From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FAKE_REPLY_C,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1, USER_IN_DEF_DKIM_WL autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1C5DFCA9ED3 for ; Mon, 4 Nov 2019 18:27:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E301120869 for ; Mon, 4 Nov 2019 18:27:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=cisco.com header.i=@cisco.com header.b="lZlF6RzD" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729454AbfKDS14 (ORCPT ); Mon, 4 Nov 2019 13:27:56 -0500 Received: from alln-iport-2.cisco.com ([173.37.142.89]:56290 "EHLO alln-iport-2.cisco.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727998AbfKDS14 (ORCPT ); Mon, 4 Nov 2019 13:27:56 -0500 X-Greylist: delayed 425 seconds by postgrey-1.27 at vger.kernel.org; Mon, 04 Nov 2019 13:27:55 EST DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=cisco.com; i=@cisco.com; l=664; q=dns/txt; s=iport; t=1572892075; x=1574101675; h=date:from:to:cc:subject:message-id:mime-version; bh=6eYi3wjyJDjYDvEnI2nl2Du9wgudJvIY7ANx7M1zMok=; b=lZlF6RzDCbzmPeeiW+OAN/NYSEtmr/XTNFZrOiLfEMgPaI3L+WH/V8e0 lXuSPPk/rNUNv129pbjFRKPfZ4dpUKOPxdAMBExbAeiTi07aA69YnXjbS foZfYxG7N5KMD9KxsRPXIW4rgbcYXdIaYIIcJyfS/HAJrziARtTNz86// Y=; X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: =?us-ascii?q?A0C2AAB7asBd/4sNJK1mDgsBAQEBAQE?= =?us-ascii?q?BAQEBAQEBAQEBAREBAQEBAQEBAQEBAYF9giBsVTIqkzaRFYR+hTyBZwkBAQE?= =?us-ascii?q?MAQElCgEBhECEECQ4EwIDCwEBBAEBAQIBBQRthTcMhhI/GyE0BSghARKDI4J?= =?us-ascii?q?3D7FdgieJBoFCBhQOgRSMExiBQD+BEYMSPoQtBINWgiwEjHBEiUqHcI8Egi5?= =?us-ascii?q?thiSOGScMmVktjhWILpEpAgQGBQIVgWkiKoEuMxoIGxWDKBI9ERSMDYUEXCA?= =?us-ascii?q?DMQEBAYwrgj4BAQ?= X-IronPort-AV: E=Sophos;i="5.68,267,1569283200"; d="scan'208";a="365533773" Received: from alln-core-6.cisco.com ([173.36.13.139]) by alln-iport-2.cisco.com with ESMTP/TLS/DHE-RSA-SEED-SHA; 04 Nov 2019 18:20:48 +0000 Received: from zorba ([10.154.200.29]) by alln-core-6.cisco.com (8.15.2/8.15.2) with ESMTPS id xA4IKkpK001680 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Mon, 4 Nov 2019 18:20:47 GMT Date: Mon, 4 Nov 2019 10:20:44 -0800 From: Daniel Walker To: Jens Axboe , Alan Stern , Greg Kroah-Hartman Cc: linux-usb@vger.kernel.org, stable@vger.kernel.org, xe-linux-external@cisco.com Subject: Re: usb-storage: Set virt_boundary_mask to avoid SG overflows Message-ID: <20191104182044.GF18744@zorba> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.9.4 (2018-02-28) X-Auto-Response-Suppress: DR, OOF, AutoReply X-Outbound-SMTP-Client: 10.154.200.29, [10.154.200.29] X-Outbound-Node: alln-core-6.cisco.com Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org Hi, This is a stable defect report. We're tracking v4.9 stable for some of our products (i.e. Cisco Systems, Inc.) We noticed a speed degradation of roughly %30 on writes to a /dev/sdaX device over USB (no file system). We bisected the issue to this commit from Alan Stern. We also found a prior report of speed degradation on NTFS, https://lore.kernel.org/linux-usb/Pine.LNX.4.44L0.1908291030400.1306-100000@iolanthe.rowland.org/T/ We have the patch reverted in our v4.9 tree on top of stable. It seems Alan was planning to remove these lines. If the lines are planned to be removed is there an reason why they haven't been ? Thanks, Daniel