Date: Thu, 25 Jul 2013 10:11:28 +0200 From: Hans Petter Selasky <hps@bitfrost.no> To: Bruce Evans <brde@optusnet.com.au> Cc: svn-src-head@FreeBSD.org, svn-src-all@FreeBSD.org, Tim Kientzle <kientzle@FreeBSD.org>, src-committers@FreeBSD.org Subject: Re: svn commit: r253636 - head/sys/vm Message-ID: <51F0DDB0.7080102@bitfrost.no> In-Reply-To: <20130725171038.O841@besplex.bde.org> References: <201307250348.r6P3mbsG049595@svn.freebsd.org> <20130725171038.O841@besplex.bde.org>
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On 07/25/13 09:26, Bruce Evans wrote: > On Thu, 25 Jul 2013, Tim Kientzle wrote: > >> Log: >> Clear entire map structure including locks so that the >> locks don't accidentally appear to have been already >> initialized. >> >> In particular, this fixes a consistent kernel crash on >> armv6 with: >> panic: lock "vm map (user)" 0xc09cc050 already initialized >> that appeared with r251709. >> >> PR: arm/180820 >> >> Modified: >> head/sys/vm/vm_map.c >> >> Modified: head/sys/vm/vm_map.c >> ============================================================================== >> >> --- head/sys/vm/vm_map.c Thu Jul 25 03:44:12 2013 (r253635) >> +++ head/sys/vm/vm_map.c Thu Jul 25 03:48:37 2013 (r253636) >> @@ -239,8 +239,7 @@ vm_map_zinit(void *mem, int size, int fl >> vm_map_t map; >> >> map = (vm_map_t)mem; >> - map->nentries = 0; >> - map->size = 0; >> + memset(map, 0, sizeof(*map)); >> mtx_init(&map->system_mtx, "vm map (system)", NULL, MTX_DEF | >> MTX_DUPOK); >> sx_init(&map->lock, "vm map (user)"); >> return (0); > > memset() to value 0 is spelled bzero() in the kernel. > Hi, Is this the "memset vs bzero" or "batman vs superman" discussion again ;-) The structure looks like some size, so bzero() might run faster than memset() depending on the compiler settings. Should be profiled before changed! --HPS
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