Module Name: src
Committed By: rmind
Date: Wed Aug 31 22:16:54 UTC 2011
Modified Files:
src/sys/miscfs/genfs: genfs_io.c
Log Message:
genfs_do_directio: acquire the lock of page owner for now and fix PR/45177.
Will be revisited to avoid locking dance and be more efficient, e.g. we can
use unmanaged-mapping by allocating with colouring in mind.
To generate a diff of this commit:
cvs rdiff -u -r1.49 -r1.50 src/sys/miscfs/genfs/genfs_io.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/miscfs/genfs/genfs_io.c
diff -u src/sys/miscfs/genfs/genfs_io.c:1.49 src/sys/miscfs/genfs/genfs_io.c:1.50
--- src/sys/miscfs/genfs/genfs_io.c:1.49 Sun Jun 12 03:35:58 2011
+++ src/sys/miscfs/genfs/genfs_io.c Wed Aug 31 22:16:54 2011
@@ -1,4 +1,4 @@
-/* $NetBSD: genfs_io.c,v 1.49 2011/06/12 03:35:58 rmind Exp $ */
+/* $NetBSD: genfs_io.c,v 1.50 2011/08/31 22:16:54 rmind Exp $ */
/*
* Copyright (c) 1982, 1986, 1989, 1993
@@ -31,7 +31,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: genfs_io.c,v 1.49 2011/06/12 03:35:58 rmind Exp $");
+__KERNEL_RCSID(0, "$NetBSD: genfs_io.c,v 1.50 2011/08/31 22:16:54 rmind Exp $");
#include <sys/param.h>
#include <sys/systm.h>
@@ -1748,6 +1748,8 @@
int error, rv, poff, koff;
const int pgoflags = PGO_CLEANIT | PGO_SYNCIO | PGO_JOURNALLOCKED |
(rw == UIO_WRITE ? PGO_FREE : 0);
+ struct vm_page *pg;
+ kmutex_t *slock;
/*
* For writes, verify that this range of the file already has fully
@@ -1804,13 +1806,22 @@
kva = uvm_km_alloc(kernel_map, klen, 0,
UVM_KMF_VAONLY | UVM_KMF_WAITVA);
puva = trunc_page(uva);
- mutex_enter(vp->v_interlock);
for (poff = 0; poff < klen; poff += PAGE_SIZE) {
rv = pmap_extract(upm, puva + poff, &pa);
KASSERT(rv);
+ pg = PHYS_TO_VM_PAGE(pa);
+
+retry1: /* XXX: Rework to not use managed-mappings.. */
+ mutex_enter(&uvm_pageqlock);
+ slock = uvmpd_trylockowner(pg);
+ mutex_exit(&uvm_pageqlock);
+ if (slock == NULL) {
+ kpause("gendiolk", false, 1, slock);
+ goto retry1;
+ }
pmap_enter(kpm, kva + poff, pa, prot, prot | PMAP_WIRED);
+ mutex_exit(slock);
}
- mutex_exit(vp->v_interlock);
pmap_update(kpm);
/*
@@ -1825,9 +1836,24 @@
* Tear down the kernel mapping.
*/
- mutex_enter(vp->v_interlock);
- pmap_remove(kpm, kva, kva + klen);
- mutex_exit(vp->v_interlock);
+ for (koff = 0; koff < klen; koff += PAGE_SIZE) {
+ vaddr_t sva = kva + koff;
+
+ rv = pmap_extract(kpm, sva, &pa);
+ KASSERT(rv);
+ pg = PHYS_TO_VM_PAGE(pa);
+
+retry2: /* XXX: Rework to not use managed-mappings.. */
+ mutex_enter(&uvm_pageqlock);
+ slock = uvmpd_trylockowner(pg);
+ mutex_exit(&uvm_pageqlock);
+ if (slock == NULL) {
+ kpause("gendiolk", false, 1, slock);
+ goto retry2;
+ }
+ pmap_remove(kpm, sva, sva + PAGE_SIZE);
+ mutex_exit(slock);
+ }
pmap_update(kpm);
uvm_km_free(kernel_map, kva, klen, UVM_KMF_VAONLY);
@@ -1838,4 +1864,3 @@
uvm_vsunlock(vs, (void *)uva, len);
return error;
}
-
