From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759976Ab0JGCXp (ORCPT ); Wed, 6 Oct 2010 22:23:45 -0400 Received: from cantor.suse.de ([195.135.220.2]:49777 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757596Ab0JGCXm (ORCPT ); Wed, 6 Oct 2010 22:23:42 -0400 Date: Wed, 6 Oct 2010 19:19:59 -0700 From: Greg KH To: Sameer Nanda Cc: lenb@kernel.org, stefan.bader@canonical.com, brad.figg@canonical.com, apw@canonical.com, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] ACPI: Read TSC upon resume Message-ID: <20101007021959.GA7300@suse.de> References: <1286406919-6236-1-git-send-email-snanda@chromium.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1286406919-6236-1-git-send-email-snanda@chromium.org> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Oct 06, 2010 at 04:15:19PM -0700, Sameer Nanda wrote: > Read the TSC upon resuming and print it out. This is useful > in helping figure out amount of time spent in the BIOS when > resuming from suspend. > > Change-Id: I1d6a32bd62421becddecd152d561763e5f3e1101 What is this tag for? I don't think it matches anything the kernel community wants, do you? And are you always going to be printing this out? Why do we want to know this every time? > Signed-off-by: Sameer Nanda > --- > drivers/acpi/sleep.c | 4 ++++ > 1 files changed, 4 insertions(+), 0 deletions(-) > > diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c > index c0fed2e..f0588fa 100644 > --- a/drivers/acpi/sleep.c > +++ b/drivers/acpi/sleep.c > @@ -214,6 +214,7 @@ static int acpi_suspend_enter(suspend_state_t pm_state) > acpi_status status = AE_OK; > unsigned long flags = 0; > u32 acpi_state = acpi_target_sleep_state; > + u64 tsc; > > ACPI_FLUSH_CPU_CACHE(); > > @@ -235,6 +236,9 @@ static int acpi_suspend_enter(suspend_state_t pm_state) > > case ACPI_STATE_S3: > do_suspend_lowlevel(); > + rdtscll(tsc); > + printk(KERN_INFO "TSC at resume: %llu\n", > + (unsigned long long)tsc); How long does this take, will it slow down resume? thanks, greg k-h