[src/yamt-pagecache]: src/sys/arch/x86 share a lock among pmap uobjs

[yamt <yamt%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/1654c83c6c78
branches:  yamt-pagecache
changeset: 770833:1654c83c6c78
user:      yamt <yamt%NetBSD.org@localhost>
date:      Fri Nov 18 00:51:28 2011 +0000

description:
share a lock among pmap uobjs

diffstat:

 sys/arch/x86/include/pmap.h |   9 +++------
 sys/arch/x86/x86/pmap.c     |  39 +++++++--------------------------------
 2 files changed, 10 insertions(+), 38 deletions(-)

diffs (142 lines):

diff -r aed02cdc29eb -r 1654c83c6c78 sys/arch/x86/include/pmap.h
--- a/sys/arch/x86/include/pmap.h       Mon Nov 14 14:24:54 2011 +0000
+++ b/sys/arch/x86/include/pmap.h       Fri Nov 18 00:51:28 2011 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: pmap.h,v 1.43.2.1 2011/11/10 14:31:43 yamt Exp $       */
+/*     $NetBSD: pmap.h,v 1.43.2.2 2011/11/18 00:51:28 yamt Exp $       */
 
 /*
  * Copyright (c) 1997 Charles D. Cranor and Washington University.
@@ -130,9 +130,7 @@
  * note that the pm_obj contains the lock pointer, the reference count,
  * page list, and number of PTPs within the pmap.
  *
- * pm_lock is the same as the lock for vm object 0.  Changes to
- * the other objects may only be made if that lock has been taken
- * (the other object locks are only used when uvm_pagealloc is called)
+ * pm_lock is shared among vm objects.
  *
  * XXX If we ever support processor numbers higher than 31, we'll have
  * XXX to rethink the CPU mask.
@@ -140,8 +138,7 @@
 
 struct pmap {
        struct uvm_object pm_obj[PTP_LEVELS-1]; /* objects for lvl >= 1) */
-#define        pm_lock pm_obj[0].vmobjlock
-       kmutex_t pm_obj_lock[PTP_LEVELS-1];     /* locks for pm_objs */
+       kmutex_t pm_lock[1];            /* lock for pm_objs */
        LIST_ENTRY(pmap) pm_list;       /* list (lck by pm_list lock) */
        pd_entry_t *pm_pdir;            /* VA of PD (lck by object lock) */
        paddr_t pm_pdirpa[PDP_SIZE];    /* PA of PDs (read-only after create) */
diff -r aed02cdc29eb -r 1654c83c6c78 sys/arch/x86/x86/pmap.c
--- a/sys/arch/x86/x86/pmap.c   Mon Nov 14 14:24:54 2011 +0000
+++ b/sys/arch/x86/x86/pmap.c   Fri Nov 18 00:51:28 2011 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: pmap.c,v 1.137.2.3 2011/11/10 14:32:36 yamt Exp $      */
+/*     $NetBSD: pmap.c,v 1.137.2.4 2011/11/18 00:51:28 yamt Exp $      */
 
 /*-
  * Copyright (c) 2008, 2010 The NetBSD Foundation, Inc.
@@ -171,7 +171,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.137.2.3 2011/11/10 14:32:36 yamt Exp $");
+__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.137.2.4 2011/11/18 00:51:28 yamt Exp $");
 
 #include "opt_user_ldt.h"
 #include "opt_lockdebug.h"
@@ -324,24 +324,6 @@
 static vaddr_t pmap_maxkvaddr;
 
 /*
- * XXX kludge: dummy locking to make KASSERTs in uvm_page.c comfortable.
- * actual locking is done by pm_lock.
- */
-#if defined(DIAGNOSTIC)
-#define        PMAP_SUBOBJ_LOCK(pm, idx) \
-       KASSERT(mutex_owned((pm)->pm_lock)); \
-       if ((idx) != 0) \
-               mutex_enter((pm)->pm_obj[(idx)].vmobjlock)
-#define        PMAP_SUBOBJ_UNLOCK(pm, idx) \
-       KASSERT(mutex_owned((pm)->pm_lock)); \
-       if ((idx) != 0) \
-               mutex_exit((pm)->pm_obj[(idx)].vmobjlock)
-#else /* defined(DIAGNOSTIC) */
-#define        PMAP_SUBOBJ_LOCK(pm, idx)       /* nothing */
-#define        PMAP_SUBOBJ_UNLOCK(pm, idx)     /* nothing */
-#endif /* defined(DIAGNOSTIC) */
-
-/*
  * Misc. event counters.
  */
 struct evcnt pmap_iobmp_evcnt;
@@ -1224,10 +1206,10 @@
         */
 
        kpm = pmap_kernel();
+       mutex_init(kpm->pm_lock, MUTEX_DEFAULT, IPL_NONE);
        for (i = 0; i < PTP_LEVELS - 1; i++) {
-               mutex_init(&kpm->pm_obj_lock[i], MUTEX_DEFAULT, IPL_NONE);
                uvm_obj_init(&kpm->pm_obj[i], NULL, false, 1);
-               uvm_obj_setlock(&kpm->pm_obj[i], &kpm->pm_obj_lock[i]);
+               uvm_obj_setlock(&kpm->pm_obj[i], kpm->pm_lock);
                kpm->pm_ptphint[i] = NULL;
        }
        memset(&kpm->pm_list, 0, sizeof(kpm->pm_list));  /* pm_list not used */
@@ -1781,10 +1763,7 @@
            pa == VM_PAGE_TO_PHYS(pmap->pm_ptphint[lidx])) {
                return (pmap->pm_ptphint[lidx]);
        }
-       PMAP_SUBOBJ_LOCK(pmap, lidx);
        pg = uvm_pagelookup(&pmap->pm_obj[lidx], ptp_va2o(va, level));
-       PMAP_SUBOBJ_UNLOCK(pmap, lidx);
-
        KASSERT(pg == NULL || pg->wire_count >= 1);
        return pg;
 }
@@ -1944,7 +1923,6 @@
 
                obj = &pmap->pm_obj[i-2];
                l = curlwp;
-               PMAP_SUBOBJ_LOCK(pmap, i - 2);
                ncsw = l->l_ncsw;
                ptp = uvm_pagealloc(obj, ptp_va2o(va, i - 1), NULL,
                    UVM_PGA_USERESERVE|UVM_PGA_ZERO);
@@ -1957,13 +1935,10 @@
                        if (ptp != NULL) {
                                uvm_pagefree(ptp);
                        }
-                       PMAP_SUBOBJ_UNLOCK(pmap, i - 2);
                        /* XXX shut up the assertion in pmap_unmap_ptes */
                        pmap->pm_ncsw = l->l_ncsw;
                        return EAGAIN;
                }
-               PMAP_SUBOBJ_UNLOCK(pmap, i - 2);
-
                if (ptp == NULL)
                        return ENOMEM;
 
@@ -2218,10 +2193,10 @@
        pmap = pool_cache_get(&pmap_cache, PR_WAITOK);
 
        /* init uvm_object */
+       mutex_init(pmap->pm_lock, MUTEX_DEFAULT, IPL_NONE);
        for (i = 0; i < PTP_LEVELS - 1; i++) {
-               mutex_init(&pmap->pm_obj_lock[i], MUTEX_DEFAULT, IPL_NONE);
                uvm_obj_init(&pmap->pm_obj[i], NULL, false, 1);
-               uvm_obj_setlock(&pmap->pm_obj[i], &pmap->pm_obj_lock[i]);
+               uvm_obj_setlock(&pmap->pm_obj[i], pmap->pm_lock);
                pmap->pm_ptphint[i] = NULL;
        }
        pmap->pm_stats.wired_count = 0;
@@ -2393,8 +2368,8 @@
 
        for (i = 0; i < PTP_LEVELS - 1; i++) {
                uvm_obj_destroy(&pmap->pm_obj[i], false);
-               mutex_destroy(&pmap->pm_obj_lock[i]);
        }
+       mutex_destroy(pmap->pm_lock);
        pool_cache_put(&pmap_cache, pmap);
 }