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Fri, 21 Apr 2023 10:14:35 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id 6KUrHgtiQmRNaAAAMHmgww (envelope-from ); Fri, 21 Apr 2023 10:14:35 +0000 From: Oscar Salvador To: Andrew Morton Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Michal Hocko , Vlastimil Babka , Eric Dumazet , Waiman Long , Suren Baghdasaryan , Marco Elver , Andrey Konovalov , Alexander Potapenko , Oscar Salvador Subject: [PATCH v4 1/3] lib/stackdepot: Add a refcount field in stack_record Date: Fri, 21 Apr 2023 12:14:13 +0200 Message-Id: <20230421101415.5734-2-osalvador@suse.de> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230421101415.5734-1-osalvador@suse.de> References: <20230421101415.5734-1-osalvador@suse.de> MIME-Version: 1.0 X-Rspam-User: X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 84E381C0013 X-Stat-Signature: 633y7m6p9dtss91uqap8fc9tp4usji1r X-HE-Tag: 1682072077-185258 X-HE-Meta: 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 09Ru3/h+ 0PffRQYqCc6Gh4NWpwqO2sfbYHBv/9P/Pby2oMQRtbVxyvtjvBqjc/TswygcuqwO1uPz8tX/AiAE7uhkXbZVoOc+RL6LG+ejojT0oTrT/7Qc1LyIn0zO04M9LKNu/m1iWkhRlrCcyHPOfs7uC9Wy30F/QEh/qeM+8TFuA6P6RVy7zG/dJsbDroR0xcqaABYVs6sVHMXTwSwEi7iaOtidSzLFWjFaAvpSmxsR9saA2ZiEV4+bl81MFZz17zK7lmBW0fkPf X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: We want to filter out page_owner output and print only those stacks that have been repeated beyond a certain threshold. This gives us the chance to get rid of a lot of noise. In order to do that, we need to keep track of how many repeated stacks (for allocation) do we have, so we add a new refcount_t field in the stack_record struct. Note that this might increase the size of the struct for some architectures. E.g: x86_64 is not affected due to alignment, but x86 32bits might. The alternative would be to have some kind of struct like this: struct track_stacks { struct stack_record *stack; struct track_stacks *next; refcount_t stack_count; But ithat would imply to perform more allocations and glue everything together, which would make the code more complex, so I think that going with a new field in the struct stack_record is good enough. Note that on __set_page_owner_handle(), page_owner->handle is set, and on __reset_page_owner(), page_owner->free_handle is set. We are interested in page_owner->handle, so when __set_page_owner() gets called, we derive the stack_record struct from page_owner->handle, and we increment its refcount_t field; and when __reset_page_owner() gets called, we derive its stack_record from page_owner->handle() and we decrement its refcount_t field. Signed-off-by: Oscar Salvador --- include/linux/stackdepot.h | 8 ++++- lib/stackdepot.c | 72 ++++++++++++++++++++++++++++++++------ mm/kasan/common.c | 3 +- mm/page_owner.c | 13 ++++--- 4 files changed, 79 insertions(+), 17 deletions(-) diff --git a/include/linux/stackdepot.h b/include/linux/stackdepot.h index e58306783d8e..b94d33312839 100644 --- a/include/linux/stackdepot.h +++ b/include/linux/stackdepot.h @@ -93,7 +93,9 @@ static inline int stack_depot_early_init(void) { return 0; } */ depot_stack_handle_t __stack_depot_save(unsigned long *entries, unsigned int nr_entries, - gfp_t gfp_flags, bool can_alloc); + gfp_t gfp_flags, bool can_alloc, + bool counter); +void stack_depot_dec_count(depot_stack_handle_t handle); /** * stack_depot_save - Save a stack trace to stack depot @@ -109,6 +111,10 @@ depot_stack_handle_t __stack_depot_save(unsigned long *entries, */ depot_stack_handle_t stack_depot_save(unsigned long *entries, unsigned int nr_entries, gfp_t gfp_flags); +depot_stack_handle_t stack_depot_save_action(unsigned long *entries, + unsigned int nr_entries, + gfp_t gfp_flags, + bool counter); /** * stack_depot_fetch - Fetch a stack trace from stack depot diff --git a/lib/stackdepot.c b/lib/stackdepot.c index 036da8e295d1..e99f4ef218ef 100644 --- a/lib/stackdepot.c +++ b/lib/stackdepot.c @@ -59,6 +59,7 @@ struct stack_record { u32 hash; /* Hash in the hash table */ u32 size; /* Number of stored frames */ union handle_parts handle; + refcount_t count; /* Number of the same repeated stacks */ unsigned long entries[]; /* Variable-sized array of frames */ }; @@ -304,6 +305,7 @@ depot_alloc_stack(unsigned long *entries, int size, u32 hash, void **prealloc) stack->handle.offset = pool_offset >> DEPOT_STACK_ALIGN; stack->handle.valid = 1; stack->handle.extra = 0; + refcount_set(&stack->count, 1); memcpy(stack->entries, entries, flex_array_size(stack, entries, size)); pool_offset += required_size; @@ -349,9 +351,15 @@ static inline struct stack_record *find_stack(struct stack_record *bucket, return NULL; } +static void stack_depot_inc_count(struct stack_record *stack) +{ + refcount_inc(&stack->count); +} + depot_stack_handle_t __stack_depot_save(unsigned long *entries, unsigned int nr_entries, - gfp_t alloc_flags, bool can_alloc) + gfp_t alloc_flags, bool can_alloc, + bool counter) { struct stack_record *found = NULL, **bucket; union handle_parts retval = { .handle = 0 }; @@ -436,8 +444,11 @@ depot_stack_handle_t __stack_depot_save(unsigned long *entries, /* Stack depot didn't use this memory, free it. */ free_pages((unsigned long)prealloc, DEPOT_POOL_ORDER); } - if (found) + if (found) { retval.handle = found->handle.handle; + if (counter) + stack_depot_inc_count(found); + } fast_exit: return retval.handle; } @@ -447,12 +458,20 @@ depot_stack_handle_t stack_depot_save(unsigned long *entries, unsigned int nr_entries, gfp_t alloc_flags) { - return __stack_depot_save(entries, nr_entries, alloc_flags, true); + return __stack_depot_save(entries, nr_entries, alloc_flags, true, false); } EXPORT_SYMBOL_GPL(stack_depot_save); -unsigned int stack_depot_fetch(depot_stack_handle_t handle, - unsigned long **entries) +depot_stack_handle_t stack_depot_save_action(unsigned long *entries, + unsigned int nr_entries, + gfp_t alloc_flags, + bool counter) +{ + return __stack_depot_save(entries, nr_entries, alloc_flags, true, counter); +} +EXPORT_SYMBOL_GPL(stack_depot_save_action); + +static struct stack_record *stack_depot_getstack(depot_stack_handle_t handle) { union handle_parts parts = { .handle = handle }; /* @@ -464,25 +483,56 @@ unsigned int stack_depot_fetch(depot_stack_handle_t handle, size_t offset = parts.offset << DEPOT_STACK_ALIGN; struct stack_record *stack; - *entries = NULL; - if (!handle) - return 0; + if(!handle) + return NULL; if (parts.pool_index > pool_index_cached) { WARN(1, "pool index %d out of bounds (%d) for stack id %08x\n", - parts.pool_index, pool_index_cached, handle); - return 0; + parts.pool_index, pool_index_cached, handle); + return NULL; } pool = stack_pools[parts.pool_index]; if (!pool) - return 0; + return NULL; + stack = pool + offset; + return stack; +} + +unsigned int stack_depot_fetch(depot_stack_handle_t handle, + unsigned long **entries) +{ + struct stack_record *stack; + + *entries = NULL; + if (!handle) + return 0; + + stack = stack_depot_getstack(handle); + if (!stack) + return 0; *entries = stack->entries; return stack->size; } EXPORT_SYMBOL_GPL(stack_depot_fetch); +void stack_depot_dec_count(depot_stack_handle_t handle) +{ + struct stack_record *stack = NULL; + + stack = stack_depot_getstack(handle); + if (stack) { + /* + * page_owner creates some stacks via create_dummy_stack(). + * We are not interested in those, so make sure we only decrement + * "valid" stacks. + */ + if (refcount_read(&stack->count) > 1) + refcount_dec(&stack->count); + } +} + void stack_depot_print(depot_stack_handle_t stack) { unsigned long *entries; diff --git a/mm/kasan/common.c b/mm/kasan/common.c index b376a5d055e5..ea0061ea8ae9 100644 --- a/mm/kasan/common.c +++ b/mm/kasan/common.c @@ -43,7 +43,8 @@ depot_stack_handle_t kasan_save_stack(gfp_t flags, bool can_alloc) unsigned int nr_entries; nr_entries = stack_trace_save(entries, ARRAY_SIZE(entries), 0); - return __stack_depot_save(entries, nr_entries, flags, can_alloc); + return __stack_depot_save(entries, nr_entries, flags, can_alloc, + false); } void kasan_set_track(struct kasan_track *track, gfp_t flags) diff --git a/mm/page_owner.c b/mm/page_owner.c index 220cdeddc295..b6637524e442 100644 --- a/mm/page_owner.c +++ b/mm/page_owner.c @@ -107,7 +107,7 @@ static inline struct page_owner *get_page_owner(struct page_ext *page_ext) return (void *)page_ext + page_owner_ops.offset; } -static noinline depot_stack_handle_t save_stack(gfp_t flags) +static noinline depot_stack_handle_t save_stack(gfp_t flags, bool counter) { unsigned long entries[PAGE_OWNER_STACK_DEPTH]; depot_stack_handle_t handle; @@ -126,7 +126,7 @@ static noinline depot_stack_handle_t save_stack(gfp_t flags) current->in_page_owner = 1; nr_entries = stack_trace_save(entries, ARRAY_SIZE(entries), 2); - handle = stack_depot_save(entries, nr_entries, flags); + handle = stack_depot_save_action(entries, nr_entries, flags, counter); if (!handle) handle = failure_handle; @@ -139,6 +139,7 @@ void __reset_page_owner(struct page *page, unsigned short order) int i; struct page_ext *page_ext; depot_stack_handle_t handle; + depot_stack_handle_t alloc_handle; struct page_owner *page_owner; u64 free_ts_nsec = local_clock(); @@ -146,7 +147,10 @@ void __reset_page_owner(struct page *page, unsigned short order) if (unlikely(!page_ext)) return; - handle = save_stack(GFP_NOWAIT | __GFP_NOWARN); + page_owner = get_page_owner(page_ext); + alloc_handle = page_owner->handle; + + handle = save_stack(GFP_NOWAIT | __GFP_NOWARN, false); for (i = 0; i < (1 << order); i++) { __clear_bit(PAGE_EXT_OWNER_ALLOCATED, &page_ext->flags); page_owner = get_page_owner(page_ext); @@ -155,6 +159,7 @@ void __reset_page_owner(struct page *page, unsigned short order) page_ext = page_ext_next(page_ext); } page_ext_put(page_ext); + stack_depot_dec_count(alloc_handle); } static inline void __set_page_owner_handle(struct page_ext *page_ext, @@ -189,7 +194,7 @@ noinline void __set_page_owner(struct page *page, unsigned short order, struct page_ext *page_ext; depot_stack_handle_t handle; - handle = save_stack(gfp_mask); + handle = save_stack(gfp_mask, true); page_ext = page_ext_get(page); if (unlikely(!page_ext)) From patchwork Fri Apr 21 10:14:14 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oscar Salvador X-Patchwork-Id: 13219768 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 394E4C77B78 for ; Fri, 21 Apr 2023 10:14:42 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id B72556B0074; Fri, 21 Apr 2023 06:14:41 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B24936B0075; Fri, 21 Apr 2023 06:14:41 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 94E976B0078; Fri, 21 Apr 2023 06:14:41 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id 864786B0074 for ; 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Fri, 21 Apr 2023 10:14:37 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id GNpvEQ1iQmRNaAAAMHmgww (envelope-from ); Fri, 21 Apr 2023 10:14:37 +0000 From: Oscar Salvador To: Andrew Morton Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Michal Hocko , Vlastimil Babka , Eric Dumazet , Waiman Long , Suren Baghdasaryan , Marco Elver , Andrey Konovalov , Alexander Potapenko , Oscar Salvador Subject: [PATCH v4 2/3] mm, page_owner: Add page_owner_stacks file to print out only stacks and their counte Date: Fri, 21 Apr 2023 12:14:14 +0200 Message-Id: <20230421101415.5734-3-osalvador@suse.de> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230421101415.5734-1-osalvador@suse.de> References: <20230421101415.5734-1-osalvador@suse.de> MIME-Version: 1.0 X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 5083440017 X-Stat-Signature: 5t1e7zs6dqf7re56tkzc5yinj7zru5xu X-Rspam-User: X-HE-Tag: 1682072079-570274 X-HE-Meta: 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 3+vIdJvK tgG7u/IdCN7mxqCc7MOoAoKI4rvGPhY1VJE0KXWUzoUk/r2IQMw54spRszCESfDCbf+qPA1+/BSLFPQBuZwrmv4L9ewLTdqDwppGvVW02m+f9yBPFJSGx+n3Y0YABwn9T1zYlxq/5BKQmPAhMtgLRA8rHVaHVJf6M3WY/EqmWso5GZwiJDx+2et+pgd4L5im9EL7TuspR3NlBo2Jr0s13GiDOzgDf0d1POqLPi83hUOXjCBO1NwOD46ePlKF4LUdR8i5l X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: We might be only interested in knowing about stacks <-> count relationship, so instead of having to fiddle with page_owner output and screen through pfns, let us add a new file called 'page_owner_stacks' that does just that. By cating such file, we will get all the stacktraces followed by its counter, so we can have a more global view. Signed-off-by: Oscar Salvador #include #include +#include +#include #define DEPOT_HANDLE_BITS (sizeof(depot_stack_handle_t) * 8) @@ -499,6 +501,77 @@ static struct stack_record *stack_depot_getstack(depot_stack_handle_t handle) return stack; } +#ifdef CONFIG_PAGE_OWNER +void *stack_start(struct seq_file *m, loff_t *ppos) +{ + unsigned long *table = m->private; + struct stack_record **stacks, *stack; + + /* First time */ + if (*ppos == 0) + *table = 0; + + if (*ppos == -1UL) + return NULL; + + stacks = &stack_table[*table]; + stack = (struct stack_record *)stacks; + + return stack; +} + +void *stack_next(struct seq_file *m, void *v, loff_t *ppos) +{ + unsigned long *table = m->private; + unsigned long nr_table = *table; + struct stack_record *next = NULL, *stack = v, **stacks; + unsigned long stack_table_entries = stack_hash_mask + 1; + + if (!stack) { +new_table: + /* New table */ + nr_table++; + if (nr_table >= stack_table_entries) + goto out; + stacks = &stack_table[nr_table]; + stack = (struct stack_record *)stacks; + next = stack; + } else { + next = stack->next; + } + + if (!next) + goto new_table; + +out: + *table = nr_table; + *ppos = (nr_table >= stack_table_entries) ? -1UL : *ppos + 1; + return next; +} + +int stack_print(struct seq_file *m, void *v) +{ + char *buf; + int ret = 0; + struct stack_record *stack =v; + + if (!stack->size || stack->size < 0 || + stack->size > PAGE_SIZE || stack->handle.valid != 1 || + refcount_read(&stack->count) < 1) + return 0; + + buf = kzalloc(PAGE_SIZE, GFP_KERNEL); + ret += stack_trace_snprint(buf, PAGE_SIZE, stack->entries, stack->size, 0); + scnprintf(buf + ret, PAGE_SIZE - ret, "stack count: %d\n\n", + refcount_read(&stack->count)); + seq_printf(m, buf); + seq_puts(m, "\n\n"); + kfree(buf); + + return 0; +} +#endif + unsigned int stack_depot_fetch(depot_stack_handle_t handle, unsigned long **entries) { diff --git a/mm/page_owner.c b/mm/page_owner.c index b6637524e442..b191ad1d41f9 100644 --- a/mm/page_owner.c +++ b/mm/page_owner.c @@ -718,6 +718,31 @@ static const struct file_operations proc_page_owner_operations = { .llseek = lseek_page_owner, }; +static void stack_stop(struct seq_file *m, void *v) +{ + return; +} + +static const struct seq_operations page_owner_stack_op = { + .start = stack_start, + .next = stack_next, + .stop = stack_stop, + .show = stack_print +}; + +static int page_owner_stack_open(struct inode *inode, struct file *file) +{ + return seq_open_private(file, &page_owner_stack_op, + sizeof(unsigned long)); +} + +const struct file_operations page_owner_stack_operations = { + .open = page_owner_stack_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release, +}; + static int __init pageowner_init(void) { if (!static_branch_unlikely(&page_owner_inited)) { @@ -728,6 +753,9 @@ static int __init pageowner_init(void) debugfs_create_file("page_owner", 0400, NULL, NULL, &proc_page_owner_operations); + debugfs_create_file("page_owner_stacks", S_IRUSR, NULL, NULL, + &page_owner_stack_operations); + return 0; } late_initcall(pageowner_init) From patchwork Fri Apr 21 10:14:15 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oscar Salvador X-Patchwork-Id: 13219769 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 12A43C77B75 for ; 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Fri, 21 Apr 2023 10:14:38 +0000 From: Oscar Salvador To: Andrew Morton Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Michal Hocko , Vlastimil Babka , Eric Dumazet , Waiman Long , Suren Baghdasaryan , Marco Elver , Andrey Konovalov , Alexander Potapenko , Oscar Salvador Subject: [PATCH v4 3/3] mm,page_owner: Filter out stacks by a threshold counter Date: Fri, 21 Apr 2023 12:14:15 +0200 Message-Id: <20230421101415.5734-4-osalvador@suse.de> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230421101415.5734-1-osalvador@suse.de> References: <20230421101415.5734-1-osalvador@suse.de> MIME-Version: 1.0 X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: 4C1E11C0013 X-Rspam-User: X-Stat-Signature: qedhtziuae4u7w4t3e6kfhf4sx83int5 X-HE-Tag: 1682072081-254514 X-HE-Meta: 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 WNjHQ4te RvH2kOJzVkKwNyPabcChPlJ/xpu1jWhr/cRLiF2GD50J7kpArRD8ON18j6QXOiX9LwmFVloToV7l5/Ejcdek3/eZRBeVkit+OzzWcymz6fei7oil9yBnB+GkYzVGMHOMS5acb758/ivfJthba0OlvdSyIsJI99WQl5K+cJSfwgCpEClKHkXulDMveuqg7gPqTJ+XPrmtcSb5bke2bptGnAJcW2SJmWDLvzyO7TD0NQMS5gZFXmeUq+goIGdzHxX7Pysev X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: We want to be able to filter out the output on a threshold basis, in this way we can get rid of a lot of noise and focus only on those stacks which have an allegedly high counter. We can control the threshold value by a new file called 'page_owner_threshold', which is 0 by default. Signed-off-by: Oscar Salvador --- include/linux/stackdepot.h | 3 +++ lib/stackdepot.c | 17 ++++++++++++++++- mm/page_owner.c | 5 +++++ 3 files changed, 24 insertions(+), 1 deletion(-) diff --git a/include/linux/stackdepot.h b/include/linux/stackdepot.h index e1d05d9adcd1..c6b54199ea26 100644 --- a/include/linux/stackdepot.h +++ b/include/linux/stackdepot.h @@ -120,6 +120,9 @@ depot_stack_handle_t stack_depot_save_action(unsigned long *entries, void *stack_start(struct seq_file *m, loff_t *ppos); void *stack_next(struct seq_file *m, void *v, loff_t *ppos); int stack_print(struct seq_file *m, void *v); + +int page_owner_threshold_get(void *data, u64 *val); +int page_owner_threshold_set(void *data, u64 val); #endif /** diff --git a/lib/stackdepot.c b/lib/stackdepot.c index d0a4e6ac0bc9..2f1a41f0ae4f 100644 --- a/lib/stackdepot.c +++ b/lib/stackdepot.c @@ -502,6 +502,9 @@ static struct stack_record *stack_depot_getstack(depot_stack_handle_t handle) } #ifdef CONFIG_PAGE_OWNER + +static unsigned long page_owner_stack_threshold = 0; + void *stack_start(struct seq_file *m, loff_t *ppos) { unsigned long *table = m->private; @@ -557,7 +560,7 @@ int stack_print(struct seq_file *m, void *v) if (!stack->size || stack->size < 0 || stack->size > PAGE_SIZE || stack->handle.valid != 1 || - refcount_read(&stack->count) < 1) + refcount_read(&stack->count) < page_owner_stack_threshold) return 0; buf = kzalloc(PAGE_SIZE, GFP_KERNEL); @@ -570,6 +573,18 @@ int stack_print(struct seq_file *m, void *v) return 0; } + +int page_owner_threshold_get(void *data, u64 *val) +{ + *val = page_owner_stack_threshold; + return 0; +} + +int page_owner_threshold_set(void *data, u64 val) +{ + page_owner_stack_threshold = val; + return 0; +} #endif unsigned int stack_depot_fetch(depot_stack_handle_t handle, diff --git a/mm/page_owner.c b/mm/page_owner.c index b191ad1d41f9..daec789b0b50 100644 --- a/mm/page_owner.c +++ b/mm/page_owner.c @@ -743,6 +743,9 @@ const struct file_operations page_owner_stack_operations = { .release = seq_release, }; +DEFINE_SIMPLE_ATTRIBUTE(proc_page_owner_threshold, &page_owner_threshold_get, + &page_owner_threshold_set, "%lu"); + static int __init pageowner_init(void) { if (!static_branch_unlikely(&page_owner_inited)) { @@ -755,6 +758,8 @@ static int __init pageowner_init(void) debugfs_create_file("page_owner_stacks", S_IRUSR, NULL, NULL, &page_owner_stack_operations); + debugfs_create_file("page_owner_threshold", 0600, NULL, NULL, + &proc_page_owner_threshold); return 0; }