Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756166AbZFTPdM (ORCPT ); Sat, 20 Jun 2009 11:33:12 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752334AbZFTPc7 (ORCPT ); Sat, 20 Jun 2009 11:32:59 -0400 Received: from mail-px0-f202.google.com ([209.85.216.202]:52565 "EHLO mail-px0-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751593AbZFTPc6 convert rfc822-to-8bit (ORCPT ); Sat, 20 Jun 2009 11:32:58 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=Y4gWjAvLY37d2jZpANdIOZBT35N1AycyE0uJ7DzzIUyx+e7xRztBjgZHz7Q++bcmmI dK8OUNbjsaiLfyMt9LRcAwoJtFPGFYWj82XVbjSovNo5D+dk+saaYyIt6vU05EzT9RYo whtzNu/nU0wgKE6Ex+O51zopEPpJSUMBAGcgQ= MIME-Version: 1.0 In-Reply-To: References: Date: Sat, 20 Jun 2009 21:03:00 +0530 Message-ID: Subject: Re: generic_make_request fucntion for scsi_disk From: Ravish Tayal To: Alan Stern Cc: Kernel development list , linux-fsdevel@vger.kernel.org, SCSI development list , USB list Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 997 Lines: 31 Sorry My mistake. I will take care of it now onwards regards Ravish On Sat, Jun 20, 2009 at 8:26 PM, Alan Stern wrote: > You should use Reply-To-All so that other people reading the mailing > list will be able to follow and contribute to the thread. > > On Sat, 20 Jun 2009, Ravish Tayal wrote: > >> Thanks Alan, >> >> I am actually trying to profile the time taken by each layer to complete the >> disk write opertaion as sys_write to queue_command invokation veries alot. > > Of course it varies. ?The kernel buffers disk writes, shuffles them > around, and then carries them out when it wants to. ?As James has > pointed out, your write(2) system calls don't directly cause any I/O to > take place. > > Alan Stern > > > -- 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/