From: Andrew Cooper <andrew.cooper3@citrix.com> To: Joao Martins <joao.m.martins@oracle.com>, xen-devel@lists.xen.org Cc: Keir Fraser <keir@xen.org>, Jan Beulich <jbeulich@suse.com> Subject: Re: [PATCH 3/5] x86/time: streamline platform time init on plt_init() Date: Fri, 18 Mar 2016 20:32:48 +0000 [thread overview] Message-ID: <56EC65F0.3090607@citrix.com> (raw) In-Reply-To: <1458231136-13457-4-git-send-email-joao.m.martins@oracle.com> On 17/03/16 16:12, Joao Martins wrote: > And use to initialize platform time solely for clocksource=tsc, > as opposed to initializing platform overflow timer, which would > only fire in ~180 years (on 2.2 Ghz Broadwell processor). > > Signed-off-by: Joao Martins <joao.m.martins@oracle.com> Again, just style corrections. Reviewed-by Andrew Cooper <andrew.cooper3@citrix.com> > diff --git a/xen/arch/x86/time.c b/xen/arch/x86/time.c > index 1311c58..5af8902 100644 > --- a/xen/arch/x86/time.c > +++ b/xen/arch/x86/time.c > @@ -434,6 +434,7 @@ uint64_t ns_to_acpi_pm_tick(uint64_t ns) > /************************************************************ > * PLATFORM TIMER 4: TSC > */ > +static bool_t clocksource_is_tsc = 0; No need to explicitly initialise to 0. > static u64 tsc_freq; > static unsigned long tsc_max_warp; > static void tsc_check_reliability(void); > @@ -466,7 +467,7 @@ static int __init init_tsctimer(struct platform_timesource *pts) > } > > pts->frequency = tsc_freq; > - return tsc_reliable; > + return ( clocksource_is_tsc = tsc_reliable ); While this does work, please avoid mixing an assignment and a return. Something like pts->frequency = tsc_freq; clocksource_is_tsc = tsc_reliable; return tsc_reliable; is fine and easier logic to read. > @@ -633,11 +648,22 @@ static void __init init_platform_timer(void) > > set_time_scale(&plt_scale, pts->frequency); > > - plt_overflow_period = scale_delta( > - 1ull << (pts->counter_bits-1), &plt_scale); > - init_timer(&plt_overflow_timer, plt_overflow, NULL, 0); > plt_src = *pts; > - plt_overflow(NULL); > + > + if ( clocksource_is_tsc ) > + { > + plt_init(); > + } > + else > + { > + plt_overflow_period = scale_delta( > + 1ull << (pts->counter_bits-1), &plt_scale); As you are moving this codeblock, please fix the style to (pts->counter_bits - 1) ~Andrew _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
next prev parent reply other threads:[~2016-03-18 20:32 UTC|newest] Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top 2016-03-17 16:12 [PATCH 0/5] x86/time: PVCLOCK_TSC_STABLE_BIT support Joao Martins 2016-03-17 16:12 ` [PATCH 1/5] public/xen.h: add flags field to vcpu_time_info Joao Martins 2016-03-18 20:12 ` Andrew Cooper 2016-03-21 11:42 ` Joao Martins 2016-03-21 11:43 ` Andrew Cooper 2016-03-21 11:51 ` Joao Martins 2016-03-21 15:10 ` Jan Beulich 2016-03-21 15:27 ` Andrew Cooper 2016-03-21 15:40 ` Joao Martins 2016-03-17 16:12 ` [PATCH 2/5] x86/time: implement tsc as clocksource Joao Martins 2016-03-18 20:21 ` Andrew Cooper 2016-03-21 11:43 ` Joao Martins 2016-03-22 12:41 ` Joao Martins 2016-03-22 12:46 ` Jan Beulich 2016-03-22 15:51 ` Joao Martins 2016-03-22 16:02 ` Jan Beulich 2016-03-22 20:40 ` Joao Martins 2016-03-23 7:28 ` Jan Beulich 2016-03-23 12:05 ` Joao Martins 2016-03-23 14:05 ` Jan Beulich 2016-03-17 16:12 ` [PATCH 3/5] x86/time: streamline platform time init on plt_init() Joao Martins 2016-03-18 20:32 ` Andrew Cooper [this message] 2016-03-21 11:45 ` Joao Martins 2016-03-17 16:12 ` [PATCH 4/5] x86/time: refactor read_platform_stime() Joao Martins 2016-03-18 20:34 ` Andrew Cooper 2016-03-21 11:45 ` Joao Martins 2016-03-21 13:08 ` Andrew Cooper 2016-03-17 16:12 ` [PATCH 5/5] x86/time: implement PVCLOCK_TSC_STABLE_BIT Joao Martins 2016-03-18 20:58 ` Andrew Cooper 2016-03-21 11:50 ` Joao Martins
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