Date: Thu, 11 Jul 2013 03:57:54 +0000 (UTC) From: Neel Natu <neel@FreeBSD.org> To: src-committers@freebsd.org, svn-src-projects@freebsd.org Subject: svn commit: r253182 - projects/bhyve_npt_pmap/sys/amd64/vmm Message-ID: <201307110357.r6B3vsvN010041@svn.freebsd.org>
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Author: neel Date: Thu Jul 11 03:57:53 2013 New Revision: 253182 URL: http://svnweb.freebsd.org/changeset/base/253182 Log: Don't prevent the process address space from being swapped out while it is trying to resolve a page fault. This could potentially aggravate an already low memory condition and lead to a deadlock. A more detailed explanation is here: http://lists.freebsd.org/pipermail/svn-src-projects/2013-July/007215.html Pointed out by: kib Modified: projects/bhyve_npt_pmap/sys/amd64/vmm/vmm.c Modified: projects/bhyve_npt_pmap/sys/amd64/vmm/vmm.c ============================================================================== --- projects/bhyve_npt_pmap/sys/amd64/vmm/vmm.c Thu Jul 11 03:54:35 2013 (r253181) +++ projects/bhyve_npt_pmap/sys/amd64/vmm/vmm.c Thu Jul 11 03:57:53 2013 (r253182) @@ -445,25 +445,14 @@ vm_gpa_hold(struct vm *vm, vm_paddr_t gp { int rv, pageoff; vm_page_t m; - struct proc *p; pageoff = gpa & PAGE_MASK; if (len > PAGE_SIZE - pageoff) panic("vm_gpa_hold: invalid gpa/len: 0x%016lx/%lu", gpa, len); - p = curthread->td_proc; - - PROC_LOCK(p); - p->p_lock++; - PROC_UNLOCK(p); - rv = vm_fault_hold(&vm->vmspace->vm_map, trunc_page(gpa), reqprot, VM_FAULT_NORMAL, &m); - PROC_LOCK(p); - p->p_lock--; - PROC_UNLOCK(p); - if (rv == KERN_SUCCESS) { *cookie = m; return ((void *)(PHYS_TO_DMAP(VM_PAGE_TO_PHYS(m)) + pageoff)); @@ -748,8 +737,6 @@ static int vm_handle_paging(struct vm *vm, int vcpuid, boolean_t *retu) { int rv; - struct thread *td; - struct proc *p; struct vm_map *map; vm_prot_t ftype; struct vcpu *vcpu; @@ -758,21 +745,11 @@ vm_handle_paging(struct vm *vm, int vcpu vcpu = &vm->vcpu[vcpuid]; vme = &vcpu->exitinfo; - td = curthread; - p = td->td_proc; map = &vm->vmspace->vm_map; ftype = vme->u.paging.fault_type; - PROC_LOCK(p); - p->p_lock++; - PROC_UNLOCK(p); - rv = vm_fault(map, vme->u.paging.gpa, ftype, VM_FAULT_NORMAL); - PROC_LOCK(p); - p->p_lock--; - PROC_UNLOCK(p); - if (rv != KERN_SUCCESS) return (EFAULT);
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