From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 07BEF13B7A3 for ; Wed, 14 Feb 2024 18:32:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707935555; cv=none; b=qRptYRmGyCUJ3VJY0GGHJ2ZRG6kfiwzUKl1HIEGvA5OBaDTTsKFQ0RBCC4hoh5lLpA+CRjjIgwmRXD3WCHusfu1j+p8v5v10db3qOgRo4xz0XT1BAOsMUpE4x/nSE+L4I40AWci1ny4+WR128cUSKZsmVTjkVlxi9ByQ3q0jSYA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707935555; c=relaxed/simple; bh=RNhlx/yefEpFh0sIVNj/2EXHh8um9A0vMBguH9mJzCM=; h=Date:To:From:Subject:Message-Id; b=NxmT44JlUvOlygmZKqnqtYY4jFeB8qKwrIfK6zmEGdNbPH8egdXdicQbAEqW+1QrOOazaZ9n89bb6eIXOakhn+6fCB6HdznLHIk4+mfiBA91v/ELYRNyz80dz+xPB+RTACMSAayB5UUWVbV6nGFI4xgI953RET4hA+S6eXr5jHo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=WtrOWIfo; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="WtrOWIfo" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 56CD1C433F1; Wed, 14 Feb 2024 18:32:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1707935554; bh=RNhlx/yefEpFh0sIVNj/2EXHh8um9A0vMBguH9mJzCM=; h=Date:To:From:Subject:From; b=WtrOWIfoaXSuG/M+0Txf01cxkSO8Y518pVGfFaDWE8PNqe8GS4r+K0K5mFiuT2S1V cYg/R7two4wsecHi+i8qQPCucCKjQp3qAldanazFylHgsWIaDlYkIWaX2XlPslJ3B/ VTKRJbZWQK/yCv/o+/aQIbHRw71MX4xEHtwctwJI= Date: Wed, 14 Feb 2024 10:32:33 -0800 To: mm-commits@vger.kernel.org,vbabka@suse.cz,mhocko@suse.com,glider@google.com,elver@google.com,andreyknvl@gmail.com,osalvador@suse.de,akpm@linux-foundation.org From: Andrew Morton Subject: + mmpage_owner-maintain-own-list-of-stack_records-structs.patch added to mm-unstable branch Message-Id: <20240214183234.56CD1C433F1@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: mm,page_owner: maintain own list of stack_records structs has been added to the -mm mm-unstable branch. Its filename is mmpage_owner-maintain-own-list-of-stack_records-structs.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mmpage_owner-maintain-own-list-of-stack_records-structs.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Oscar Salvador Subject: mm,page_owner: maintain own list of stack_records structs Date: Wed, 14 Feb 2024 18:01:53 +0100 page_owner needs to increment a stack_record refcount when a new allocation occurs, and decrement it on a free operation. In order to do that, we need to have a way to get a stack_record from a handle. Implement __stack_depot_get_stack_record() which just does that, and make it public so page_owner can use it. Also, traversing all stackdepot buckets comes with its own complexity, plus we would have to implement a way to mark only those stack_records that were originated from page_owner, as those are the ones we are interested in. For that reason, page_owner maintains its own list of stack_records, because traversing that list is faster than traversing all buckets while keeping at the same time a low complexity. For now, add to stack_list only the stack_records of dummy_handle and failure_handle, and set their refcount of 1. Further patches will add code to increment or decrement stack_records count on allocation and free operation. Link: https://lkml.kernel.org/r/20240214170157.17530-4-osalvador@suse.de Signed-off-by: Oscar Salvador Cc: Alexander Potapenko Cc: Andrey Konovalov Cc: Marco Elver Cc: Michal Hocko Cc: Vlastimil Babka Signed-off-by: Andrew Morton --- include/linux/stackdepot.h | 11 +++++++++++ lib/stackdepot.c | 8 ++++++++ mm/page_owner.c | 15 +++++++++++++++ 3 files changed, 34 insertions(+) --- a/include/linux/stackdepot.h~mmpage_owner-maintain-own-list-of-stack_records-structs +++ a/include/linux/stackdepot.h @@ -179,6 +179,17 @@ depot_stack_handle_t stack_depot_save(un unsigned int nr_entries, gfp_t gfp_flags); /** + * __stack_depot_get_stack_record - Get a pointer to a stack_record struct + * + * @handle: Stack depot handle + * + * This function is only for internal purposes. + * + * Return: Returns a pointer to a stack_record struct + */ +struct stack_record *__stack_depot_get_stack_record(depot_stack_handle_t handle); + +/** * stack_depot_fetch - Fetch a stack trace from stack depot * * @handle: Stack depot handle returned from stack_depot_save() --- a/lib/stackdepot.c~mmpage_owner-maintain-own-list-of-stack_records-structs +++ a/lib/stackdepot.c @@ -687,6 +687,14 @@ depot_stack_handle_t stack_depot_save(un } EXPORT_SYMBOL_GPL(stack_depot_save); +struct stack_record *__stack_depot_get_stack_record(depot_stack_handle_t handle) +{ + if (!handle) + return NULL; + + return depot_fetch_stack(handle); +} + unsigned int stack_depot_fetch(depot_stack_handle_t handle, unsigned long **entries) { --- a/mm/page_owner.c~mmpage_owner-maintain-own-list-of-stack_records-structs +++ a/mm/page_owner.c @@ -36,6 +36,14 @@ struct page_owner { pid_t free_tgid; }; +struct stack { + struct stack_record *stack_record; + struct stack *next; +}; +static struct stack dummy_stack; +static struct stack failure_stack; +static struct stack *stack_list; + static bool page_owner_enabled __initdata; DEFINE_STATIC_KEY_FALSE(page_owner_inited); @@ -95,6 +103,13 @@ static __init void init_page_owner(void) register_early_stack(); static_branch_enable(&page_owner_inited); init_early_allocated_pages(); + /* Initialize dummy and failure stacks and link them to stack_list */ + dummy_stack.stack_record = __stack_depot_get_stack_record(dummy_handle); + failure_stack.stack_record = __stack_depot_get_stack_record(failure_handle); + refcount_set(&dummy_stack.stack_record->count, 1); + refcount_set(&failure_stack.stack_record->count, 1); + dummy_stack.next = &failure_stack; + stack_list = &dummy_stack; } struct page_ext_operations page_owner_ops = { _ Patches currently in -mm which might be from osalvador@suse.de are lib-stackdepot-fix-first-entry-having-a-0-handle.patch lib-stackdepot-move-stack_record-struct-definition-into-the-header.patch mmpage_owner-maintain-own-list-of-stack_records-structs.patch mmpage_owner-implement-the-tracking-of-the-stacks-count.patch mmpage_owner-display-all-stacks-and-their-count.patch mmpage_owner-filter-out-stacks-by-a-threshold.patch mmpage_owner-update-documentation-regarding-page_owner_stacks.patch