On Tue, Aug 14, 2018 at 09:26:09PM -0400, Emilio G. Cota wrote: > On Tue, Aug 14, 2018 at 10:14:01 +0200, Paolo Bonzini wrote: > > On 13/08/2018 19:11, Emilio G. Cota wrote: > > Would it make sense to add a flag to sort by average wait time > > Done: > > (qemu) help info sync-profile > info sync-profile [-m] [max] -- show sync profiling info \ > for up to max entries (default: 10). By default, entries \ > are sorted by total wait time; -m sorts by mean wait time. > > (qemu) info sync-profile 3 > Type Object Call site Wait Time (s) Count > Average (us) > ------------------------------------------------------------------------------------ > condvar 0x560cc9909e50 cpus.c:1165 63.63428 16081 > 3957.11 > condvar 0x560cc9909e50 cpus.c:1415 0.21074 2 > 105371.07 > BQL mutex 0x560cc85a3fa0 util/rcu.c:269 0.20227 20 > 10113.60 > ------------------------------------------------------------------------------------ > > (qemu) info sync-profile -m 3 > Type Object Call site Wait Time (s) Count > Average (us) > ------------------------------------------------------------------------------------ > condvar 0x560cc9909e50 cpus.c:1415 0.21074 2 > 105371.07 > BQL mutex 0x560cc85a3fa0 util/rcu.c:269 0.20227 21 > 9632.00 > condvar 0x560cc9909e50 cpus.c:1165 71.92799 18167 > 3959.27 > ------------------------------------------------------------------------------------ > > >, and one to coalesce all mutexes for the same call site? > > I am not sure I understand. Do you mean to pass a specific call site, > so that we coalesce all entries related to the call site's object? > Or to keep the call sites separate, but only report entries related > to that specific call site's object?
I would guess Paolo means that whether we can merge entries that have the same call site but with different object addresses. I copied one example from the commit message of your patch 1: Type Object Call site Wait Time (s) Count Average (us) --------------------------------------------------------------------------------------- condvar 0x557ee3090e80 cpus.c:1084 1.69207 2916 580.27 condvar 0x557ee30ceb10 cpus.c:1084 1.43442 2404 596.68 ... IMHO merging of these two entries might be helpful when e.g. the condvar used there is dynamically created/destroyed, then in this case the object pointer might not that helpful, instead the statistics of all the entries for the same call site might tell more. Regards, -- Peter Xu
