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[src/trunk]: src/sys/arch/x86 Allocate PV entries in PAGE_SIZE chunks, and ca...
details: https://anonhg.NetBSD.org/src/rev/a102ab9bef5e
branches: trunk
changeset: 850480:a102ab9bef5e
user: ad <ad%NetBSD.org@localhost>
date: Sun Apr 05 00:21:11 2020 +0000
description:
Allocate PV entries in PAGE_SIZE chunks, and cache partially allocated PV
pages with the pmap. Worth about 2-3% sys time on build.sh for me.
diffstat:
sys/arch/x86/include/pmap.h | 5 +-
sys/arch/x86/x86/pmap.c | 267 ++++++++++++++++++++++++++++---------------
2 files changed, 175 insertions(+), 97 deletions(-)
diffs (truncated from 586 to 300 lines):
diff -r 96bfd1331486 -r a102ab9bef5e sys/arch/x86/include/pmap.h
--- a/sys/arch/x86/include/pmap.h Sat Apr 04 23:58:54 2020 +0000
+++ b/sys/arch/x86/include/pmap.h Sun Apr 05 00:21:11 2020 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: pmap.h,v 1.116 2020/03/22 00:16:16 ad Exp $ */
+/* $NetBSD: pmap.h,v 1.117 2020/04/05 00:21:11 ad Exp $ */
/*
* Copyright (c) 1997 Charles D. Cranor and Washington University.
@@ -259,6 +259,9 @@
/* pointer to a PTP in our pmap */
struct pmap_statistics pm_stats; /* pmap stats */
struct pv_entry *pm_pve; /* spare pv_entry */
+ LIST_HEAD(, pv_page) pm_pvp_part;
+ LIST_HEAD(, pv_page) pm_pvp_empty;
+ LIST_HEAD(, pv_page) pm_pvp_full;
#if !defined(__x86_64__)
vaddr_t pm_hiexec; /* highest executable mapping */
diff -r 96bfd1331486 -r a102ab9bef5e sys/arch/x86/x86/pmap.c
--- a/sys/arch/x86/x86/pmap.c Sat Apr 04 23:58:54 2020 +0000
+++ b/sys/arch/x86/x86/pmap.c Sun Apr 05 00:21:11 2020 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: pmap.c,v 1.380 2020/03/22 00:16:16 ad Exp $ */
+/* $NetBSD: pmap.c,v 1.381 2020/04/05 00:21:11 ad Exp $ */
/*
* Copyright (c) 2008, 2010, 2016, 2017, 2019, 2020 The NetBSD Foundation, Inc.
@@ -130,7 +130,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.380 2020/03/22 00:16:16 ad Exp $");
+__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.381 2020/04/05 00:21:11 ad Exp $");
#include "opt_user_ldt.h"
#include "opt_lockdebug.h"
@@ -371,9 +371,9 @@
static void pmap_dtor(void *, void *);
/*
- * pv_entry cache
+ * pv_page cache
*/
-static struct pool_cache pmap_pv_cache;
+static struct pool_cache pmap_pvp_cache;
#ifdef __HAVE_DIRECT_MAP
vaddr_t pmap_direct_base __read_mostly;
@@ -430,6 +430,20 @@
};
/*
+ * PV entries are allocated in page-sized chunks and cached per-pmap to
+ * avoid intense pressure on memory allocators.
+ */
+
+struct pv_page {
+ LIST_HEAD(, pv_entry) pvp_pves;
+ LIST_ENTRY(pv_page) pvp_list;
+ long pvp_nfree;
+ struct pmap *pvp_pmap;
+};
+
+#define PVE_PER_PVP ((PAGE_SIZE / sizeof(struct pv_entry)) - 1)
+
+/*
* PV tree prototypes
*/
@@ -472,9 +486,13 @@
static void pmap_free_ptp(struct pmap *, struct vm_page *, vaddr_t,
pt_entry_t *, pd_entry_t * const *);
static bool pmap_remove_pte(struct pmap *, struct vm_page *, pt_entry_t *,
- vaddr_t, struct pv_entry **);
+ vaddr_t);
static void pmap_remove_ptes(struct pmap *, struct vm_page *, vaddr_t, vaddr_t,
- vaddr_t, struct pv_entry **);
+ vaddr_t);
+static int pmap_pvp_ctor(void *, void *, int);
+static void pmap_pvp_dtor(void *, void *);
+static struct pv_entry *pmap_alloc_pv(struct pmap *);
+static void pmap_free_pv(struct pmap *, struct pv_entry *);
static void pmap_alloc_level(struct pmap *, vaddr_t, long *);
@@ -1837,14 +1855,9 @@
pool_init(&pmap_pdp_pool, PAGE_SIZE, 0, 0, flags,
"pdppl", NULL, IPL_NONE);
#endif
- pool_cache_bootstrap(&pmap_pv_cache, sizeof(struct pv_entry),
-#ifdef _LP64
- coherency_unit,
-#else
- coherency_unit / 2,
-#endif
- 0, PR_LARGECACHE, "pvpl", &pool_allocator_kmem,
- IPL_NONE, NULL, NULL, NULL);
+ pool_cache_bootstrap(&pmap_pvp_cache, PAGE_SIZE, PAGE_SIZE,
+ 0, 0, "pvpage", &pool_allocator_kmem,
+ IPL_NONE, pmap_pvp_ctor, pmap_pvp_dtor, NULL);
pmap_tlb_init();
@@ -1947,23 +1960,109 @@
*/
/*
- * pmap_free_pvs: free a linked list of pv entries. the pv entries have
- * been removed from their respective pages, but are still entered into the
- * map and we must undo that.
- *
- * => must be called with pmap locked.
+ * pmap_pvp_dtor: pool_cache constructor for PV pages.
+ */
+static int
+pmap_pvp_ctor(void *arg, void *obj, int flags)
+{
+ struct pv_page *pvp = (struct pv_page *)obj;
+ struct pv_entry *pve = (struct pv_entry *)obj + 1;
+ struct pv_entry *maxpve = pve + PVE_PER_PVP;
+
+ KASSERT(sizeof(struct pv_page) <= sizeof(struct pv_entry));
+ KASSERT(trunc_page((vaddr_t)obj) == (vaddr_t)obj);
+
+ LIST_INIT(&pvp->pvp_pves);
+ pvp->pvp_nfree = PVE_PER_PVP;
+ pvp->pvp_pmap = NULL;
+
+ for (; pve < maxpve; pve++) {
+ LIST_INSERT_HEAD(&pvp->pvp_pves, pve, pve_list);
+ }
+
+ return 0;
+}
+
+/*
+ * pmap_pvp_dtor: pool_cache destructor for PV pages.
*/
static void
-pmap_free_pvs(struct pmap *pmap, struct pv_entry *pve)
+pmap_pvp_dtor(void *arg, void *obj)
{
- struct pv_entry *next;
+ struct pv_page *pvp __diagused = obj;
+
+ KASSERT(pvp->pvp_pmap == NULL);
+ KASSERT(pvp->pvp_nfree == PVE_PER_PVP);
+}
+
+/*
+ * pmap_alloc_pv: allocate a PV entry (likely cached with pmap).
+ */
+static struct pv_entry *
+pmap_alloc_pv(struct pmap *pmap)
+{
+ struct pv_entry *pve;
+ struct pv_page *pvp;
KASSERT(mutex_owned(&pmap->pm_lock));
- for ( /* null */ ; pve != NULL ; pve = next) {
- next = pve->pve_next;
- pool_cache_put(&pmap_pv_cache, pve);
- }
+ if (__predict_false((pvp = LIST_FIRST(&pmap->pm_pvp_part)) == NULL)) {
+ if ((pvp = LIST_FIRST(&pmap->pm_pvp_full)) != NULL) {
+ LIST_REMOVE(pvp, pvp_list);
+ } else {
+ pvp = pool_cache_get(&pmap_pvp_cache, PR_NOWAIT);
+ }
+ if (__predict_false(pvp == NULL)) {
+ return NULL;
+ }
+ /* full -> part */
+ LIST_INSERT_HEAD(&pmap->pm_pvp_part, pvp, pvp_list);
+ pvp->pvp_pmap = pmap;
+ }
+
+ KASSERT(pvp->pvp_pmap == pmap);
+ KASSERT(pvp->pvp_nfree > 0);
+
+ pve = LIST_FIRST(&pvp->pvp_pves);
+ LIST_REMOVE(pve, pve_list);
+ pvp->pvp_nfree--;
+
+ if (__predict_false(pvp->pvp_nfree == 0)) {
+ /* part -> empty */
+ KASSERT(LIST_EMPTY(&pvp->pvp_pves));
+ LIST_REMOVE(pvp, pvp_list);
+ LIST_INSERT_HEAD(&pmap->pm_pvp_empty, pvp, pvp_list);
+ } else {
+ KASSERT(!LIST_EMPTY(&pvp->pvp_pves));
+ }
+
+ return pve;
+}
+
+/*
+ * pmap_free_pv: delayed free of a PV entry.
+ */
+static void
+pmap_free_pv(struct pmap *pmap, struct pv_entry *pve)
+{
+ struct pv_page *pvp = (struct pv_page *)trunc_page((vaddr_t)pve);
+
+ KASSERT(mutex_owned(&pmap->pm_lock));
+ KASSERT(pvp->pvp_pmap == pmap);
+ KASSERT(pvp->pvp_nfree >= 0);
+
+ LIST_INSERT_HEAD(&pvp->pvp_pves, pve, pve_list);
+ pvp->pvp_nfree++;
+
+ if (__predict_false(pvp->pvp_nfree == 1)) {
+ /* empty -> part */
+ LIST_REMOVE(pvp, pvp_list);
+ LIST_INSERT_HEAD(&pmap->pm_pvp_part, pvp, pvp_list);
+ } else if (__predict_false(pvp->pvp_nfree == PVE_PER_PVP)) {
+ /* part -> full */
+ LIST_REMOVE(pvp, pvp_list);
+ LIST_INSERT_HEAD(&pmap->pm_pvp_full, pvp, pvp_list);
+ }
}
/*
@@ -2129,7 +2228,7 @@
* case it's needed; won't know for sure until the lock is taken.
*/
if (pmap->pm_pve == NULL) {
- pmap->pm_pve = pool_cache_get(&pmap_pv_cache, PR_NOWAIT);
+ pmap->pm_pve = pmap_alloc_pv(pmap);
}
error = 0;
@@ -2171,7 +2270,7 @@
* pmap_remove_pv: try to remove a mapping from a pv_list
*
* => pmap must be locked
- * => removes dynamic entries from tree
+ * => removes dynamic entries from tree and frees them
* => caller should adjust ptp's wire_count and free PTP if needed
*/
static void
@@ -2213,6 +2312,7 @@
#ifdef DIAGNOSTIC
memset(pve, 0, sizeof(*pve));
#endif
+ pmap_free_pv(pmap, pve);
}
KASSERT(pmap_treelookup_pv(pmap, ptp, tree, va) == NULL);
@@ -2670,6 +2770,9 @@
#endif
LIST_INIT(&pmap->pm_gc_ptp);
pmap->pm_pve = NULL;
+ LIST_INIT(&pmap->pm_pvp_full);
+ LIST_INIT(&pmap->pm_pvp_part);
+ LIST_INIT(&pmap->pm_pvp_empty);
/* allocate and init PDP */
pmap->pm_pdir = pool_get(&pmap_pdp_pool, PR_WAITOK);
@@ -2702,10 +2805,6 @@
{
struct pmap *pmap = obj;
- if (pmap->pm_pve != NULL) {
- pool_cache_put(&pmap_pv_cache, pmap->pm_pve);
- }
-
mutex_enter(&pmaps_lock);
LIST_REMOVE(pmap, pm_list);
mutex_exit(&pmaps_lock);
@@ -2832,13 +2931,16 @@
pmap_check_inuse(pmap);
/*
- * XXX handle deferred PTP page free for EPT. ordinarily this is
- * taken care of by pmap_remove_all(). once shared with EPT this
- * can go away.
+ * handle any deferred frees.
*/
- if (__predict_false(!LIST_EMPTY(&pmap->pm_gc_ptp))) {
- pmap_update(pmap);
- }
+
+ if (pmap->pm_pve != NULL) {
+ mutex_enter(&pmap->pm_lock);
+ pmap_free_pv(pmap, pmap->pm_pve);
+ mutex_exit(&pmap->pm_lock);
+ pmap->pm_pve = NULL;
+ }
+ pmap_update(pmap);
/*
* Reference count is zero, free pmap resources and then free pmap.
@@ -2874,6 +2976,10 @@
kcpuset_zero(pmap->pm_xen_ptp_cpus);
#endif
+ KASSERT(LIST_EMPTY(&pmap->pm_pvp_full));
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