On 04/04/2017 02:49 PM, Rob Clark wrote: > On Tue, Apr 4, 2017 at 8:45 AM, Thomas Hellstrom <thellst...@vmware.com> > wrote: >> On 04/04/2017 02:34 PM, Rob Clark wrote: >>> On Tue, Apr 4, 2017 at 1:49 AM, Thomas Hellstrom <thellst...@vmware.com> >>> wrote: >>>> But one more worrying thing is that with these fixes, debug_flush gets >>>> too slow to be usable. I get about one frame every 5 seconds from Ubuntu >>>> compiz. The culprit seems to be unw_get_proc_name(). Is there a way we >>>> can save intermediate information during backtrace capture and call this >>>> function at printout time? >>> btw, is it common to capture many more backtraces than you print? >>> (Just to check if defering the unw_get_proc_name() would actually help >>> anything..) >> Yes. The debug_flush functionality captures the backtrace on each map in >> case someone would flush when mapped or try a recursive map. Only then >> they are printed. >> >> FWIW in u_debug_symbol.c, José has implemented a hash table for name >> lookups. Perhaps one solution would to save the IP and insert the >> function name in the hash table with the IP as key. > Yeah, this might work.. I'm just digging through the libunwind code to > see if there is a better way (since in theory it should be possible to > defer the symbol lookup quite easily.. although even then a hashtable > sound like it could improve things) > > fwiw, if we end up going the backtrace() route, I noticed > https://urldefense.proofpoint.com/v2/url?u=https-3A__manned.org_unw-5Fbacktrace_e7940441&d=DwIFaQ&c=uilaK90D4TOVoH58JNXRgQ&r=wnSlgOCqfpNS4d02vP68_E9q2BNMCwfD2OZ_6dCFVQQ&m=jG5LQNduxtu9nyZQ5feQ788BZ1q5fkP6HmY3tmTbe_U&s=EdRhwfvtkUAKaANSnmPXmAywHHtBb1_B-DaM_H-J6PI&e= > .. perhaps that could > provide a fallback backtrace() implementation on libc's which don't > have backtrace()?
Sure. However in that case it seems problematic to get a decent file-offset printout. We'd only get the hex pointer. /Thomas > BR, > -R _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
