From patchwork Tue Sep 22 14:15:46 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: SeongJae Park X-Patchwork-Id: 11792657 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 7C3C0112C for ; Tue, 22 Sep 2020 14:19:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 586C92076E for ; Tue, 22 Sep 2020 14:19:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b="ZMLFvINU" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726494AbgIVOTT (ORCPT ); Tue, 22 Sep 2020 10:19:19 -0400 Received: from smtp-fw-9101.amazon.com ([207.171.184.25]:29546 "EHLO smtp-fw-9101.amazon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726631AbgIVOTT (ORCPT ); Tue, 22 Sep 2020 10:19:19 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1600784358; x=1632320358; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=OBQsZyJBuiCetLUlZLSO8CKNXhhvxT++kw73YrVj7g0=; b=ZMLFvINUchbBnXVz1uNieZXbyHKlYC4jFKfaLbBq8yRvlC0vBvgGgSR/ ZKwHvblAfKCDb89UvIq4ViU4iFL9SEF1S6BMQiMqs3yW90rnZMXNWFR5H Xhp/jL6IPUHYM7OUSLnn8Ft3+Ex/ieN+v7AjD7F00qPbvTmpLwL0nQ7pQ k=; X-IronPort-AV: E=Sophos;i="5.77,291,1596499200"; d="scan'208";a="70117511" Received: from sea32-co-svc-lb4-vlan3.sea.corp.amazon.com (HELO email-inbound-relay-2b-c300ac87.us-west-2.amazon.com) ([10.47.23.38]) by smtp-border-fw-out-9101.sea19.amazon.com with ESMTP; 22 Sep 2020 14:16:13 +0000 Received: from EX13D31EUA004.ant.amazon.com (pdx4-ws-svc-p6-lb7-vlan2.pdx.amazon.com [10.170.41.162]) by email-inbound-relay-2b-c300ac87.us-west-2.amazon.com (Postfix) with ESMTPS id DB8BCA215B; Tue, 22 Sep 2020 14:16:12 +0000 (UTC) Received: from u3f2cd687b01c55.ant.amazon.com (10.43.160.137) by EX13D31EUA004.ant.amazon.com (10.43.165.161) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Tue, 22 Sep 2020 14:16:06 +0000 From: SeongJae Park To: , , CC: SeongJae Park , , , , , , , , Subject: [PATCH v3 0/3] xen-blk(back|front): Let users disable persistent grants Date: Tue, 22 Sep 2020 16:15:46 +0200 Message-ID: <20200922141549.26154-1-sjpark@amazon.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 X-Originating-IP: [10.43.160.137] X-ClientProxiedBy: EX13D12UWC001.ant.amazon.com (10.43.162.78) To EX13D31EUA004.ant.amazon.com (10.43.165.161) Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org From: SeongJae Park Persistent grants feature provides high scalability. On some small systems, however, it could incur data copy overheads[1] and thus it is required to be disabled. But, there is no option to disable it. For the reason, this commit adds module parameters for disabling of the feature. [1] https://wiki.xen.org/wiki/Xen_4.3_Block_Protocol_Scalability Baseline and Complete Git Trees =============================== The patches are based on the v5.9-rc6. You can also clone the complete git tree: $ git clone git://github.com/sjp38/linux -b pgrants_disable_v3 The web is also available: https://github.com/sjp38/linux/tree/pgrants_disable_v3 Patch History ============= Changes from v2 (https://lore.kernel.org/linux-block/20200922105209.5284-1-sjpark@amazon.com/) - Avoid race conditions (Roger Pau Monné) Changes from v1 (https://lore.kernel.org/linux-block/20200922070125.27251-1-sjpark@amazon.com/) - use 'bool' parameter type (Jürgen Groß) - Let blkfront can also disable the feature from its side (Roger Pau Monné) - Avoid unnecessary xenbus_printf (Roger Pau Monné) - Update frontend parameter doc SeongJae Park (3): xen-blkback: add a parameter for disabling of persistent grants xen-blkfront: add a parameter for disabling of persistent grants xen-blkfront: Apply changed parameter name to the document .../ABI/testing/sysfs-driver-xen-blkback | 9 ++++++++ .../ABI/testing/sysfs-driver-xen-blkfront | 11 +++++++++- drivers/block/xen-blkback/xenbus.c | 22 ++++++++++++++----- drivers/block/xen-blkfront.c | 20 ++++++++++++----- 4 files changed, 50 insertions(+), 12 deletions(-) Acked-by: Roger Pau Monné