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 1DF9E468D for ; Mon, 11 Dec 2023 00:55:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="fe1uMwI6" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DC566C433C8; Mon, 11 Dec 2023 00:54:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1702256099; bh=8V9Dzw0fiZkTvyLPwr62n5wdwgYs9RsT0u8S0I7MSgA=; h=Date:To:From:Subject:From; b=fe1uMwI6TJFkgRZZ/SJD3dnQvx22D30uP+X9hEq7kY9xZEmrj+ZjyHNCLzF/dzbqT 6RSA6tPSO1bYI5l6Cak9hs1zwOH0iUMZbq0ou9Rqvl8xGyBkU156rNo4FN/ihuCabJ DvKJDCqfAi89YQQHbx512t7TPuSyYe0fxgLGsE5M= Date: Sun, 10 Dec 2023 16:54:59 -0800 To: mm-commits@vger.kernel.org,vbabka@suse.cz,osalvador@suse.de,glider@google.com,eugenis@google.com,elver@google.com,dvyukov@google.com,andreyknvl@google.com,akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-stable] lib-stackdepot-add-refcount-for-records.patch removed from -mm tree Message-Id: <20231211005459.DC566C433C8@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The quilt patch titled Subject: lib/stackdepot: add refcount for records has been removed from the -mm tree. Its filename was lib-stackdepot-add-refcount-for-records.patch This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Andrey Konovalov Subject: lib/stackdepot: add refcount for records Date: Mon, 20 Nov 2023 18:47:14 +0100 Add a reference counter for how many times a stack records has been added to stack depot. Add a new STACK_DEPOT_FLAG_GET flag to stack_depot_save_flags that instructs the stack depot to increment the refcount. Do not yet decrement the refcount; this is implemented in one of the following patches. Do not yet enable any users to use the flag to avoid overflowing the refcount. This is preparatory patch for implementing the eviction of stack records from the stack depot. Link: https://lkml.kernel.org/r/a3fc14a2359d019d2a008d4ff8b46a665371ffee.1700502145.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov Reviewed-by: Alexander Potapenko Cc: Dmitry Vyukov Cc: Evgenii Stepanov Cc: Marco Elver Cc: Oscar Salvador Cc: Vlastimil Babka Signed-off-by: Andrew Morton --- include/linux/stackdepot.h | 13 ++++++++++--- lib/stackdepot.c | 12 ++++++++++-- 2 files changed, 20 insertions(+), 5 deletions(-) --- a/include/linux/stackdepot.h~lib-stackdepot-add-refcount-for-records +++ a/include/linux/stackdepot.h @@ -39,8 +39,9 @@ typedef u32 depot_flags_t; * to its declaration for more details. */ #define STACK_DEPOT_FLAG_CAN_ALLOC ((depot_flags_t)0x0001) +#define STACK_DEPOT_FLAG_GET ((depot_flags_t)0x0002) -#define STACK_DEPOT_FLAGS_NUM 1 +#define STACK_DEPOT_FLAGS_NUM 2 #define STACK_DEPOT_FLAGS_MASK ((depot_flags_t)((1 << STACK_DEPOT_FLAGS_NUM) - 1)) /* @@ -94,6 +95,9 @@ static inline int stack_depot_early_init * flags of @alloc_flags). Otherwise, stack depot avoids any allocations and * fails if no space is left to store the stack trace. * + * If STACK_DEPOT_FLAG_GET is set in @depot_flags, stack depot will increment + * the refcount on the saved stack trace if it already exists in stack depot. + * * If the provided stack trace comes from the interrupt context, only the part * up to the interrupt entry is saved. * @@ -116,8 +120,11 @@ depot_stack_handle_t stack_depot_save_fl * @nr_entries: Number of frames in the stack * @alloc_flags: Allocation GFP flags * - * Context: Contexts where allocations via alloc_pages() are allowed. - * See stack_depot_save_flags() for more details. + * Does not increment the refcount on the saved stack trace; see + * stack_depot_save_flags() for more details. + * + * Context: Contexts where allocations via alloc_pages() are allowed; + * see stack_depot_save_flags() for more details. * * Return: Handle of the stack trace stored in depot, 0 on failure */ --- a/lib/stackdepot.c~lib-stackdepot-add-refcount-for-records +++ a/lib/stackdepot.c @@ -23,6 +23,7 @@ #include #include #include +#include #include #include #include @@ -60,6 +61,7 @@ struct stack_record { u32 hash; /* Hash in hash table */ u32 size; /* Number of stored frames */ union handle_parts handle; + refcount_t count; unsigned long entries[CONFIG_STACKDEPOT_MAX_FRAMES]; /* Frames */ }; @@ -373,6 +375,7 @@ depot_alloc_stack(unsigned long *entries stack->hash = hash; stack->size = size; /* stack->handle is already filled in by depot_init_pool(). */ + refcount_set(&stack->count, 1); memcpy(stack->entries, entries, flex_array_size(stack, entries, size)); /* @@ -489,6 +492,8 @@ depot_stack_handle_t stack_depot_save_fl /* Fast path: look the stack trace up without full locking. */ found = find_stack(bucket, entries, nr_entries, hash); if (found) { + if (depot_flags & STACK_DEPOT_FLAG_GET) + refcount_inc(&found->count); read_unlock_irqrestore(&pool_rwlock, flags); goto exit; } @@ -528,12 +533,15 @@ depot_stack_handle_t stack_depot_save_fl list_add(&new->list, bucket); found = new; } - } else if (prealloc) { + } else { + if (depot_flags & STACK_DEPOT_FLAG_GET) + refcount_inc(&found->count); /* * Stack depot already contains this stack trace, but let's * keep the preallocated memory for future. */ - depot_keep_new_pool(&prealloc); + if (prealloc) + depot_keep_new_pool(&prealloc); } write_unlock_irqrestore(&pool_rwlock, flags); _ Patches currently in -mm which might be from andreyknvl@google.com are