perf_event_open()

2019-01-18 Thread Peter Zijlstra
On Fri, Jan 18, 2019 at 12:09:38PM -0300, Arnaldo Carvalho de Melo wrote: > commit 1b3b3dee572d0b77a316ab6715091201be6832de > Author: Arnaldo Carvalho de Melo > Date: Fri Jan 11 13:20:20 2019 -0300 > > perf: Make perf_event_output() propagate the output() return > > For the

Re: [PATCH/RFC] Make perf_event_open() propagate errors for use in bpf_perf_event_open()

2019-01-18 Thread Arnaldo Carvalho de Melo
Em Fri, Jan 18, 2019 at 03:52:37PM +0100, Peter Zijlstra escreveu: > On Fri, Jan 11, 2019 at 12:55:38PM -0300, Arnaldo Carvalho de Melo wrote: > > Hi Peter, > > > > bpf_perf_event_open() already returns a value, but if > > perf_event_output's output_begin (mostly perf_output_begin) fails, > >

Re: [PATCH/RFC] Make perf_event_open() propagate errors for use in bpf_perf_event_open()

2019-01-18 Thread Peter Zijlstra
On Fri, Jan 11, 2019 at 12:55:38PM -0300, Arnaldo Carvalho de Melo wrote: > Hi Peter, > > bpf_perf_event_open() already returns a value, but if > perf_event_output's output_begin (mostly perf_output_begin) fails, > the only way to know about that is looking before/after the rb->lost, >

Re: [PATCH/RFC] Make perf_event_open() propagate errors for use in bpf_perf_event_open()

2019-01-12 Thread Jamal Hadi Salim
On 2019-01-11 10:55 a.m., Arnaldo Carvalho de Melo wrote: Hi Peter, bpf_perf_event_open() already returns a value, but if perf_event_output's output_begin (mostly perf_output_begin) fails, the only way to know about that is looking before/after the rb->lost, right? For ring

[PATCH/RFC] Make perf_event_open() propagate errors for use in bpf_perf_event_open()

2019-01-11 Thread Arnaldo Carvalho de Melo
Hi Peter, bpf_perf_event_open() already returns a value, but if perf_event_output's output_begin (mostly perf_output_begin) fails, the only way to know about that is looking before/after the rb->lost, right? For ring buffer users that is ok, we'll get a PERF_RECORD_LOST, etc, but