Author: kib Date: Fri Dec 29 20:33:56 2017 New Revision: 327359 URL: https://svnweb.freebsd.org/changeset/base/327359
Log: Do not lock vm map in swapout_procs(). Neither swapout_procs() nor swapout() access the map. Since the process' vmspace is referenced only to obtain the pointer to the vm_map, the reference is not needed as well. Reviewed by: alc Sponsored by: The FreeBSD Foundation MFC after: 1 week Differential revision: https://reviews.freebsd.org/D13681 Modified: head/sys/vm/vm_swapout.c Modified: head/sys/vm/vm_swapout.c ============================================================================== --- head/sys/vm/vm_swapout.c Fri Dec 29 20:30:10 2017 (r327358) +++ head/sys/vm/vm_swapout.c Fri Dec 29 20:33:56 2017 (r327359) @@ -729,7 +729,6 @@ swapout_procs(int action) { struct proc *p; struct thread *td; - struct vmspace *vm; int minslptime, slptime; bool didswap; @@ -763,24 +762,6 @@ retry: PROC_UNLOCK(p); sx_sunlock(&allproc_lock); - /* - * Do not swapout a process that - * is waiting for VM data - * structures as there is a possible - * deadlock. Test this first as - * this may block. - * - * Lock the map until swapout - * finishes, or a thread of this - * process may attempt to alter - * the map. - */ - vm = vmspace_acquire_ref(p); - if (vm == NULL) - goto nextproc2; - if (!vm_map_trylock(&vm->vm_map)) - goto nextproc1; - PROC_LOCK(p); if (p->p_lock != 1 || (p->p_flag & (P_STOPPED_SINGLE | P_TRACED | P_SYSTEM)) != 0) @@ -867,17 +848,11 @@ retry: if (swapout(p) == 0) didswap = true; PROC_UNLOCK(p); - vm_map_unlock(&vm->vm_map); - vmspace_free(vm); goto retry; } } nextproc: PROC_UNLOCK(p); - vm_map_unlock(&vm->vm_map); -nextproc1: - vmspace_free(vm); -nextproc2: sx_slock(&allproc_lock); PRELE(p); } _______________________________________________ svn-src-all@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
