Hi Jiří, were you able to reproduce the issue? I may also upload perf-archive if that would help. Petr
On Tue, Nov 24, 2020 at 07:15:19PM +0100, Petr Malat wrote: > Hi! > On Tue, Nov 24, 2020 at 03:36:45PM +0100, Jiri Olsa wrote: > > On Tue, Nov 24, 2020 at 11:29:15AM +0100, Petr Malat wrote: > > > Both mmapped and compressed events can be split by the buffer boundary, > > > it doesn't make sense to handle them differently. > > I'm going to need more than this, if there's a problem > > with current code please share more details, what's > > broken and how it shows > It's easy to trigger the problem - make a perf recording larger than > MMAP_SIZE (32MB on 32-bit platform) and run perf report on it. There > is a small chance recorded events will be aligned on the 32 MB > boundary and in that case just repeat the test. > > The problem was introduced by "perf session: Avoid infinite loop when > seeing invalid header.size", which instead of aborting the execution > when there is a truncated event at the end of the file just terminated > execution whenever there is a split event. Later then the problem has > been noticed for compressed events and fixed by "perf session: Fix > decompression of PERF_RECORD_COMPRESSED records" by effectively > reverting "perf session: Avoid infinite loop when seeing invalid > header.size" for compressed events, which left uncompressed events > broken. > > I think the best is to revert these 2 changes and fix the original > problem by aborting when there is no actual shift during remapping - as > long as we shift, it's clear we must approach the end of the file so > such an algorithm can't loop forever. > BR, > Petr