On Thu, Nov 22, 2018 at 09:50:15AM +0800, Wangnan (F) wrote: > > > On 2018/11/21 21:11, Arnaldo Carvalho de Melo wrote: > > Em Wed, Nov 21, 2018 at 07:45:28AM +0000, Song Liu escreveu: > >> Hi, > >> > >> I found perf-record --tail-synthesize without --overwrite breaks symbols > >> for perf-script, perf-report, etc. For example: > >> > >> [root@]# ~/perf record -ag --tail-synthesize -- sleep 1 > >> [ perf record: Woken up 1 times to write data ] > >> [ perf record: Captured and wrote 1.129 MB perf.data (3531 samples) ] > >> [root@]# ~/perf script | head > >> swapper 0 [000] 1250675.051971: 1 cycles:ppp: > >> ffffffff81009e15 [unknown] ([unknown]) > >> ffffffff81196b19 [unknown] ([unknown]) > >> ffffffff81196579 [unknown] ([unknown]) > >> ffffffff81110ca7 [unknown] ([unknown]) > >> ffffffff81a01f4a [unknown] ([unknown]) > >> ffffffff81a017bf [unknown] ([unknown]) > >> ffffffff8180e17a [unknown] ([unknown]) > >> > >> perf-record with --overwrite does NOT have this issue. > >> > >> After digging into this, I found this issue is introduced by commit > >> a73e24d240bc136619d382b1268f34d75c9d25ce. > >> > >> Reverting this commit does fix this issue. However, on a second thought, > >> I feel it is probably better just drop --tail-synthesize, as it doesn't > >> make much sense without --overwrite. All we need is to do tail_synthesize > >> when --overwrite is set. > >> > > Some cases we use --overwrite without --tail-synthesize. How about setting > --tail-synthesize when selecting --overwrite by default, throw a warning > when --overwrite is not set and leave a --no-tail-synthesize option?
sounds good to me thanks, jirka
