From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756451AbZFWIR0 (ORCPT ); Tue, 23 Jun 2009 04:17:26 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751776AbZFWIRM (ORCPT ); Tue, 23 Jun 2009 04:17:12 -0400 Received: from mail-yx0-f196.google.com ([209.85.210.196]:48369 "EHLO mail-yx0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751729AbZFWIRK (ORCPT ); Tue, 23 Jun 2009 04:17:10 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:date:message-id:subject:from:to:content-type; b=lIm4/N2OWidq+ZXa5iatg0OFceYtwMiE3g4Odmu1do57evDUnrW8KDQLxVAhUonLYm xUkO9SqwQXvLhXd9bnKQiVKKehj3AenoSNHiIAccqDGHQS9bpe16+OJy/8bei0ZZYpIk aHw+HZMP4yrvsPMWZMbR8FHSu62o+974m6DKg= MIME-Version: 1.0 Date: Tue, 23 Jun 2009 16:17:06 +0800 Message-ID: Subject: mm: dirty page problem From: xue yong To: linux-kernel@vger.kernel.org Content-Type: multipart/mixed; boundary=0016368e1b8bcad073046cff9d03 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --0016368e1b8bcad073046cff9d03 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit I wrote a test program. It mmap a file and do some write, so some pages become dirty. and then I do "cat /proc/meminfo", so I get dirty pages that I have written. this happened in my home computer with debian, self compiled kernel 2.6.18-5 installed. but in my company, on the servers (suse kernel 2.6.16.54), after the test program have written the data, there was no change in dirty pages column of "cat /proc/meminfo" 's output. after I killed the test program, the dirty pages changed immediately. I dont know why such different behavior, can you help me? becauce we want a program mmap some files, and after the files' contents were changed, the OS can write out these dirty data back to disk periodly. Best regards! --0016368e1b8bcad073046cff9d03 Content-Type: application/octet-stream; name="mmaptest.c" Content-Disposition: attachment; filename="mmaptest.c" Content-Transfer-Encoding: base64 X-Attachment-Id: f_fwace4j40 I2luY2x1ZGUgPHN0ZGxpYi5oPg0KI2luY2x1ZGUgPHN0ZGlvLmg+DQojaW5jbHVkZSA8c3lzL3R5 cGVzLmg+DQojaW5jbHVkZSA8c3lzL21tYW4uaD4NCiNpbmNsdWRlIDxzeXMvdGltZS5oPg0KI2lu Y2x1ZGUgPHRpbWUuaD4NCiNpbmNsdWRlIDxzeXMvc3RhdC5oPg0KI2luY2x1ZGUgPGZjbnRsLmg+ DQppbnQgbWFpbigpDQp7DQogICAgaW50IGZkOw0KICAgIGNoYXIgKnBtOw0KICAgIHN0cnVjdCBz dGF0IHN0Ow0KICAgIHBpZF90IHA7DQovLyAgICBwID0gZm9yaygpOw0KICAgIGZkID0gb3Blbigi L2hvbWUvaWNlL21tYXAuZGF0IiwgT19SRFdSKTsNCiAgICBpZiggZmQgPCAwICl7DQogICAgICAg IHBlcnJvcigib3BlbiBtbWFwLmRhdCBlcnJvciIpOw0KICAgICAgICBleGl0KDEpOw0KICAgIH0N CiAgICBpZiAoIGZzdGF0KGZkLCAmc3QpICE9IDAgKXsNCiAgICAgICAgcGVycm9yKCJzdGF0IGVy cm9yIik7DQogICAgICAgIGV4aXQoMSk7DQogICAgfQ0KICAgIHBtID0gKGNoYXIqKSBtbWFwKCBO VUxMLCBzdC5zdF9zaXplLCBQUk9UX1dSSVRFIHwgUFJPVF9SRUFEICwgTUFQX1NIQVJFRCAsIGZk LCAwKTsNCi8vICAgIHBtID0gKGNoYXIqKSBtbWFwKCBOVUxMLCBzdC5zdF9zaXplLCAgUFJPVF9S RUFEICwgTUFQX1NIQVJFRCAsIGZkLCAwKTsNCiAgICBpZiAoIHBtIDwgMCB8fCBwbSA9PSBNQVBf RkFJTEVEICl7DQogICAgICAgIHBlcnJvcigibW1hcCBmYWlsZWQiKTsNCiAgICAgICAgZXhpdCgx KTsNCiAgICB9DQogICAgDQogICAgc3RydWN0IHRpbWV2YWwgdEJlZ2luLCB0RW5kOw0KICAgIGJ6 ZXJvKCAmdEJlZ2luLCBzaXplb2YodEJlZ2luKSApOw0KICAgIGJ6ZXJvKCAmdEVuZCwgc2l6ZW9m KHRFbmQpICk7DQoNCiAgICBnZXR0aW1lb2ZkYXkoICZ0QmVnaW4sIE5VTEwpOw0KICAgIGludCBp Ow0KICAgIGNoYXIgYnVmZmVyWzQwOTZdOw0KLy8gICAgcmVhZCggZmQsIGJ1ZmZlciwgNDA5Nik7 DQogICAgd2hpbGUoMSl7DQogICAgZm9yKCBpID0gMDsgaSA8IDEwMjQqMTAwOyArK2kgKQ0KICAg IHsNCiAgICAgICAgbWVtY3B5KCBwbSArIDQwOTYqaSxidWZmZXIsIDQwOTYgKTsNCi8vICAgICAg ICBwd3JpdGUoIGZkLCBidWZmZXIsIDQwOTYsIGkgKiA0MDk2ICk7DQoNCiAgICB9DQogICAgc2xl ZXAoMzAwKTsNCiAgICB9DQovLyAgICBtbG9ja2FsbChNQ0xfQ1VSUkVOVCk7DQovLw0KICAgIGdl dHRpbWVvZmRheSggJnRFbmQsIE5VTEwpOw0KICAgIGludCBsaVRpbWVEaWZmID0gKCh0RW5kLnR2 X3NlYyAtIHRCZWdpbi50dl9zZWMpICogMTAwMDAwMCArIHRFbmQudHZfdXNlYyAtIHRCZWdpbi50 dl91c2VjICkgLyAxMDAwOw0KICAgIHByaW50ZigiJWQgbXNcbiIsIGxpVGltZURpZmYgKTsNCiAg ICBwcmludGYoIm1zeW5jXG4iKTsNCiAgICBtc3luYyggcG0sIHN0LnN0X3NpemUsIE1TX1NZTkMg KTsNCiAgICBtdW5tYXAoIHBtLCBzdC5zdF9zaXplICk7DQovLyAgICBzbGVlcCg2MDApOw0KfQ== --0016368e1b8bcad073046cff9d03--