Date: Sun, 10 Jul 2016 04:33:16 +0000 (UTC) From: Konstantin Belousov <kib@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-10@freebsd.org Subject: svn commit: r302513 - stable/10/sys/vm Message-ID: <201607100433.u6A4XGiT068621@repo.freebsd.org>
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Author: kib Date: Sun Jul 10 04:33:16 2016 New Revision: 302513 URL: https://svnweb.freebsd.org/changeset/base/302513 Log: MFC r302236: Handle the vm_fault() handler race with the vm_object_collapse() sleepable scan. MFC r302317: Change type of the 'dead' variable to boolean. Modified: stable/10/sys/vm/vm_fault.c Directory Properties: stable/10/ (props changed) Modified: stable/10/sys/vm/vm_fault.c ============================================================================== --- stable/10/sys/vm/vm_fault.c Sun Jul 10 03:49:38 2016 (r302512) +++ stable/10/sys/vm/vm_fault.c Sun Jul 10 04:33:16 2016 (r302513) @@ -286,7 +286,7 @@ vm_fault_hold(vm_map_t map, vm_offset_t vm_prot_t prot; long ahead, behind; int alloc_req, era, faultcount, nera, reqpage, result; - boolean_t growstack, is_first_object_locked, wired; + boolean_t dead, growstack, is_first_object_locked, wired; int map_generation; vm_object_t next_object; vm_page_t marray[VM_FAULT_READ_MAX]; @@ -423,11 +423,18 @@ fast_failed: fs.pindex = fs.first_pindex; while (TRUE) { /* - * If the object is dead, we stop here + * If the object is marked for imminent termination, + * we retry here, since the collapse pass has raced + * with us. Otherwise, if we see terminally dead + * object, return fail. */ - if (fs.object->flags & OBJ_DEAD) { + if ((fs.object->flags & OBJ_DEAD) != 0) { + dead = fs.object->type == OBJT_DEAD; unlock_and_deallocate(&fs); - return (KERN_PROTECTION_FAILURE); + if (dead) + return (KERN_PROTECTION_FAILURE); + pause("vmf_de", 1); + goto RetryFault; } /*
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