From: Joao Martins <joao.m.martins@oracle.com> To: xen-devel@lists.xen.org Cc: Andrew Cooper <andrew.cooper3@citrix.com>, Joao Martins <joao.m.martins@oracle.com>, Keir Fraser <keir@xen.org>, Jan Beulich <jbeulich@suse.com> Subject: [PATCH 4/5] x86/time: refactor read_platform_stime() Date: Thu, 17 Mar 2016 09:12:15 -0700 (PDT) [thread overview] Message-ID: <1458231136-13457-5-git-send-email-joao.m.martins@oracle.com> (raw) In-Reply-To: <1458231136-13457-1-git-send-email-joao.m.martins@oracle.com> To fetch the last read from the clocksource which was used to calculate system_time. In the case of clocksource=tsc we will use it to set tsc_timestamp. Signed-off-by: Joao Martins <joao.m.martins@oracle.com> --- Cc: Keir Fraser <keir@xen.org> Cc: Jan Beulich <jbeulich@suse.com> Cc: Andrew Cooper <andrew.cooper3@citrix.com> --- xen/arch/x86/time.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) diff --git a/xen/arch/x86/time.c b/xen/arch/x86/time.c index 5af8902..89c35d0 100644 --- a/xen/arch/x86/time.c +++ b/xen/arch/x86/time.c @@ -508,6 +508,7 @@ static s_time_t stime_platform_stamp; /* System time at below platform time */ static u64 platform_timer_stamp; /* Platform time at above system time */ static u64 plt_stamp64; /* 64-bit platform counter stamp */ static u64 plt_stamp; /* hardware-width platform counter stamp */ +static u64 plt_stamp_counter; /* last read since read_counter */ static struct timer plt_overflow_timer; static s_time_t __read_platform_stime(u64 platform_time) @@ -566,7 +567,7 @@ static void plt_overflow(void *unused) set_timer(&plt_overflow_timer, NOW() + plt_overflow_period); } -static s_time_t read_platform_stime(void) +static s_time_t read_platform_stime(u64 *stamp) { u64 count; s_time_t stime; @@ -574,8 +575,11 @@ static s_time_t read_platform_stime(void) ASSERT(!local_irq_is_enabled()); spin_lock(&platform_timer_lock); - count = plt_stamp64 + ((plt_src.read_counter() - plt_stamp) & plt_mask); + plt_stamp_counter = plt_src.read_counter(); + count = plt_stamp64 + ((plt_stamp_counter - plt_stamp) & plt_mask); stime = __read_platform_stime(count); + if (stamp) + *stamp = plt_stamp_counter; spin_unlock(&platform_timer_lock); return stime; @@ -693,7 +697,7 @@ void cstate_restore_tsc(void) if ( boot_cpu_has(X86_FEATURE_NONSTOP_TSC) ) return; - write_tsc(stime2tsc(read_platform_stime())); + write_tsc(stime2tsc(read_platform_stime(NULL))); } /*************************************************************************** @@ -1012,7 +1016,7 @@ int cpu_frequency_change(u64 freq) local_irq_disable(); /* Platform time /first/, as we may be delayed by platform_timer_lock. */ - t->stime_master_stamp = read_platform_stime(); + t->stime_master_stamp = read_platform_stime(NULL); /* TSC-extrapolated time may be bogus after frequency change. */ /*t->stime_local_stamp = get_s_time();*/ t->stime_local_stamp = t->stime_master_stamp; @@ -1330,7 +1334,7 @@ static void time_calibration_tsc_rendezvous(void *_r) if ( r->master_stime == 0 ) { - r->master_stime = read_platform_stime(); + r->master_stime = read_platform_stime(NULL); r->master_tsc_stamp = rdtsc(); } atomic_inc(&r->semaphore); @@ -1422,7 +1426,7 @@ void init_percpu_time(void) local_irq_save(flags); t->local_tsc_stamp = rdtsc(); - now = read_platform_stime(); + now = read_platform_stime(NULL); local_irq_restore(flags); t->stime_master_stamp = now; -- 2.1.4 _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
next prev parent reply other threads:[~2016-03-17 16:12 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 2016-03-21 11:45 ` Joao Martins 2016-03-17 16:12 ` Joao Martins [this message] 2016-03-18 20:34 ` [PATCH 4/5] x86/time: refactor read_platform_stime() 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
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=1458231136-13457-5-git-send-email-joao.m.martins@oracle.com \ --to=joao.m.martins@oracle.com \ --cc=andrew.cooper3@citrix.com \ --cc=jbeulich@suse.com \ --cc=keir@xen.org \ --cc=xen-devel@lists.xen.org \ --subject='Re: [PATCH 4/5] x86/time: refactor read_platform_stime()' \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: link
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for NNTP newsgroup(s).