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://manned.org/unw_backtrace/e7940441 .. perhaps that could provide a fallback backtrace() implementation on libc's which don't have backtrace()? BR, -R _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
