On 12 October 2017 at 11:03, Andres Freund <andres@xxxxxxxxxxx> wrote: > On 2017-10-12 10:25:43 +0800, Craig Ringer wrote: >> On 4 October 2017 at 00:21, milist ujang <ujang.milist@xxxxxxxxx> wrote: >> > On Tue, Oct 3, 2017 at 8:49 PM, Craig Ringer <craig@xxxxxxxxxxxxxxx> wrote: >> >> >> >> >> >> Can you get stacks please? >> >> >> >> Use -g >> > >> > >> > # Events: 2K cpu-clock >> > # >> > # Overhead Command Shared Object Symbol >> > # ........ ........ ................. ............................ >> > # >> > 86.96% postgres [kernel.kallsyms] [k] __mutex_lock_common.isra.5 >> > | >> > --- __mutex_lock_common.isra.5 >> > read >> >> >> Unfortunately it looks like you're using a postgres built with >> -fomit-frame-pointers (the default) on x64, with an older perf not >> built with libunwind. This produces useless stacks. > > Just read this mail, but for libunwind to work you'd have to specify > "--call-graph dwarf", no? I think you're right. But only on a version of perf where it's available and used. I haven't recently checked if perf has finally grown the ability to load external debug symbols either. It never used to. -- Craig Ringer http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
