Date: Tue, 27 Sep 2022 15:15:21 GMT From: Andrew Turner <andrew@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: 92d73b0b2564 - main - arm64 pmap: batch chunk removal in pmap_remove_pages Message-ID: <202209271515.28RFFLpw015534@gitrepo.freebsd.org>
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The branch main has been updated by andrew: URL: https://cgit.FreeBSD.org/src/commit/?id=92d73b0b256465adff6722a817220193b6037448 commit 92d73b0b256465adff6722a817220193b6037448 Author: Andrew Turner <andrew@FreeBSD.org> AuthorDate: 2022-08-23 09:50:18 +0000 Commit: Andrew Turner <andrew@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); }
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