From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out30-119.freemail.mail.aliyun.com (out30-119.freemail.mail.aliyun.com [115.124.30.119]) (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 5E4703C4571 for ; Tue, 24 Mar 2026 08:11:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.119 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774339876; cv=none; b=AUAS/WysEgovmqNNrDL/2hQdZzmUuobu1CXIv1nOyOGwxBeBnYrjea02uNTv3DqLEpxfjOy4sylARUYguxWz0usZc6HHfBMrqzdPuS3UdD4Ntg9ObyWaeHFWjbtCJPwfOdMo7ANbkcD1NOvPcpPH60yVshWdiYsvD6RGJ3mzmJM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774339876; c=relaxed/simple; bh=cnHoXQdm8lmdaUINvaGBr2b5EuN+kOsdEclENd+eA3w=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=uk+CzyzhpJcEH1+VVPw0d9qERHnI9QEn4WQdrXs3vHjUARluAHt6KKm46KmmdQr3t8ch28bg9YQ8o5OUtWp1Y4DgC/wf085zmD0g1AN9R2d2r/dd4rXrFukvGlDIpZ6zWaveKigyNIr7VD51tyCHhHNoU7ehtP4e8cO52Wu9qus= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b=hFKj7gPb; arc=none smtp.client-ip=115.124.30.119 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b="hFKj7gPb" DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1774339857; h=From:To:Subject:Date:Message-ID:MIME-Version:Content-Type; bh=ovdqLfrLfNLqQkHe/B9nBLf4SoIZKFL5iWuK+Ra6vtg=; b=hFKj7gPblgHPrpqJpE0BlHR/AfNx5phOikK0dhtwWGjuvn+srI4HdMpBUpy3vbqbC1uXX6Be0HHAb9wNo0RWxMH9ZlxTGUetpkhXVeFjJzw1/d+EDpJt4W5IO6dIfSFoSC4hK6QQ/z+q/jbFqKTLIo1bloTtyMG0VxuZtoWIYaY= X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R201e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=maildocker-contentspam033032089153;MF=ying.huang@linux.alibaba.com;NM=1;PH=DS;RN=39;SR=0;TI=SMTPD_---0X.dvi7y_1774339843; Received: from DESKTOP-5N7EMDA(mailfrom:ying.huang@linux.alibaba.com fp:SMTPD_---0X.dvi7y_1774339843 cluster:ay36) by smtp.aliyun-inc.com; Tue, 24 Mar 2026 16:10:53 +0800 From: "Huang, Ying" To: Shivank Garg Cc: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: Re: [RFC PATCH v4 5/6] drivers/migrate_offload: add DMA batch copy driver (dcbm) In-Reply-To: <20260309120725.308854-14-shivankg@amd.com> (Shivank Garg's message of "Mon, 9 Mar 2026 12:07:31 +0000") References: <20260309120725.308854-3-shivankg@amd.com> <20260309120725.308854-14-shivankg@amd.com> Date: Tue, 24 Mar 2026 16:10:43 +0800 Message-ID: <874im51wcc.fsf@DESKTOP-5N7EMDA> User-Agent: Gnus/5.13 (Gnus v5.13) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=ascii Hi, Shivank, Shivank Garg writes: > Simple DMAEngine based driver that uses memcpy channels to batch-copy > folios during page migration. Primarily for testing the copy offload > infrastructure. > > When DMA fails the callback returns an error and the migration path > falls back to per-folio CPU copy. > > Sysfs interface under /sys/kernel/dcbm/: > offloading - enable/disable DMA offload > nr_dma_chan - max number of DMA channels to use > folios_migrated - folios copied via DMA > folios_failures - fallback count How about placing the sysfs interface under /sys/module/dcbm/? We will have multiple migrator implementations in the future, so dcbm behaves more like a driver, right? --- Best Regards, Huang, Ying [snip]