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X-AuditID: a67dfc5b-d85ff70000001748-6b-64a299b4c184 From: Byungchul Park To: linux-kernel@vger.kernel.org Cc: kernel_team@skhynix.com, torvalds@linux-foundation.org, damien.lemoal@opensource.wdc.com, linux-ide@vger.kernel.org, adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org, mingo@redhat.com, peterz@infradead.org, will@kernel.org, tglx@linutronix.de, rostedt@goodmis.org, joel@joelfernandes.org, sashal@kernel.org, daniel.vetter@ffwll.ch, duyuyang@gmail.com, johannes.berg@intel.com, tj@kernel.org, tytso@mit.edu, willy@infradead.org, david@fromorbit.com, amir73il@gmail.com, gregkh@linuxfoundation.org, kernel-team@lge.com, linux-mm@kvack.org, akpm@linux-foundation.org, mhocko@kernel.org, minchan@kernel.org, hannes@cmpxchg.org, vdavydov.dev@gmail.com, sj@kernel.org, jglisse@redhat.com, dennis@kernel.org, cl@linux.com, penberg@kernel.org, rientjes@google.com, vbabka@suse.cz, ngupta@vflare.org, linux-block@vger.kernel.org, josef@toxicpanda.com, linux-fsdevel@vger.kernel.org, viro@zeniv.linux.org.uk, jack@suse.cz, jlayton@kernel.org, dan.j.williams@intel.com, hch@infradead.org, djwong@kernel.org, dri-devel@lists.freedesktop.org, rodrigosiqueiramelo@gmail.com, melissa.srw@gmail.com, hamohammed.sa@gmail.com, 42.hyeyoo@gmail.com, chris.p.wilson@intel.com, gwan-gyeong.mun@intel.com, max.byungchul.park@gmail.com, boqun.feng@gmail.com, longman@redhat.com, hdanton@sina.com, her0gyugyu@gmail.com Subject: [PATCH v10 rebased on v6.4 25/25] dept: Track the potential waits of PG_{locked,writeback} Date: Mon, 3 Jul 2023 18:47:52 +0900 Message-Id: <20230703094752.79269-26-byungchul@sk.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20230703094752.79269-1-byungchul@sk.com> References: <20230703094752.79269-1-byungchul@sk.com> X-Brightmail-Tracker: H4sIAAAAAAAAAzWSbUxTZxiGfc/Hew7FmrNq9Kg/po0MUzIFI/rEODXR6JsYE42JJjqj1Z7Y ZoDaIoofsVoUrYJg5EsQKc6uaTvBgqZTwA4URaJUQS0EiBAEG760rISvTSlmf55cue/c16+H pxVudh6vS0iU9AnqOCWWMbL+6Zaf7+cVa6J9xoWQeSUagv9cZKCgxInBe9eBwFl+lgL/003w 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H4sIAAAAAAAAAzWSa0iTYRiGe9/vNFeLryX0UVEx6GxmmPaAYRGVL4HVDymKoEb7yOGcspVp UVhT85CHWWqmmdOYonaa0mlpQ1Ez8VAzM1PJdVI8lTpxaQc1+vNwcd/c169HQslzmKUStfa0 qNMqNQpWSkv3+xk2VWQXqLxSx73BeNULnOPxNOTeL2Oh9V4pgrKKSxj6awPg3cQggqmmFgqy MloRmHq7Kaio60FQWXyZBfvnhdDmHGGhISOJBUPhfRZeD0xj6MpMx1BqCYTGtAIMNtc3GrL6 WcjJMuCZ04fBZS7hwBy9GhzFNzmY7t0CDT3tDNTcamCgsnMjZOd1sfC8soGGuicODPZnuSz0 lP1hoLHuJQ2txmQG7g4XsDAwYabA7Bzh4I0tH8ODmBlb3NhvBuqTbRji7jzE0PbeiqAq/iMG S1k7CzXOQQzllgwKfhbVInCkDHEQe9XFQc6lFARJsZk0tPyqZyCmywemJnPZnX6kZnCEIjHl Z0nlRD5NXhUI5OnNbo7EVHVyJN9yhpQXbyCFz/sxMY06GWIpSWCJZTSdI4lDbZgMNzdz5OWN KZp8bsvCB5cflW5XiRp1hKjb7H9CGvwu8VB49+HIsTzfaHSDJCI3icBvFd6PpnKzzPJrhY4O FzXL7vwqoTz5K5OIpBKKvzJfKP7exM4Wi/mTgsk2PDeg+dVClfX7HMt4X+GZfYz5J10plD6w zYncZvIvkyloluW8j9CV3cOmIWk+mleC3NXaiFClWuPjqQ8JjtKqIz1PhoVa0MzLmC9MG5+g cXtANeIlSLFA1nHepJIzygh9VGg1EiSUwl1m6L2tkstUyqhzoi7suO6MRtRXo2USWrFEtu+w eELOn1KeFkNEMVzU/W+xxG1pNDricXH3nseu2rg1CZ3dfS/q431/HDfXmUiRdVeNMPRoYJu3 wvg2Muit3ZFRmrAoemIFSa0/1Woscnj7EQ+PuLPXA7E6hB9qWrj+wLrhyL5fj0ZeHcu+vVG7 ffneTzs0tH+sq/FDs7/sTmbarjef1gZ6BJgHPYMMk4esP661i4vNVgWtD1Zu2UDp9Mq/vizu 8S4DAAA= X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Currently, Dept only tracks the real waits of PG_{locked,writeback} that actually happened having gone through __schedule() to avoid false positives. However, it ends in limited capacity for deadlock detection, because anyway there might be still way more potential dependencies by the waits that have yet to happen but may happen in the future so as to cause a deadlock. So let Dept assume that when PG_{locked,writeback} bit gets cleared, there might be waits on the bit to be woken up. Even though false positives may increase with the aggressive tracking, it's worth doing it because it's going to be useful in practice. See the following link for instance: https://lore.kernel.org/lkml/1674268856-31807-1-git-send-email-byungchul.park@lge.com/ Signed-off-by: Byungchul Park --- include/linux/mm_types.h | 3 + include/linux/page-flags.h | 112 +++++++++++++++++++++++++++++++++---- include/linux/pagemap.h | 7 ++- mm/filemap.c | 11 +++- mm/mm_init.c | 3 + 5 files changed, 121 insertions(+), 15 deletions(-) diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 306a3d1a0fa6..ac5048b66e5c 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -19,6 +19,7 @@ #include #include #include +#include #include @@ -228,6 +229,8 @@ struct page { #ifdef LAST_CPUPID_NOT_IN_PAGE_FLAGS int _last_cpupid; #endif + struct dept_ext_wgen PG_locked_wgen; + struct dept_ext_wgen PG_writeback_wgen; } _struct_page_alignment; /* diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index 92a2063a0a23..d91e67ed194c 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -196,6 +196,50 @@ enum pageflags { #ifndef __GENERATING_BOUNDS_H +#ifdef CONFIG_DEPT +#include +#include + +extern struct dept_map PG_locked_map; +extern struct dept_map PG_writeback_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); + else if (bit_nr == PG_writeback) + dept_request_event(&PG_writeback_map, &p->PG_writeback_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); + else if (bit_nr == PG_writeback) + dept_event(&PG_writeback_map, 1UL, _RET_IP_, __func__, &p->PG_writeback_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 if (bit_nr == PG_writeback) + dept_wait(&PG_writeback_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); @@ -377,44 +421,88 @@ 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 a56308a9d1a4..a88e2430f415 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -915,7 +915,12 @@ 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 eed64dc88e43..f05208bb50dc 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1101,6 +1101,7 @@ 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; } } @@ -1210,6 +1211,7 @@ 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; @@ -1220,8 +1222,10 @@ 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; -static struct dept_map __maybe_unused PG_locked_map = DEPT_MAP_INITIALIZER(PG_locked_map, NULL); -static struct dept_map __maybe_unused PG_writeback_map = DEPT_MAP_INITIALIZER(PG_writeback_map, NULL); +struct dept_map __maybe_unused PG_locked_map = DEPT_MAP_INITIALIZER(PG_locked_map, NULL); +struct dept_map __maybe_unused PG_writeback_map = DEPT_MAP_INITIALIZER(PG_writeback_map, NULL); +EXPORT_SYMBOL(PG_locked_map); +EXPORT_SYMBOL(PG_writeback_map); static inline int folio_wait_bit_common(struct folio *folio, int bit_nr, int state, enum behavior behavior) @@ -1234,6 +1238,7 @@ 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) sdt_might_sleep_start(&PG_locked_map); else if (bit_nr == PG_writeback) @@ -1331,6 +1336,7 @@ static inline int folio_wait_bit_common(struct folio *folio, int bit_nr, wait->flags |= WQ_FLAG_DONE; break; } + dept_page_set_bit(&folio->page, bit_nr); /* * If a signal happened, this 'finish_wait()' may remove the last @@ -1538,6 +1544,7 @@ 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 (clear_bit_unlock_is_negative_byte(PG_locked, folio_flags(folio, 0))) folio_wake_bit(folio, PG_locked); } diff --git a/mm/mm_init.c b/mm/mm_init.c index 7f7f9c677854..a339f0cbe1b2 100644 --- a/mm/mm_init.c +++ b/mm/mm_init.c @@ -26,6 +26,7 @@ #include #include #include +#include #include "internal.h" #include "slab.h" #include "shuffle.h" @@ -558,6 +559,8 @@ static 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); + dept_ext_wgen_init(&page->PG_writeback_wgen); INIT_LIST_HEAD(&page->lru); #ifdef WANT_PAGE_VIRTUAL