Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754625AbbKMN6n (ORCPT ); Fri, 13 Nov 2015 08:58:43 -0500 Received: from smtp02.citrix.com ([66.165.176.63]:14800 "EHLO SMTP02.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753518AbbKMN6l (ORCPT ); Fri, 13 Nov 2015 08:58:41 -0500 X-IronPort-AV: E=Sophos;i="5.20,287,1444694400"; d="scan'208";a="317927258" Message-ID: <5645EC27.3000104@citrix.com> Date: Fri, 13 Nov 2015 13:56:55 +0000 From: Julien Grall User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Icedove/31.8.0 MIME-Version: 1.0 To: Stefano Stabellini , CC: , Arnd Bergmann , , Subject: Re: [Xen-devel] [PATCH v4 6/7] xen/arm: set the system time in Xen via the XENPF_settime64 hypercall References: <1447349448-22610-6-git-send-email-stefano.stabellini@eu.citrix.com> In-Reply-To: <1447349448-22610-6-git-send-email-stefano.stabellini@eu.citrix.com> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit X-DLP: MIA2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2365 Lines: 81 On 12/11/15 17:30, Stefano Stabellini wrote: > +static int xen_pvclock_gtod_notify(struct notifier_block *nb, > + unsigned long was_set, void *priv) > +{ > + /* Protected by the calling core code serialization */ > + static struct timespec64 next_sync; > + > + struct xen_platform_op op; > + struct timespec64 now, system_time; > + struct timekeeper *tk = priv; > + > + now.tv_sec = tk->xtime_sec; > + now.tv_nsec = (long)(tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift); > + system_time = timespec64_add(now, tk->wall_to_monotonic); > + > + /* > + * We only take the expensive HV call when the clock was set > + * or when the 11 minutes RTC synchronization time elapsed. > + */ > + if (!was_set && timespec64_compare(&now, &next_sync) < 0) > + return NOTIFY_OK; > + > + op.interface_version = XENPF_INTERFACE_VERSION; > + op.cmd = XENPF_settime64; > + op.u.settime64.mbz = 0; > + op.u.settime64.secs = now.tv_sec; > + op.u.settime64.nsecs = now.tv_nsec; > + op.u.settime64.system_time = timespec64_to_ns(&system_time); > + printk("GTOD: Setting to %llu.%09u at %llu\n", > + op.u.settime64.secs, > + op.u.settime64.nsecs, > + op.u.settime64.system_time); Is this printk really useful? > + (void)HYPERVISOR_platform_op(&op); > + > + /* > + * Move the next drift compensation time 11 minutes > + * ahead. That's emulating the sync_cmos_clock() update for > + * the hardware RTC. > + */ > + next_sync = now; > + next_sync.tv_sec += 11 * 60; > + > + return NOTIFY_OK; > +} > + > +static struct notifier_block xen_pvclock_gtod_notifier = { > + .notifier_call = xen_pvclock_gtod_notify, > +}; > + > static void xen_percpu_init(void) > { > struct vcpu_register_vcpu_info info; > @@ -313,7 +364,9 @@ static int __init xen_guest_init(void) > > pv_time_ops.steal_clock = xen_stolen_accounting; > static_key_slow_inc(¶virt_steal_enabled); > - > + if (xen_initial_domain()) > + pvclock_gtod_register_notifier(&xen_pvclock_gtod_notifier); > + I think, you've introduced a trailing whitespace. > return 0; > } > early_initcall(xen_guest_init); > Regards, -- Julien Grall -- 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/