Makes Dept able to track PG_locked waits and events. It's going to be useful in practice. See the following link that shows dept worked with PG_locked and can detect real issues: https://lore.kernel.org/lkml/1674268856-31807-1-git-send-email-byungchul.park@xxxxxxx/ Signed-off-by: Byungchul Park <byungchul@xxxxxx> --- include/linux/mm_types.h | 2 + include/linux/page-flags.h | 105 ++++++++++++++++++++++++++++++++----- include/linux/pagemap.h | 7 ++- mm/filemap.c | 26 +++++++++ mm/mm_init.c | 2 + 5 files changed, 129 insertions(+), 13 deletions(-) diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 957ce38768b2..5c1112bc7a46 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -19,6 +19,7 @@ #include <linux/workqueue.h> #include <linux/seqlock.h> #include <linux/percpu_counter.h> +#include <linux/dept.h> #include <asm/mmu.h> @@ -203,6 +204,7 @@ struct page { struct page *kmsan_shadow; struct page *kmsan_origin; #endif + struct dept_ext_wgen PG_locked_wgen; } _struct_page_alignment; /* diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index a88e64acebfe..0a498f2c4543 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -198,6 +198,43 @@ enum pageflags { #ifndef __GENERATING_BOUNDS_H +#ifdef CONFIG_DEPT +#include <linux/kernel.h> +#include <linux/dept.h> + +extern struct dept_map PG_locked_map; + +/* + * Place the following annotations in its suitable point in code: + * + * Annotate dept_page_set_bit() around firstly set_bit*() + * Annotate dept_page_clear_bit() around clear_bit*() + * Annotate dept_page_wait_on_bit() around wait_on_bit*() + */ + +static inline void dept_page_set_bit(struct page *p, int bit_nr) +{ + if (bit_nr == PG_locked) + dept_request_event(&PG_locked_map, &p->PG_locked_wgen); +} + +static inline void dept_page_clear_bit(struct page *p, int bit_nr) +{ + if (bit_nr == PG_locked) + dept_event(&PG_locked_map, 1UL, _RET_IP_, __func__, &p->PG_locked_wgen); +} + +static inline void dept_page_wait_on_bit(struct page *p, int bit_nr) +{ + if (bit_nr == PG_locked) + dept_wait(&PG_locked_map, 1UL, _RET_IP_, __func__, 0, -1L); +} +#else +#define dept_page_set_bit(p, bit_nr) do { } while (0) +#define dept_page_clear_bit(p, bit_nr) do { } while (0) +#define dept_page_wait_on_bit(p, bit_nr) do { } while (0) +#endif + #ifdef CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP DECLARE_STATIC_KEY_FALSE(hugetlb_optimize_vmemmap_key); @@ -379,44 +416,88 @@ static __always_inline int Page##uname(struct page *page) \ #define SETPAGEFLAG(uname, lname, policy) \ static __always_inline \ void folio_set_##lname(struct folio *folio) \ -{ set_bit(PG_##lname, folio_flags(folio, FOLIO_##policy)); } \ +{ \ + set_bit(PG_##lname, folio_flags(folio, FOLIO_##policy)); \ + dept_page_set_bit(&folio->page, PG_##lname); \ +} \ static __always_inline void SetPage##uname(struct page *page) \ -{ set_bit(PG_##lname, &policy(page, 1)->flags); } +{ \ + set_bit(PG_##lname, &policy(page, 1)->flags); \ + dept_page_set_bit(page, PG_##lname); \ +} #define CLEARPAGEFLAG(uname, lname, policy) \ static __always_inline \ void folio_clear_##lname(struct folio *folio) \ -{ clear_bit(PG_##lname, folio_flags(folio, FOLIO_##policy)); } \ +{ \ + clear_bit(PG_##lname, folio_flags(folio, FOLIO_##policy)); \ + dept_page_clear_bit(&folio->page, PG_##lname); \ +} \ static __always_inline void ClearPage##uname(struct page *page) \ -{ clear_bit(PG_##lname, &policy(page, 1)->flags); } +{ \ + clear_bit(PG_##lname, &policy(page, 1)->flags); \ + dept_page_clear_bit(page, PG_##lname); \ +} #define __SETPAGEFLAG(uname, lname, policy) \ static __always_inline \ void __folio_set_##lname(struct folio *folio) \ -{ __set_bit(PG_##lname, folio_flags(folio, FOLIO_##policy)); } \ +{ \ + __set_bit(PG_##lname, folio_flags(folio, FOLIO_##policy)); \ + dept_page_set_bit(&folio->page, PG_##lname); \ +} \ static __always_inline void __SetPage##uname(struct page *page) \ -{ __set_bit(PG_##lname, &policy(page, 1)->flags); } +{ \ + __set_bit(PG_##lname, &policy(page, 1)->flags); \ + dept_page_set_bit(page, PG_##lname); \ +} #define __CLEARPAGEFLAG(uname, lname, policy) \ static __always_inline \ void __folio_clear_##lname(struct folio *folio) \ -{ __clear_bit(PG_##lname, folio_flags(folio, FOLIO_##policy)); } \ +{ \ + __clear_bit(PG_##lname, folio_flags(folio, FOLIO_##policy)); \ + dept_page_clear_bit(&folio->page, PG_##lname); \ +} \ static __always_inline void __ClearPage##uname(struct page *page) \ -{ __clear_bit(PG_##lname, &policy(page, 1)->flags); } +{ \ + __clear_bit(PG_##lname, &policy(page, 1)->flags); \ + dept_page_clear_bit(page, PG_##lname); \ +} #define TESTSETFLAG(uname, lname, policy) \ static __always_inline \ bool folio_test_set_##lname(struct folio *folio) \ -{ return test_and_set_bit(PG_##lname, folio_flags(folio, FOLIO_##policy)); } \ +{ \ + bool ret = test_and_set_bit(PG_##lname, folio_flags(folio, FOLIO_##policy));\ + if (!ret) \ + dept_page_set_bit(&folio->page, PG_##lname); \ + return ret; \ +} \ static __always_inline int TestSetPage##uname(struct page *page) \ -{ return test_and_set_bit(PG_##lname, &policy(page, 1)->flags); } +{ \ + bool ret = test_and_set_bit(PG_##lname, &policy(page, 1)->flags);\ + if (!ret) \ + dept_page_set_bit(page, PG_##lname); \ + return ret; \ +} #define TESTCLEARFLAG(uname, lname, policy) \ static __always_inline \ bool folio_test_clear_##lname(struct folio *folio) \ -{ return test_and_clear_bit(PG_##lname, folio_flags(folio, FOLIO_##policy)); } \ +{ \ + bool ret = test_and_clear_bit(PG_##lname, folio_flags(folio, FOLIO_##policy));\ + if (ret) \ + dept_page_clear_bit(&folio->page, PG_##lname); \ + return ret; \ +} \ static __always_inline int TestClearPage##uname(struct page *page) \ -{ return test_and_clear_bit(PG_##lname, &policy(page, 1)->flags); } +{ \ + bool ret = test_and_clear_bit(PG_##lname, &policy(page, 1)->flags);\ + if (ret) \ + dept_page_clear_bit(page, PG_##lname); \ + return ret; \ +} #define PAGEFLAG(uname, lname, policy) \ TESTPAGEFLAG(uname, lname, policy) \ diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index 06142ff7f9ce..c6683b228b20 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -991,7 +991,12 @@ void folio_unlock(struct folio *folio); */ static inline bool folio_trylock(struct folio *folio) { - return likely(!test_and_set_bit_lock(PG_locked, folio_flags(folio, 0))); + bool ret = !test_and_set_bit_lock(PG_locked, folio_flags(folio, 0)); + + if (ret) + dept_page_set_bit(&folio->page, PG_locked); + + return likely(ret); } /* diff --git a/mm/filemap.c b/mm/filemap.c index ad5b4aa049a3..241a67a363b0 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -45,6 +45,7 @@ #include <linux/migrate.h> #include <linux/pipe_fs_i.h> #include <linux/splice.h> +#include <linux/dept.h> #include <asm/pgalloc.h> #include <asm/tlbflush.h> #include "internal.h" @@ -1098,6 +1099,7 @@ static int wake_page_function(wait_queue_entry_t *wait, unsigned mode, int sync, if (flags & WQ_FLAG_CUSTOM) { if (test_and_set_bit(key->bit_nr, &key->folio->flags)) return -1; + dept_page_set_bit(&key->folio->page, key->bit_nr); flags |= WQ_FLAG_DONE; } } @@ -1181,6 +1183,7 @@ static inline bool folio_trylock_flag(struct folio *folio, int bit_nr, if (wait->flags & WQ_FLAG_EXCLUSIVE) { if (test_and_set_bit(bit_nr, &folio->flags)) return false; + dept_page_set_bit(&folio->page, bit_nr); } else if (test_bit(bit_nr, &folio->flags)) return false; @@ -1191,6 +1194,9 @@ static inline bool folio_trylock_flag(struct folio *folio, int bit_nr, /* How many times do we accept lock stealing from under a waiter? */ int sysctl_page_lock_unfairness = 5; +struct dept_map __maybe_unused PG_locked_map = DEPT_MAP_INITIALIZER(PG_locked_map, NULL); +EXPORT_SYMBOL(PG_locked_map); + static inline int folio_wait_bit_common(struct folio *folio, int bit_nr, int state, enum behavior behavior) { @@ -1202,6 +1208,8 @@ static inline int folio_wait_bit_common(struct folio *folio, int bit_nr, unsigned long pflags; bool in_thrashing; + dept_page_wait_on_bit(&folio->page, bit_nr); + if (bit_nr == PG_locked && !folio_test_uptodate(folio) && folio_test_workingset(folio)) { delayacct_thrashing_start(&in_thrashing); @@ -1295,6 +1303,23 @@ static inline int folio_wait_bit_common(struct folio *folio, int bit_nr, break; } + /* + * dept_page_set_bit() might have been called already in + * folio_trylock_flag(), wake_page_function() or somewhere. + * However, call it again to reset the wgen of dept to ensure + * dept_page_wait_on_bit() is called prior to + * dept_page_set_bit(). + * + * Remind dept considers all the waits between + * dept_page_set_bit() and dept_page_clear_bit() as potential + * event disturbers. Ensure the correct sequence so that dept + * can make correct decisions: + * + * wait -> acquire(set bit) -> release(clear bit) + */ + if (wait->flags & WQ_FLAG_DONE) + dept_page_set_bit(&folio->page, bit_nr); + /* * If a signal happened, this 'finish_wait()' may remove the last * waiter from the wait-queues, but the folio waiters bit will remain @@ -1471,6 +1496,7 @@ void folio_unlock(struct folio *folio) BUILD_BUG_ON(PG_waiters != 7); BUILD_BUG_ON(PG_locked > 7); VM_BUG_ON_FOLIO(!folio_test_locked(folio), folio); + dept_page_clear_bit(&folio->page, PG_locked); if (folio_xor_flags_has_waiters(folio, 1 << PG_locked)) folio_wake_bit(folio, PG_locked); } diff --git a/mm/mm_init.c b/mm/mm_init.c index 077bfe393b5e..fc150d7a3686 100644 --- a/mm/mm_init.c +++ b/mm/mm_init.c @@ -26,6 +26,7 @@ #include <linux/pgtable.h> #include <linux/swap.h> #include <linux/cma.h> +#include <linux/dept.h> #include "internal.h" #include "slab.h" #include "shuffle.h" @@ -564,6 +565,7 @@ void __meminit __init_single_page(struct page *page, unsigned long pfn, page_mapcount_reset(page); page_cpupid_reset_last(page); page_kasan_tag_reset(page); + dept_ext_wgen_init(&page->PG_locked_wgen); INIT_LIST_HEAD(&page->lru); #ifdef WANT_PAGE_VIRTUAL -- 2.17.1
