From owner-freebsd-hackers Fri Oct 12 14:53:57 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from navgwout.symantec.com (navgwout.symantec.com [198.6.49.12]) by hub.freebsd.org (Postfix) with ESMTP id 3C60837B408 for ; Fri, 12 Oct 2001 14:53:53 -0700 (PDT) Received: from navgwout.symantec.com (navgwout [198.6.49.12]) by navgwout.symantec.com (8.9.3+Sun/8.9.3) with SMTP id OAA13037 for ; Fri, 12 Oct 2001 14:53:49 -0700 (PDT) Received: from mailer.symantec.com ([198.6.49.176]) by navgwout.symantec.com (NAVGW 2.5.1.13) with SMTP id M2001101214534812142 for ; Fri, 12 Oct 2001 14:53:48 -0700 Received: from uscu-smtp02.symantec.com (uscu-smtp02.symantec.com [155.64.74.114]) by mailer.symantec.com (8.9.3+Sun/8.9.3) with ESMTP id OAA18687 for ; Fri, 12 Oct 2001 14:53:48 -0700 (PDT) Subject: Severe I/O Problems To: freebsd-hackers@freebsd.org X-Mailer: Lotus Notes Release 5.0.8 June 18, 2001 Message-ID: From: "Jay Rossiter" Date: Fri, 12 Oct 2001 14:51:10 -0700 X-MIMETrack: Serialize by Router on USCU-SMTP02/SYMSMTP(Release 5.0.8 |June 18, 2001) at 10/12/2001 02:46:37 PM MIME-Version: 1.0 Content-type: text/plain; charset=us-ascii Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG Someone on -questions recommended that I forward this over here for you guys to look at. (I'm not subbed to this list) There appear to be a lot of changes that went into the filesystem and I/O code between 4.3 and 4.4. A little over a week ago I upgraded my 4.3 box to 4.4-STABLE and immediately I started having I/O slowdown. I do development and QA on a program that is very I/O bound, but the changes between 4.3 and 4.4 aren't small enough that I can ignore them. A few statistics: BSD, P4 1.4GHz, ATA100 drives - Normal test run on 4.3 was taking ~3 hours. - Normal test run on 4.4 is taking 15-16 hours. P3-800, ATA66 drives, SuSE Linux 7.1: - Normal test run takes ~4.5 hours. UltraSparc 10, Solaris 8, ATA66 drives: - Normal test run takes ~6 hours. As you can see, this jump was just phenomenal. I can run these tests on a custom 'ramdrive' and the test run takes 1.5 hours on BSD. ~4 on Solaris, ~2.5 on Linux. Even the RS/6000 I test AIX 4.3 with doesn't take this long, though I don't have statistics for it. It appears that the app gets stuck switching between the getblk and biowr states in top and ps, and very rarely does it take more than 5% of the CPU. On all other OS's, and even on 4.3, this app was pegging the CPU while it did its work. Basically.. this all comes down to "What the hell is going on here?!" and "Are there plans to fix it and did anyone even know there was a problem?" --- Jay Rossiter 503-614-7917 QA Engineer, Test Lead Symantec Corp. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message