From: guangrong.xiao@gmail.com To: pbonzini@redhat.com, mst@redhat.com, mtosatti@redhat.com Cc: qemu-devel@nongnu.org, kvm@vger.kernel.org, yunfangtai@tencent.com, Xiao Guangrong <xiaoguangrong@tencent.com> Subject: [PATCH v3 1/5] mc146818rtc: update periodic timer only if it is needed Date: Wed, 10 May 2017 16:32:55 +0800 [thread overview] Message-ID: <20170510083259.3900-2-xiaoguangrong@tencent.com> (raw) In-Reply-To: <20170510083259.3900-1-xiaoguangrong@tencent.com> From: Xiao Guangrong <xiaoguangrong@tencent.com> Currently, the timer is updated whenever RegA or RegB is written even if the periodic timer related configuration is not changed This patch optimizes it slightly to make the update happen only if its period or enable-status is changed, also later patches are depend on this optimization Signed-off-by: Xiao Guangrong <xiaoguangrong@tencent.com> --- hw/timer/mc146818rtc.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) diff --git a/hw/timer/mc146818rtc.c b/hw/timer/mc146818rtc.c index 4165450..5cccb2a 100644 --- a/hw/timer/mc146818rtc.c +++ b/hw/timer/mc146818rtc.c @@ -391,6 +391,7 @@ static void cmos_ioport_write(void *opaque, hwaddr addr, uint64_t data, unsigned size) { RTCState *s = opaque; + bool update_periodic_timer; if ((addr & 1) == 0) { s->cmos_index = data & 0x7f; @@ -423,6 +424,8 @@ static void cmos_ioport_write(void *opaque, hwaddr addr, } break; case RTC_REG_A: + update_periodic_timer = (s->cmos_data[RTC_REG_A] ^ data) & 0x0f; + if ((data & 0x60) == 0x60) { if (rtc_running(s)) { rtc_update_time(s); @@ -445,10 +448,17 @@ static void cmos_ioport_write(void *opaque, hwaddr addr, /* UIP bit is read only */ s->cmos_data[RTC_REG_A] = (data & ~REG_A_UIP) | (s->cmos_data[RTC_REG_A] & REG_A_UIP); - periodic_timer_update(s, qemu_clock_get_ns(rtc_clock)); + + if (update_periodic_timer) { + periodic_timer_update(s, qemu_clock_get_ns(rtc_clock)); + } + check_update_timer(s); break; case RTC_REG_B: + update_periodic_timer = (s->cmos_data[RTC_REG_B] ^ data) + & REG_B_PIE; + if (data & REG_B_SET) { /* update cmos to when the rtc was stopping */ if (rtc_running(s)) { @@ -475,7 +485,11 @@ static void cmos_ioport_write(void *opaque, hwaddr addr, qemu_irq_lower(s->irq); } s->cmos_data[RTC_REG_B] = data; - periodic_timer_update(s, qemu_clock_get_ns(rtc_clock)); + + if (update_periodic_timer) { + periodic_timer_update(s, qemu_clock_get_ns(rtc_clock)); + } + check_update_timer(s); break; case RTC_REG_C: -- 2.9.3
WARNING: multiple messages have this Message-ID (diff)
From: guangrong.xiao@gmail.com To: pbonzini@redhat.com, mst@redhat.com, mtosatti@redhat.com Cc: qemu-devel@nongnu.org, kvm@vger.kernel.org, yunfangtai@tencent.com, Xiao Guangrong <xiaoguangrong@tencent.com> Subject: [Qemu-devel] [PATCH v3 1/5] mc146818rtc: update periodic timer only if it is needed Date: Wed, 10 May 2017 16:32:55 +0800 [thread overview] Message-ID: <20170510083259.3900-2-xiaoguangrong@tencent.com> (raw) In-Reply-To: <20170510083259.3900-1-xiaoguangrong@tencent.com> From: Xiao Guangrong <xiaoguangrong@tencent.com> Currently, the timer is updated whenever RegA or RegB is written even if the periodic timer related configuration is not changed This patch optimizes it slightly to make the update happen only if its period or enable-status is changed, also later patches are depend on this optimization Signed-off-by: Xiao Guangrong <xiaoguangrong@tencent.com> --- hw/timer/mc146818rtc.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) diff --git a/hw/timer/mc146818rtc.c b/hw/timer/mc146818rtc.c index 4165450..5cccb2a 100644 --- a/hw/timer/mc146818rtc.c +++ b/hw/timer/mc146818rtc.c @@ -391,6 +391,7 @@ static void cmos_ioport_write(void *opaque, hwaddr addr, uint64_t data, unsigned size) { RTCState *s = opaque; + bool update_periodic_timer; if ((addr & 1) == 0) { s->cmos_index = data & 0x7f; @@ -423,6 +424,8 @@ static void cmos_ioport_write(void *opaque, hwaddr addr, } break; case RTC_REG_A: + update_periodic_timer = (s->cmos_data[RTC_REG_A] ^ data) & 0x0f; + if ((data & 0x60) == 0x60) { if (rtc_running(s)) { rtc_update_time(s); @@ -445,10 +448,17 @@ static void cmos_ioport_write(void *opaque, hwaddr addr, /* UIP bit is read only */ s->cmos_data[RTC_REG_A] = (data & ~REG_A_UIP) | (s->cmos_data[RTC_REG_A] & REG_A_UIP); - periodic_timer_update(s, qemu_clock_get_ns(rtc_clock)); + + if (update_periodic_timer) { + periodic_timer_update(s, qemu_clock_get_ns(rtc_clock)); + } + check_update_timer(s); break; case RTC_REG_B: + update_periodic_timer = (s->cmos_data[RTC_REG_B] ^ data) + & REG_B_PIE; + if (data & REG_B_SET) { /* update cmos to when the rtc was stopping */ if (rtc_running(s)) { @@ -475,7 +485,11 @@ static void cmos_ioport_write(void *opaque, hwaddr addr, qemu_irq_lower(s->irq); } s->cmos_data[RTC_REG_B] = data; - periodic_timer_update(s, qemu_clock_get_ns(rtc_clock)); + + if (update_periodic_timer) { + periodic_timer_update(s, qemu_clock_get_ns(rtc_clock)); + } + check_update_timer(s); break; case RTC_REG_C: -- 2.9.3
next prev parent reply other threads:[~2017-05-10 8:33 UTC|newest] Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top 2017-05-10 8:32 [PATCH v3 0/5] mc146818rtc: fix Windows VM clock faster guangrong.xiao 2017-05-10 8:32 ` [Qemu-devel] " guangrong.xiao 2017-05-10 8:32 ` guangrong.xiao [this message] 2017-05-10 8:32 ` [Qemu-devel] [PATCH v3 1/5] mc146818rtc: update periodic timer only if it is needed guangrong.xiao 2017-05-10 8:32 ` [PATCH v3 2/5] mc146818rtc: precisely count the clock for periodic timer guangrong.xiao 2017-05-10 8:32 ` [Qemu-devel] " guangrong.xiao 2017-05-10 8:32 ` [PATCH v3 3/5] mc146818rtc: ensure LOST_TICK_POLICY_SLEW is only enabled on TARGET_I386 guangrong.xiao 2017-05-10 8:32 ` [Qemu-devel] " guangrong.xiao 2017-05-13 22:13 ` Philippe Mathieu-Daudé 2017-05-10 8:32 ` [PATCH v3 4/5] mc146818rtc: drop unnecessary '#ifdef TARGET_I386' guangrong.xiao 2017-05-10 8:32 ` [Qemu-devel] " guangrong.xiao 2017-05-13 22:12 ` Philippe Mathieu-Daudé 2017-05-10 8:32 ` [PATCH v3 5/5] mc146818rtc: embrace all x86 specific code guangrong.xiao 2017-05-10 8:32 ` [Qemu-devel] " guangrong.xiao 2017-05-10 9:53 ` [PATCH v3 0/5] mc146818rtc: fix Windows VM clock faster Paolo Bonzini 2017-05-10 9:53 ` [Qemu-devel] " Paolo Bonzini 2017-05-18 2:26 ` Xiao Guangrong 2017-05-18 2:26 ` [Qemu-devel] " Xiao Guangrong 2017-05-18 7:52 ` Paolo Bonzini 2017-05-18 13:38 ` Xiao Guangrong 2017-05-18 13:51 ` Paolo Bonzini 2017-05-10 10:04 ` no-reply
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