From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from 013.lax.mailroute.net (013.lax.mailroute.net [199.89.1.16]) (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 255642DF707 for ; Wed, 25 Mar 2026 21:37:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=199.89.1.16 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774474661; cv=none; b=gzVLRwJlChTtW0E8FRG1MBbrVDANPioh9CrDqJJr7tBC2fErtjOFrDyy6RAknT9HyniOrNvMcfSoeT96vbpk7/RRyj3F1EezPneG8j+iEyrDSbvuVHu/f/w2xNuftNW/QsCeGKdKFZdF6D0XeQ9tpFXb1zsS8nt76NycWnFmT3w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774474661; c=relaxed/simple; bh=0SXqQJ400kOLCsvBDoNuA2aRnAhuS/aeFp+Bv9n39IM=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=gw1Q1ytnU+tXKhSWtVmLDrXyvCLGkEBdMHDLT5vLuqZusd6ZF4MU7wYn2d8DDwdbIZk5CIJLD9VfARVJ0F/KYYEuDp/T1rymz+NF1+R/Q/Or7Yk5tJwLWYzsxvOLcjjbD9w9ZhEfr3KsG8j4rfXRRHZWZjWNUW4GWY1gSYJPsOQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=acm.org; spf=pass smtp.mailfrom=acm.org; dkim=pass (2048-bit key) header.d=acm.org header.i=@acm.org header.b=nID8jVcs; arc=none smtp.client-ip=199.89.1.16 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=acm.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=acm.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=acm.org header.i=@acm.org header.b="nID8jVcs" Received: from localhost (localhost [127.0.0.1]) by 013.lax.mailroute.net (Postfix) with ESMTP id 4fh0cY1x34zlfddr; Wed, 25 Mar 2026 21:37:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=acm.org; h= content-transfer-encoding:mime-version:x-mailer:message-id:date :date:subject:subject:from:from:received:received; s=mr01; t= 1774474650; x=1777066651; bh=6rz9Pd3flg9yuvueGLKwPAsje84TQqDFMuN HLlTBEEY=; b=nID8jVcsSBfqy37I5anuiajHme+Nk2iY/aLloXHAurXbv4NuY01 ymwwXBAKoCF9ot7vi7Cd6ojLC2791ohbDeSvxF02Ki4csa1URHSNPzOs6OiuvtSQ Tp+v4W6UZP3OoiqlVcmjja7g/uXj5yWD+T6zGGhDRfZFAJD0o1xDkG/J28da/Uut YzCdq3gCUyf7GKrNnaOuFohS9TBp3klv905kl++UvfSAcHw/qrdN8xjkAY9ZwEIz sqackEBMWmm0TV22LPtYADqdoLwws6Bm2EpEHp0cM7y/ZPORBUdTmt2mkNgo/L5t 1j0W84qQz4sM+4jgu+dimMkCZaVcttTU2Kg== X-Virus-Scanned: by MailRoute Received: from 013.lax.mailroute.net ([127.0.0.1]) by localhost (013.lax [127.0.0.1]) (mroute_mailscanner, port 10029) with LMTP id v2JtKVbkEc1m; Wed, 25 Mar 2026 21:37:30 +0000 (UTC) Received: from bvanassche.mtv.corp.google.com (unknown [104.135.180.219]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: bvanassche@acm.org) by 013.lax.mailroute.net (Postfix) with ESMTPSA id 4fh0cS6099zlfgS0; Wed, 25 Mar 2026 21:37:28 +0000 (UTC) From: Bart Van Assche To: Jens Axboe Cc: linux-block@vger.kernel.org, Christoph Hellwig , Damien Le Moal , Ming Lei , Bart Van Assche Subject: [PATCH v2 0/5] Enable testing small DMA segment sizes Date: Wed, 25 Mar 2026 14:37:10 -0700 Message-ID: <20260325213719.2850619-1-bvanassche@acm.org> X-Mailer: git-send-email 2.53.0.1018.g2bb0e51243-goog Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Hi Jens, About one year ago support was merged for DMA segment sizes smaller than = the virtual memory page size. No blktests exist yet for the new codepaths rel= ated to small segment size support. This patch series makes it possible to tes= t these code paths on a system (e.g. a VM) with 4 KiB pages. The corresponding blktest patch is available here: https://lore.kernel.org/linux-block/20260323200751.1238583-1-bvanassche@a= cm.org/ Please consider this patch series for the next merge window. Changes compared to v1: - Addressed Damien's comment and made the null_blk kernel module paramet= er more clear. - Added three patches to this series: one patch that fixes a source code comment and two patches that reduce the number of users of the BLK_MIN_SEGMENT_SIZE constant. Bart Van Assche (5): block: Fix a source code comment block: Fix the max_user_sectors lower bound block: Remove a DMA segment boundary mask check block: Reduce the minimum value for the maximum DMA segment size null_blk: Support configuring the maximum DMA segment size block/blk-settings.c | 14 ++++---------- block/blk.h | 2 +- drivers/block/null_blk/main.c | 13 +++++++++++++ drivers/block/null_blk/null_blk.h | 1 + 4 files changed, 19 insertions(+), 11 deletions(-)