Commit-ID: 38669ba205d178d2d38bfd194a196d65a44d5af2 Gitweb: https://git.kernel.org/tip/38669ba205d178d2d38bfd194a196d65a44d5af2 Author: Pavel Tatashin <pasha.tatas...@oracle.com> AuthorDate: Thu, 19 Jul 2018 16:55:32 -0400 Committer: Thomas Gleixner <t...@linutronix.de> CommitDate: Fri, 20 Jul 2018 00:02:40 +0200
x86/xen/time: Output xen sched_clock time from 0 It is expected for sched_clock() to output data from 0, when system boots. Add an offset xen_sched_clock_offset (similarly how it is done in other hypervisors i.e. kvm_sched_clock_offset) to count sched_clock() from 0, when time is first initialized. Signed-off-by: Pavel Tatashin <pasha.tatas...@oracle.com> Signed-off-by: Thomas Gleixner <t...@linutronix.de> Cc: steven.sist...@oracle.com Cc: daniel.m.jor...@oracle.com Cc: li...@armlinux.org.uk Cc: schwidef...@de.ibm.com Cc: heiko.carst...@de.ibm.com Cc: john.stu...@linaro.org Cc: sb...@codeaurora.org Cc: h...@zytor.com Cc: douly.f...@cn.fujitsu.com Cc: pet...@infradead.org Cc: pra...@redhat.com Cc: feng.t...@intel.com Cc: pmla...@suse.com Cc: gno...@lxorguk.ukuu.org.uk Cc: linux-s...@vger.kernel.org Cc: boris.ostrov...@oracle.com Cc: jgr...@suse.com Cc: pbonz...@redhat.com Link: https://lkml.kernel.org/r/20180719205545.16512-14-pasha.tatas...@oracle.com --- arch/x86/xen/time.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c index 53bb7a8d10b5..c84f1e039d84 100644 --- a/arch/x86/xen/time.c +++ b/arch/x86/xen/time.c @@ -31,6 +31,8 @@ /* Xen may fire a timer up to this many ns early */ #define TIMER_SLOP 100000 +static u64 xen_sched_clock_offset __read_mostly; + /* Get the TSC speed from Xen */ static unsigned long xen_tsc_khz(void) { @@ -57,6 +59,11 @@ static u64 xen_clocksource_get_cycles(struct clocksource *cs) return xen_clocksource_read(); } +static u64 xen_sched_clock(void) +{ + return xen_clocksource_read() - xen_sched_clock_offset; +} + static void xen_read_wallclock(struct timespec64 *ts) { struct shared_info *s = HYPERVISOR_shared_info; @@ -367,7 +374,7 @@ void xen_timer_resume(void) } static const struct pv_time_ops xen_time_ops __initconst = { - .sched_clock = xen_clocksource_read, + .sched_clock = xen_sched_clock, .steal_clock = xen_steal_clock, }; @@ -505,6 +512,7 @@ static void __init xen_time_init(void) void __init xen_init_time_ops(void) { + xen_sched_clock_offset = xen_clocksource_read(); pv_time_ops = xen_time_ops; x86_init.timers.timer_init = xen_time_init; @@ -546,6 +554,7 @@ void __init xen_hvm_init_time_ops(void) return; } + xen_sched_clock_offset = xen_clocksource_read(); pv_time_ops = xen_time_ops; x86_init.timers.setup_percpu_clockev = xen_time_init; x86_cpuinit.setup_percpu_clockev = xen_hvm_setup_cpu_clockevents;
