From patchwork Wed Aug 25 21:43:11 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Glauber Costa X-Patchwork-Id: 132921 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter.kernel.org (8.14.4/8.14.3) with ESMTP id o7PLxKFd027431 for ; Wed, 25 Aug 2010 21:59:20 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753274Ab0HYV7R (ORCPT ); Wed, 25 Aug 2010 17:59:17 -0400 Received: from mx1.redhat.com ([209.132.183.28]:21270 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753251Ab0HYV7Q (ORCPT ); Wed, 25 Aug 2010 17:59:16 -0400 Received: from int-mx03.intmail.prod.int.phx2.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.16]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id o7PLxFHr024924 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Wed, 25 Aug 2010 17:59:16 -0400 Received: from localhost.localdomain (virtlab1.virt.bos.redhat.com [10.16.72.21]) by int-mx03.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id o7PLxDaU022101; Wed, 25 Aug 2010 17:59:14 -0400 From: Glauber Costa To: kvm@vger.kernel.org Cc: avi@redhat.com, zamsden@redhat.com, mtosatti@redhat.com, riel@redhat.com Subject: [RFC 1/7] Implement getnsboottime kernel API Date: Wed, 25 Aug 2010 17:43:11 -0400 Message-Id: <1282772597-4183-2-git-send-email-glommer@redhat.com> In-Reply-To: <1282772597-4183-1-git-send-email-glommer@redhat.com> References: <1282772597-4183-1-git-send-email-glommer@redhat.com> X-Scanned-By: MIMEDefang 2.67 on 10.5.11.16 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.3 (demeter.kernel.org [140.211.167.41]); Wed, 25 Aug 2010 21:59:21 +0000 (UTC) diff --git a/include/linux/time.h b/include/linux/time.h index ea3559f..5d04108 100644 --- a/include/linux/time.h +++ b/include/linux/time.h @@ -145,6 +145,7 @@ extern void getnstimeofday(struct timespec *tv); extern void getrawmonotonic(struct timespec *ts); extern void getboottime(struct timespec *ts); extern void monotonic_to_bootbased(struct timespec *ts); +extern s64 getnsboottime(void); extern struct timespec timespec_trunc(struct timespec t, unsigned gran); extern int timekeeping_valid_for_hres(void); diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index caf8d4d..d250f0a 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -285,6 +285,33 @@ void ktime_get_ts(struct timespec *ts) } EXPORT_SYMBOL_GPL(ktime_get_ts); + +/** + * getnsboottime - get the bootbased clock in nsec format + * + * The function calculates the bootbased clock from the realtime + * clock and the wall_to_monotonic offset and stores the result + * in normalized timespec format in the variable pointed to by @ts. + */ +s64 getnsboottime(void) +{ + unsigned int seq; + s64 secs, nsecs; + + WARN_ON(timekeeping_suspended); + + do { + seq = read_seqbegin(&xtime_lock); + secs = xtime.tv_sec + wall_to_monotonic.tv_sec; + secs += total_sleep_time.tv_sec; + nsecs = xtime.tv_nsec + wall_to_monotonic.tv_nsec; + nsecs += total_sleep_time.tv_nsec + timekeeping_get_ns(); + + } while (read_seqretry(&xtime_lock, seq)); + return nsecs + (secs * NSEC_PER_SEC); +} +EXPORT_SYMBOL_GPL(getnsboottime); + /** * do_gettimeofday - Returns the time of day in a timeval * @tv: pointer to the timeval to be set