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 52E4A265621 for ; Tue, 24 Feb 2026 17:47:33 +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=1771955253; cv=none; b=b5c2DSKxOQDtPizpzcBb25SIrzZPEyyF3By/Z2KasLhjO7nQVGuK81H06PUZYJYpognkVY6F/RToGTnuHkbbnN/4eY8yLkO1AUphAwWlEP/TALM0lbeKB3t6O3czV7oiW7cAd14/voO973pcMSUKd6wOpoyCs8S5K1KiwaiTIVM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771955253; c=relaxed/simple; bh=UIuZVxPK9aFZrcXKIBeUE2UvVo54X57AmrkRrYdDIlM=; h=Date:To:From:Subject:Message-Id; b=HU3F7Kc57Kvq56HnCZFwUY+GYRNtqdgJO9ue0sM7bO5g4Zn6YHBIzBG/ej+2s7tWOVTDhsTTl0pMwyvE0nIccE9IJ++/KeSZSCJM1eqpToXW5MhtyUlps0jjH5T3CrghS2R3UYEUgW9FuTcZkvNwsEsr84nENMeaMxeSL4tieq0= 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=TMoxpG+G; 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="TMoxpG+G" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DA905C116D0; Tue, 24 Feb 2026 17:47:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1771955253; bh=UIuZVxPK9aFZrcXKIBeUE2UvVo54X57AmrkRrYdDIlM=; h=Date:To:From:Subject:From; b=TMoxpG+GkKWAgo8qKbzUdgg15HGfGnhom6jZae1Y89b5NZN9IeO6QuTyYDloSooE6 Ma+JP7t/kVziNyIwyTE2bG3hBv/pbxOpmD4RoGvApHxWdZiV1mIhMhRZEk3UWQf1oD /duOQ1Ue/waz8GRG8ICQIlzg1a/7VxaJlm1K7UTM= Date: Tue, 24 Feb 2026 09:47:32 -0800 To: mm-commits@vger.kernel.org,vschneid@redhat.com,vincent.guittot@linaro.org,vbabka@suse.cz,surenb@google.com,rppt@kernel.org,rostedt@goodmis.org,peterz@infradead.org,pasha.tatashin@soleen.com,mjguzik@gmail.com,mingo@redhat.com,mhocko@suse.com,mgorman@suse.de,lorenzo.stoakes@oracle.com,liam.howlett@oracle.com,kees@kernel.org,juri.lelli@redhat.com,dietmar.eggemann@arm.com,david@kernel.org,bsegall@google.com,ankur.a.arora@oracle.com,linusw@kernel.org,akpm@linux-foundation.org From: Andrew Morton Subject: + fork-zero-vmap-stack-using-clear_pages-instead-of-memset.patch added to mm-nonmm-unstable branch Message-Id: <20260224174732.DA905C116D0@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: fork: zero vmap stack using clear_pages() instead of memset() has been added to the -mm mm-nonmm-unstable branch. Its filename is fork-zero-vmap-stack-using-clear_pages-instead-of-memset.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/fork-zero-vmap-stack-using-clear_pages-instead-of-memset.patch This patch will later appear in the mm-nonmm-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 various branches at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there most days ------------------------------------------------------ From: Linus Walleij Subject: fork: zero vmap stack using clear_pages() instead of memset() Date: Tue, 24 Feb 2026 11:26:32 +0100 After the introduction of clear_pages() we exploit the fact that the process vm_area is allocated in contiguous pages to just clear them all in one swift operation. Link: https://lkml.kernel.org/r/20260224-mm-fork-clear-pages-v1-1-184c65a72d49@kernel.org Signed-off-by: Linus Walleij Suggested-by: Mateusz Guzik Link: https://lore.kernel.org/linux-mm/dpnwsp7dl4535rd7qmszanw6u5an2p74uxfex4dh53frpb7pu3@2bnjjavjrepe/ Suggested-by: Pasha Tatashin Link: https://lore.kernel.org/20240311164638.2015063-7-pasha.tatashin@soleen.com Cc: Ankur Arora Cc: Ben Segall Cc: David Hildenbrand Cc: Dietmar Eggemann Cc: Ingo Molnar Cc: Juri Lelli Cc: Kees Cook Cc: Liam Howlett Cc: Lorenzo Stoakes Cc: Mel Gorman Cc: Michal Hocko Cc: Mike Rapoport Cc: Peter Zijlstra Cc: Steven Rostedt Cc: Suren Baghdasaryan Cc: Valentin Schneider Cc: Vincent Guittot Cc: Vlastimil Babka Signed-off-by: Andrew Morton --- kernel/fork.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/kernel/fork.c~fork-zero-vmap-stack-using-clear_pages-instead-of-memset +++ a/kernel/fork.c @@ -350,7 +350,7 @@ static int alloc_thread_stack_node(struc stack = kasan_reset_tag(vm_area->addr); /* Clear stale pointers from reused stack. */ - memset(stack, 0, THREAD_SIZE); + clear_pages(vm_area->addr, vm_area->nr_pages); tsk->stack_vm_area = vm_area; tsk->stack = stack; _ Patches currently in -mm which might be from linusw@kernel.org are fork-zero-vmap-stack-using-clear_pages-instead-of-memset.patch