From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from zps19.corp.google.com (zps19.corp.google.com [172.25.146.19]) by smtp-out.google.com with ESMTP id m3TDAcUl032550 for ; Tue, 29 Apr 2008 14:10:39 +0100 Received: from fg-out-1718.google.com (fge22.prod.google.com [10.86.5.22]) by zps19.corp.google.com with ESMTP id m3TDAawK019436 for ; Tue, 29 Apr 2008 06:10:37 -0700 Received: by fg-out-1718.google.com with SMTP id 22so4673015fge.18 for ; Tue, 29 Apr 2008 06:10:36 -0700 (PDT) Message-ID: Date: Tue, 29 Apr 2008 09:10:36 -0400 From: "Ross Biro" Subject: Page Faults slower in 2.6.25-rc9 than 2.6.23 MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline Sender: owner-linux-mm@kvack.org Return-Path: To: linux-mm@kvack.org, lkml List-ID: I don't know if this has been noticed before. I was benchmarking my page table relocation code and I noticed that on 2.6.25-rc9 page faults take 10% more time than on 2.6.22. This is using lmbench running on an intel x86_64 system. The good news is that the page table relocation code now only adds a 1.6% slow down to page faults. Ross 2.6.25-rc9: File & VM system latencies in microseconds - smaller is better ------------------------------------------------------------------------------- Host OS 0K File 10K File Mmap Prot Page 100fd Create Delete Create Delete Latency Fault Fault selct --------- ------------- ------ ------ ------ ------ ------- ----- ------- ----- ipnn2 Linux 2.6.25- 13.9 7.6111 103.4 9.7453 926.0 0.711 2.14250 2.552 ipnn2 Linux 2.6.25- 13.7 7.6243 310.7 9.6574 932.0 0.750 2.15970 2.555 ipnn2 Linux 2.6.25- 13.9 7.6831 192.5 10.0 927.0 0.760 2.21310 2.553 ipnn2 Linux 2.6.25- 13.9 7.5739 98.4 9.5330 927.0 0.703 2.17610 2.554 ipnn2 Linux 2.6.25- 14.6 7.6429 39.1 10.8 935.0 0.763 2.17250 2.552 ipnn2 Linux 2.6.25- 14.1 7.8777 129.8 9.9375 930.0 0.782 2.26460 2.559 ipnn2 Linux 2.6.25- 14.8 7.9639 623.8 8.2042 927.0 0.773 2.21510 2.557 ipnn2 Linux 2.6.25- 14.4 7.5842 622.3 8.3272 920.0 0.745 2.22210 2.558 ipnn2 Linux 2.6.25- 14.2 7.6339 45.7 10.2 935.0 0.675 2.23860 2.554 ipnn2 Linux 2.6.25- 14.1 7.7175 263.7 10.1 929.0 0.762 2.22350 2.556 ipnn2 Linux 2.6.25- 13.9 8.1230 378.2 9.4343 975.0 0.752 2.25920 2.554 2.6.23: File & VM system latencies in microseconds - smaller is better ------------------------------------------------------------------------------- Host OS 0K File 10K File Mmap Prot Page 100fd Create Delete Create Delete Latency Fault Fault selct --------- ------------- ------ ------ ------ ------ ------- ----- ------- ----- ipnn2 Linux 2.6.23- 218.0 0.912 1.94010 2.626 ipnn2 Linux 2.6.23- 219.0 1.095 1.96400 2.597 ipnn2 Linux 2.6.23- 219.0 0.774 1.96640 2.603 ipnn2 Linux 2.6.23- 221.0 0.946 1.99950 2.601 ipnn2 Linux 2.6.23- 219.0 0.902 1.99160 2.733 ipnn2 Linux 2.6.23- 217.0 0.904 2.04790 2.601 ipnn2 Linux 2.6.23- 225.0 0.893 1.99620 2.600 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org