On 08/11/13 16:41, David Ahern wrote: > On 11/8/13, 2:11 AM, Adrian Hunter wrote: >> This prevents: >> >> --out-pages=0 >> >> from working e.g. >> >> tools/perf/perf record -vv --out-pages=0 uname >> rounding mmap pages size to 4096 (1 pages) >> >> Although without this patch: >> >> tools/perf/perf record -vv --out-pages=0 uname >> --mmap_pages/-m value must be a power of two. >> usage: perf record [<options>] [<command>] >> or: perf record [<options>] -- <command> [<options>] >> >> --out-pages <pages> >> Number of pages or size with units to use for >> output (default 64M) >> >> Also there is: >> >> tools/perf/perf record -vv --no-out-pages uname >> Segmentation fault (core dumped) > > This is problem with perf_evlist__parse_mmap_pages(); same thing happens > with --no-map-pages. > > With the attached both round a 0 up to 1 page: > > [daahern@nxos-vdc-dev3 perf]$ perf record --out-pages 0 uname > rounding mmap pages size to 4096 (1 pages)
Your code looks like out_pages = 0 selects write() instead of mmap(). So it you can't set out_pages = 0, how do you select write()? > Linux > [ perf record: Woken up 1 times to write data ] > [ perf record: Captured and wrote 0.008 MB perf.data (~339 samples) ] > > [daahern@nxos-vdc-dev3 perf]$ perf record --mmap-pages 0 uname > rounding mmap pages size to 4096 (1 pages) > Linux > [ perf record: Woken up 1 times to write data ] > [ perf record: Captured and wrote 0.008 MB perf.data (~339 samples) ] > > [daahern@nxos-vdc-dev3 perf]$ perf record --no-mmap-pages uname > > usage: perf record [<options>] [<command>] > or: perf record [<options>] -- <command> [<options>] > > -m, --mmap-pages <pages> > number of mmap data pages > David > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
