From f2d03d89615ef65b5dff3aae6581df0b5fcbaa3b Mon Sep 17 00:00:00 2001 From: Lars Ellenberg Date: Tue, 22 Nov 2022 14:42:58 +0100 Subject: lru_cache: use atomic operations when accessing lc->flags, always MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Or, depending on the way locking is implemented at the call sites, some updates could be lost (has not been observed). Signed-off-by: Lars Ellenberg Signed-off-by: Christoph Böhmwalder Link: https://lore.kernel.org/r/20221122134301.69258-2-christoph.boehmwalder@linbit.com Signed-off-by: Jens Axboe --- lib/lru_cache.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'lib/lru_cache.c') diff --git a/lib/lru_cache.c b/lib/lru_cache.c index dc35464216d3..fec899386238 100644 --- a/lib/lru_cache.c +++ b/lib/lru_cache.c @@ -364,7 +364,7 @@ static struct lc_element *__lc_get(struct lru_cache *lc, unsigned int enr, unsig struct lc_element *e; PARANOIA_ENTRY(); - if (lc->flags & LC_STARVING) { + if (test_bit(__LC_STARVING, &lc->flags)) { ++lc->starving; RETURN(NULL); } @@ -417,7 +417,7 @@ static struct lc_element *__lc_get(struct lru_cache *lc, unsigned int enr, unsig * the LRU element, we have to wait ... */ if (!lc_unused_element_available(lc)) { - __set_bit(__LC_STARVING, &lc->flags); + set_bit(__LC_STARVING, &lc->flags); RETURN(NULL); } -- cgit v1.2.3 From 9933438430b3b787f96bb434b4490b0dda59c9b3 Mon Sep 17 00:00:00 2001 From: Christoph Böhmwalder Date: Tue, 22 Nov 2022 14:42:59 +0100 Subject: lru_cache: remove compiled out code MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Christoph Böhmwalder Link: https://lore.kernel.org/r/20221122134301.69258-3-christoph.boehmwalder@linbit.com Signed-off-by: Jens Axboe --- lib/lru_cache.c | 11 ----------- 1 file changed, 11 deletions(-) (limited to 'lib/lru_cache.c') diff --git a/lib/lru_cache.c b/lib/lru_cache.c index fec899386238..5dd5e4c00a23 100644 --- a/lib/lru_cache.c +++ b/lib/lru_cache.c @@ -60,17 +60,6 @@ int lc_try_lock(struct lru_cache *lc) } while (unlikely (val == LC_PARANOIA)); /* Spin until no-one is inside a PARANOIA_ENTRY()/RETURN() section. */ return 0 == val; -#if 0 - /* Alternative approach, spin in case someone enters or leaves a - * PARANOIA_ENTRY()/RETURN() section. */ - unsigned long old, new, val; - do { - old = lc->flags & LC_PARANOIA; - new = old | LC_LOCKED; - val = cmpxchg(&lc->flags, old, new); - } while (unlikely (val == (old ^ LC_PARANOIA))); - return old == val; -#endif } /** -- cgit v1.2.3 From 2cd10a496a86787367716b684dadfecbb594095b Mon Sep 17 00:00:00 2001 From: Joel Colledge Date: Tue, 22 Nov 2022 14:43:00 +0100 Subject: lru_cache: remove unused lc_private, lc_set, lc_index_of MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Joel Colledge Signed-off-by: Christoph Böhmwalder Link: https://lore.kernel.org/r/20221122134301.69258-4-christoph.boehmwalder@linbit.com Signed-off-by: Jens Axboe --- include/linux/lru_cache.h | 3 --- lib/lru_cache.c | 44 -------------------------------------------- 2 files changed, 47 deletions(-) (limited to 'lib/lru_cache.c') diff --git a/include/linux/lru_cache.h b/include/linux/lru_cache.h index 07add7882a5d..c9afcdd9324c 100644 --- a/include/linux/lru_cache.h +++ b/include/linux/lru_cache.h @@ -199,7 +199,6 @@ struct lru_cache { unsigned long flags; - void *lc_private; const char *name; /* nr_elements there */ @@ -241,7 +240,6 @@ extern struct lru_cache *lc_create(const char *name, struct kmem_cache *cache, unsigned e_count, size_t e_size, size_t e_off); extern void lc_reset(struct lru_cache *lc); extern void lc_destroy(struct lru_cache *lc); -extern void lc_set(struct lru_cache *lc, unsigned int enr, int index); extern void lc_del(struct lru_cache *lc, struct lc_element *element); extern struct lc_element *lc_get_cumulative(struct lru_cache *lc, unsigned int enr); @@ -297,6 +295,5 @@ extern bool lc_is_used(struct lru_cache *lc, unsigned int enr); container_of(ptr, type, member) extern struct lc_element *lc_element_by_index(struct lru_cache *lc, unsigned i); -extern unsigned int lc_index_of(struct lru_cache *lc, struct lc_element *e); #endif diff --git a/lib/lru_cache.c b/lib/lru_cache.c index 5dd5e4c00a23..b3d9187611de 100644 --- a/lib/lru_cache.c +++ b/lib/lru_cache.c @@ -574,48 +574,6 @@ struct lc_element *lc_element_by_index(struct lru_cache *lc, unsigned i) return lc->lc_element[i]; } -/** - * lc_index_of - * @lc: the lru cache to operate on - * @e: the element to query for its index position in lc->element - */ -unsigned int lc_index_of(struct lru_cache *lc, struct lc_element *e) -{ - PARANOIA_LC_ELEMENT(lc, e); - return e->lc_index; -} - -/** - * lc_set - associate index with label - * @lc: the lru cache to operate on - * @enr: the label to set - * @index: the element index to associate label with. - * - * Used to initialize the active set to some previously recorded state. - */ -void lc_set(struct lru_cache *lc, unsigned int enr, int index) -{ - struct lc_element *e; - struct list_head *lh; - - if (index < 0 || index >= lc->nr_elements) - return; - - e = lc_element_by_index(lc, index); - BUG_ON(e->lc_number != e->lc_new_number); - BUG_ON(e->refcnt != 0); - - e->lc_number = e->lc_new_number = enr; - hlist_del_init(&e->colision); - if (enr == LC_FREE) - lh = &lc->free; - else { - hlist_add_head(&e->colision, lc_hash_slot(lc, enr)); - lh = &lc->lru; - } - list_move(&e->list, lh); -} - /** * lc_seq_dump_details - Dump a complete LRU cache to seq in textual form. * @lc: the lru cache to operate on @@ -650,7 +608,6 @@ void lc_seq_dump_details(struct seq_file *seq, struct lru_cache *lc, char *utext EXPORT_SYMBOL(lc_create); EXPORT_SYMBOL(lc_reset); EXPORT_SYMBOL(lc_destroy); -EXPORT_SYMBOL(lc_set); EXPORT_SYMBOL(lc_del); EXPORT_SYMBOL(lc_try_get); EXPORT_SYMBOL(lc_find); @@ -658,7 +615,6 @@ EXPORT_SYMBOL(lc_get); EXPORT_SYMBOL(lc_put); EXPORT_SYMBOL(lc_committed); EXPORT_SYMBOL(lc_element_by_index); -EXPORT_SYMBOL(lc_index_of); EXPORT_SYMBOL(lc_seq_printf_stats); EXPORT_SYMBOL(lc_seq_dump_details); EXPORT_SYMBOL(lc_try_lock); -- cgit v1.2.3