Date: Fri, 15 May 2009 14:26:00 -0400 From: John Baldwin <jhb@freebsd.org> To: Ben Kelly <ben@wanderview.com> Cc: freebsd-current@freebsd.org, Robert Watson <rwatson@freebsd.org> Subject: Re: [patch] corrupt memstat_kvm_malloc(3) output and dtrace Message-ID: <200905151426.00489.jhb@freebsd.org> In-Reply-To: <6A55FF0C-EEE2-473A-867C-489E3F18463D@wanderview.com> References: <9A637B27-7C89-49BA-8385-A5B2D5D54BB3@wanderview.com> <200905121028.58998.jhb@freebsd.org> <6A55FF0C-EEE2-473A-867C-489E3F18463D@wanderview.com>
next in thread | previous in thread | raw e-mail | index | archive | help
On Friday 15 May 2009 1:17:09 pm Ben Kelly wrote: > On May 12, 2009, at 10:28 AM, John Baldwin wrote: > > On Wednesday 06 May 2009 1:00:09 am Ben Kelly wrote: > >> On May 5, 2009, at 10:18 AM, Ben Kelly wrote: > >>> While debugging a problem recently with Alexander Leidinger we > >>> noticed that crashinfo(8) was producing corrupt vmstat -m output. > >>> After doing some digging it appears that memstat_kvm_malloc(3) might > >>> have been broken by this commit: > >>> > >>> http://svn.freebsd.org/viewvc/base?view=revision&revision=179222 > >>> > >>> The problem is that memstat_kvm_malloc(3) assumes that > >>> malloc_type_internal starts with an array of malloc_types_stats > >>> structures. This assumption is no longer true, though, as > >>> mti_probes was inserted at the start of the structure. > >>> > >>> It appears that this (untested) patch might fix the problem: > >>> > >>> http://www.wanderview.com/svn/public/misc/zfs/vmstat_kvm_malloc.diff > >>> > >>> I'm not very familiar with dtrace, though. Does anyone know if this > >>> would cause problems? > >> > >> Just FYI, I was able to recompile and test this patch tonight. It > >> seems to have fixed vmstat -M $core -m output on my machine. > > > > I think that it would be better to update memstat_kvm_malloc(3) > > though. I'm > > also curious why libmemstat isn't just using malloc_types_internal > > directly. > > I've updated the patch so that memstat_kvm_malloc(3) uses the > malloc_type_internal definition to find the start of the statistics > array. This also appears to fix the problem on my server. Thanks! I've committed the fix. -- John Baldwin
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200905151426.00489.jhb>