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. Before this commit, vm used normal style in 21 of 28 instances. The style regression is even smaller in kern -- 18 of 169 instances (3 in comments, and 1 of these in a loop doing a memset to a nonzero value, which was required before about FreeBSD-4 since memset() didn't exist in the kernel. memset() is still a slightly pessimized wrapper round bzero() when the value is nonzero, and a more pessimized loop otherwise). In FreeBSD-4, this style bug was not present in vm (0 of 16 instances) and was smaller in kern (6 of 121 instances (3 in comments, and 1 to #define a buggy memset() in terms of bzero() for the other 2)). Bruce _______________________________________________ svn-src-head@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
