On Wed, 28 Jan 2009, Rainer Gerhards wrote: > Hi all, > > thanks to Lorenzo's help, we made good progress. It is too much to post > inside a mail, please have a look at my analysis of the bug: > > http://blog.gerhards.net/2009/01/rsyslog-data-race-analysis.html > > The short story is that we have at least improved the situation very > much and I hope to have fixes for all branches within the next couple of > days.
I just finished reading through this excellant write-up one small thing. you quote the spec Accesses to cacheable memory that are split across bus widths, cache lines, and page boundaries are not guaranteed to be atomic and then conclude that So aligned word-access does not guarantee (not even enhance the chance) of atomicity. I read that to mean that the alignment requirements are more complicated, not that alignment is useless. you should also look at the code that's generated by -Os, with the heavily cached systems that we have nowdays it's common that the code being smaller (and therefor more of the code fitting into the L1 cache) is more of an advantage than the optimizations that -O3 provides. congradulations on tracking down a nasty and subtle issue. David Lang > Rainer > >> -----Original Message----- >> From: [email protected] [mailto:rsyslog- >> [email protected]] On Behalf Of Rainer Gerhards >> Sent: Friday, January 16, 2009 3:22 PM >> To: rsyslog-users >> Subject: Re: [rsyslog] rsyslog still crashes >> >> Lorenzo, >> >> I have created a new branch "raceDebug" and done a first commit to it. >> The change is very lightweight. Please pull, compile as usual and give >> it a try. It spits out some info to stdout from time to time >> (hopefully). I am not sure if it aborts, depending on the output it > may >> or may not. Even if we get messages, they are probably not enough to >> pinpoint the bug, but I wanted to do something very light to see if > the >> bug stays. >> >> Feedback appreciated. >> >> Rainer > _______________________________________________ > rsyslog mailing list > http://lists.adiscon.net/mailman/listinfo/rsyslog > http://www.rsyslog.com > _______________________________________________ rsyslog mailing list http://lists.adiscon.net/mailman/listinfo/rsyslog http://www.rsyslog.com
