The branch main has been updated by andrew:
URL:
https://cgit.FreeBSD.org/src/commit/?id=92d73b0b256465adff6722a817220193b6037448
commit 92d73b0b256465adff6722a817220193b6037448
Author: Andrew Turner <and...@freebsd.org>
AuthorDate: 2022-08-23 09:50:18 +0000
Commit: Andrew Turner <and...@freebsd.org>
CommitDate: 2022-09-27 15:03:08 +0000
arm64 pmap: batch chunk removal in pmap_remove_pages
As with amd64 batch chunk removal in pmap_remove_pages to move it out
of the pv list lock. This is one of the main contested locks when
running poudriere on a 160 core Ampere Altra server.
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D36305
---
sys/arm64/arm64/pmap.c | 41 ++++++++++++++++++++++++++++++++++++-----
1 file changed, 36 insertions(+), 5 deletions(-)
diff --git a/sys/arm64/arm64/pmap.c b/sys/arm64/arm64/pmap.c
index dce52034f27c..0c2f623aa9a3 100644
--- a/sys/arm64/arm64/pmap.c
+++ b/sys/arm64/arm64/pmap.c
@@ -380,7 +380,10 @@ SYSCTL_INT(_vm_pmap, OID_AUTO, superpages_enabled,
#define PMAP_ENTER_NORECLAIM 0x1000000 /* Don't reclaim PV
entries. */
#define PMAP_ENTER_NOREPLACE 0x2000000 /* Don't replace
mappings. */
+TAILQ_HEAD(pv_chunklist, pv_chunk);
+
static void free_pv_chunk(struct pv_chunk *pc);
+static void free_pv_chunk_batch(struct pv_chunklist *batch);
static void free_pv_entry(pmap_t pmap, pv_entry_t pv);
static pv_entry_t get_pv_entry(pmap_t pmap, struct rwlock **lockp);
static vm_page_t reclaim_pv_chunk(pmap_t locked_pmap, struct rwlock **lockp);
@@ -2756,13 +2759,10 @@ free_pv_entry(pmap_t pmap, pv_entry_t pv)
}
static void
-free_pv_chunk(struct pv_chunk *pc)
+free_pv_chunk_dequeued(struct pv_chunk *pc)
{
vm_page_t m;
- mtx_lock(&pv_chunks_mutex);
- TAILQ_REMOVE(&pv_chunks, pc, pc_lru);
- mtx_unlock(&pv_chunks_mutex);
PV_STAT(atomic_subtract_int(&pv_entry_spare, _NPCPV));
PV_STAT(atomic_subtract_int(&pc_chunk_count, 1));
PV_STAT(atomic_add_int(&pc_chunk_frees, 1));
@@ -2773,6 +2773,34 @@ free_pv_chunk(struct pv_chunk *pc)
vm_page_free(m);
}
+static void
+free_pv_chunk(struct pv_chunk *pc)
+{
+ mtx_lock(&pv_chunks_mutex);
+ TAILQ_REMOVE(&pv_chunks, pc, pc_lru);
+ mtx_unlock(&pv_chunks_mutex);
+ free_pv_chunk_dequeued(pc);
+}
+
+static void
+free_pv_chunk_batch(struct pv_chunklist *batch)
+{
+ struct pv_chunk *pc, *npc;
+
+ if (TAILQ_EMPTY(batch))
+ return;
+
+ mtx_lock(&pv_chunks_mutex);
+ TAILQ_FOREACH(pc, batch, pc_list) {
+ TAILQ_REMOVE(&pv_chunks, pc, pc_lru);
+ }
+ mtx_unlock(&pv_chunks_mutex);
+
+ TAILQ_FOREACH_SAFE(pc, batch, pc_list, npc) {
+ free_pv_chunk_dequeued(pc);
+ }
+}
+
/*
* Returns a new PV entry, allocating a new PV chunk from the system when
* needed. If this PV chunk allocation fails and a PV list lock pointer was
@@ -5248,6 +5276,7 @@ pmap_remove_pages(pmap_t pmap)
pd_entry_t *pde;
pt_entry_t *pte, tpte;
struct spglist free;
+ struct pv_chunklist free_chunks;
vm_page_t m, ml3, mt;
pv_entry_t pv;
struct md_page *pvh;
@@ -5260,6 +5289,7 @@ pmap_remove_pages(pmap_t pmap)
lock = NULL;
+ TAILQ_INIT(&free_chunks);
SLIST_INIT(&free);
PMAP_LOCK(pmap);
TAILQ_FOREACH_SAFE(pc, &pmap->pm_pvchunk, pc_list, npc) {
@@ -5400,12 +5430,13 @@ pmap_remove_pages(pmap_t pmap)
PV_STAT(atomic_subtract_long(&pv_entry_count, freed));
if (allfree) {
TAILQ_REMOVE(&pmap->pm_pvchunk, pc, pc_list);
- free_pv_chunk(pc);
+ TAILQ_INSERT_TAIL(&free_chunks, pc, pc_list);
}
}
if (lock != NULL)
rw_wunlock(lock);
pmap_invalidate_all(pmap);
+ free_pv_chunk_batch(&free_chunks);
PMAP_UNLOCK(pmap);
vm_page_free_pages_toq(&free, true);
}
