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 68412286D6E for ; Tue, 10 Jun 2025 09:22:04 +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=1749547324; cv=none; b=t3oH9vzO3DPgn0q58AaW95Nh6cF+abD605sUWJvIgYD7oE8ocUXmAut625713dsYC1462dsRx8LS5429HIzFwCoqtTjJ2qrjLs5uUbhk4jJ5VlHS34+ytPYmz1F9LBgTBX3UTfGhmlKyxSQabnaYuGjO5smMw7yp3KAKVisu6Yw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749547324; c=relaxed/simple; bh=YGXBP9lwMZfji91RKvnUA24jkXgM6whNm6o4hq7TUoM=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=GkHpiVZtK/0FNoIEh8m7un0pObFLeJnVCVzjcTVARL+12eVYor+QO/3ptaj1HAkfAx6Z1OdVgXR5/Izyt/vZ2RHHssvw+eJUjIdyiZTdViJaaFGfMJeVoYUadTWvMn4GWCXz6poM1IEgGNXpy3tTPs/nOTw0ubkHMfcJN6sU8KA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=svACTFx0; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="svACTFx0" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E9C35C4CEEF; Tue, 10 Jun 2025 09:22:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1749547323; bh=YGXBP9lwMZfji91RKvnUA24jkXgM6whNm6o4hq7TUoM=; h=From:To:Cc:Subject:Date:From; b=svACTFx09ibq9oXJmJ5KtYYuSNq+csVKSuSUFl0u+XBinwGs078V0humsqDKKCwEX FjWoMA/LrI51XhkQ9JNaocFw3mfRzWRJAZeJy32EWwV4D1vcQ8pV1J92cCq5o5z8ta XFIOJuib7imHaaxDV6RjcHX1yYVfePRuf0M1PJueMiFN3oiJD8dWJ4rBb/W5JEAmls KpkMp2vWAY43Yn4RIRmBlGlaDfLwRFpD6b+FJQv8KCNGIoQYqI8up0qne7yaEiZBVC m5KCHidQ7h07//TeBMRQYOTL/3Nr7bHAfAf91sXjVaJkDu8679kn6gOqV8fKrWJRLu zHjDRTJY05IVA== From: Arnd Bergmann To: Andrew Morton , =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= Cc: Arnd Bergmann , David Hildenbrand , Alistair Popple , Jason Gunthorpe , Thorsten Blum , Jeff Johnson , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH] lib/test_hmm: reduce stack usage Date: Tue, 10 Jun 2025 11:21:50 +0200 Message-Id: <20250610092159.2639515-1-arnd@kernel.org> X-Mailer: git-send-email 2.39.5 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Arnd Bergmann The various test ioctl handlers use arrays of 64 integers that add up to 1KiB of stack data, which in turn leads to exceeding the warning limit in some configurations: lib/test_hmm.c:935:12: error: stack frame size (1408) exceeds limit (1280) in 'dmirror_migrate_to_device' [-Werror,-Wframe-larger-than] Use half the size for these arrays, in order to stay under the warning limits. The code can already deal with arbitrary lengths, but this may be a little less efficient. Signed-off-by: Arnd Bergmann --- lib/test_hmm.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/lib/test_hmm.c b/lib/test_hmm.c index 5b144bc5c4ec..761725bc713c 100644 --- a/lib/test_hmm.c +++ b/lib/test_hmm.c @@ -330,7 +330,7 @@ static int dmirror_fault(struct dmirror *dmirror, unsigned long start, { struct mm_struct *mm = dmirror->notifier.mm; unsigned long addr; - unsigned long pfns[64]; + unsigned long pfns[32]; struct hmm_range range = { .notifier = &dmirror->notifier, .hmm_pfns = pfns, @@ -879,8 +879,8 @@ static int dmirror_migrate_to_system(struct dmirror *dmirror, unsigned long size = cmd->npages << PAGE_SHIFT; struct mm_struct *mm = dmirror->notifier.mm; struct vm_area_struct *vma; - unsigned long src_pfns[64] = { 0 }; - unsigned long dst_pfns[64] = { 0 }; + unsigned long src_pfns[32] = { 0 }; + unsigned long dst_pfns[32] = { 0 }; struct migrate_vma args = { 0 }; unsigned long next; int ret; @@ -939,8 +939,8 @@ static int dmirror_migrate_to_device(struct dmirror *dmirror, unsigned long size = cmd->npages << PAGE_SHIFT; struct mm_struct *mm = dmirror->notifier.mm; struct vm_area_struct *vma; - unsigned long src_pfns[64] = { 0 }; - unsigned long dst_pfns[64] = { 0 }; + unsigned long src_pfns[32] = { 0 }; + unsigned long dst_pfns[32] = { 0 }; struct dmirror_bounce bounce; struct migrate_vma args = { 0 }; unsigned long next; @@ -1144,8 +1144,8 @@ static int dmirror_snapshot(struct dmirror *dmirror, unsigned long size = cmd->npages << PAGE_SHIFT; unsigned long addr; unsigned long next; - unsigned long pfns[64]; - unsigned char perm[64]; + unsigned long pfns[32]; + unsigned char perm[32]; char __user *uptr; struct hmm_range range = { .hmm_pfns = pfns, -- 2.39.5