Date: Mon, 17 Mar 2003 20:31:26 -0500 (EST) From: Jeff Roberson <jroberson@chesapeake.net> To: Kirk McKusick <mckusick@beastie.mckusick.com> Cc: Poul-Henning Kamp <phk@phk.freebsd.dk>, <dwmalone@FreeBSD.org>, El Vampiro <vampiro@rootshell.ru>, "Evgueni V. Gavrilov" <aquatique@rusunix.org>, Mike Makonnen <mtm@identd.net>, <src-committers@FreeBSD.org>, <cvs-src@FreeBSD.org>, <cvs-all@FreeBSD.org> Subject: Re: kern/42277 Message-ID: <20030317202944.A66343-100000@mail.chesapeake.net> In-Reply-To: <200303172341.h2HNfRFL014201@beastie.mckusick.com>
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On Mon, 17 Mar 2003, Kirk McKusick wrote: > Date: Mon, 17 Mar 2003 16:22:05 -0500 (EST) > From: Jeff Roberson <jroberson@chesapeake.net> > To: Poul-Henning Kamp <phk@phk.freebsd.dk> > cc: Kirk McKusick <mckusick@mckusick.com>, <dwmalone@FreeBSD.org>, > El Vampiro <vampiro@rootshell.ru>, > "Evgueni V. Gavrilov" <aquatique@rusunix.org>, > Mike Makonnen <mtm@identd.net>, <src-committers@FreeBSD.org>, > <cvs-src@FreeBSD.org>, <cvs-all@FreeBSD.org> > Subject: Re: kern/42277 > X-ASK-Info: Whitelist match > > UMA has a facility to track the previous owner of the memory. > Assuming that is the problem I could give you a way to cache this > information so we can print it out when we detect corruption. I > can work on this tonight. What is the repro? > > Cheers, > Jeff > > I have not had any success in reproducing the problem on my machines, > but I am mostly running on 5.X these days. Evgueni V. Gavrilov (copied > on this message) seems to be able to produce the problem about once a > day on his machines. He is also very willing to help out by testing > patches and sending back reports. So, if you are able to provide him > with a patch to collect the information, I am sure that he will run it > and send back the results. He and I have already gone through all the > 128-byte structures reported by `vmstat -m' looking for ones with a > short at 64-bytes and found no viable candidates. So, I was feeling > rather stuck. But it sounds like you have a viable way of tracking > this down. > > Kirk McKusick > I don't have any 4.x machines. You can do the following though.. Add a "struct malloc_type *" as the first field of your structure. In free() cache a pointer to the malloc_type * in the first location in the free memory. When you detect corruption print out the malloc_type member of your structure. This should be the last owner. You'll have to disable the INVARIANTS memory trashing though. Cheers, Jeff To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe cvs-src" in the body of the message
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