Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754236Ab3EGPZ0 (ORCPT ); Tue, 7 May 2013 11:25:26 -0400 Received: from mail-ob0-f180.google.com ([209.85.214.180]:42887 "EHLO mail-ob0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756226Ab3EGPZW (ORCPT ); Tue, 7 May 2013 11:25:22 -0400 MIME-Version: 1.0 In-Reply-To: <518097B8.4020402@gmail.com> References: <337833384.57445.1361860509194.JavaMail.mail@webmail08> <569718148.80620.1361906088301.JavaMail.mail@webmail13> <771333906.75854.1367057440028.JavaMail.mail@webmail08> <518097B8.4020402@gmail.com> From: Bjorn Helgaas Date: Tue, 7 May 2013 08:25:01 -0700 Message-ID: Subject: Re: Abysmal HDD/USB write speed after sleep on a UEFI system To: Robert Hancock Cc: "Artem S. Tashkinov" , Alan Stern , Linus Torvalds , "linux-kernel@vger.kernel.org" , "linux-pci@vger.kernel.org" , "Rafael J. Wysocki" , Phillip Susi Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2801 Lines: 79 [+cc Phillip] On Tue, Apr 30, 2013 at 9:19 PM, Robert Hancock wrote: > On 04/29/2013 10:47 PM, Bjorn Helgaas wrote: >> >> On Sat, Apr 27, 2013 at 4:10 AM, Artem S. Tashkinov >> wrote: >>>> >>>> >>>> Did this problem ever get resolved? >>>> >>> >>> Hello, >>> >>> Unfortunately, no. Out of curiosity I've tried booting kernel >>> 3.9-rc8 in EUFI mode but it exhibits the same problem. >>> >>> Right after the boot: >>> >>> [root@localhost ~]# dd if=/dev/zero of=test bs=64M count=3 >>> 3+0 records in >>> 3+0 records out >>> 201326592 bytes (201 MB) copied, 1.08544 s, 185 MB/s >>> >>> After suspend/resume: >>> >>> # dd if=/dev/zero of=test bs=64M count=3 >>> 3+0 records in >>> 3+0 records out >>> 201326592 bytes (201 MB) copied, 66.5392 s, 3.0 MB/s >>> >>> That's for my primary SATA-3 HDD. >>> >>> Forgive me my impudence but I believe debugging the USB stack is >>> tangential to this problem. Something far deeper than USB support >>> breaks, but so far no one has come even with the slightest clue of >>> what that might be. >> >> >> I tend to agree that it sounds like something deeper than USB is >> broken. I admit I'm just grasping at straws because I don't have any >> good ideas yet. >> >> Here are three easy things you can try: >> >> 1) Collect "lspci -vvv -xxxx" output before and after the >> suspend/resume to investigate the XHCI Unsupported Request errors. >> >> 2) Collect the contents of /proc/mtrr before and after the suspend/resume. >> >> 3) After the suspend/resume, try the "setpci" to set the MSI address >> back to the original value to see if it makes a difference (see my Feb >> 12 message). > > > I would suspect that Windows' complaint about the BIOS mucking up the MTRRs > is likely the best hint. Likely Windows is detecting the problem and fixing > it up on resume, thus it only complains about "reduced resume performance". > If the MTRRs are messed up, then quite likely parts of RAM have become > uncacheable, causing performance to get randomly slaughtered in various > ways. > > From looking at the code it's not clear if we are checking/restoring the > MTRR contents after resume. If not, maybe we should be. I agree; the MTRR warning is a good hint. Artem? Phillip, I cc'd you because you have similar hardware and your https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1131468 report is slightly similar. Have you seen anything like this "reduced performance after resume" issue? If so, can you collect /proc/mtrr contents before and after suspending? Bjorn -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/