From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965843Ab3E2LD4 (ORCPT ); Wed, 29 May 2013 07:03:56 -0400 Received: from smtp.citrix.com ([66.165.176.89]:35866 "EHLO SMTP.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965804Ab3E2LDq (ORCPT ); Wed, 29 May 2013 07:03:46 -0400 X-IronPort-AV: E=Sophos;i="4.87,763,1363132800"; d="scan'208";a="27941724" Date: Wed, 29 May 2013 12:03:26 +0100 From: Stefano Stabellini X-X-Sender: sstabellini@kaball.uk.xensource.com To: Konrad Rzeszutek Wilk CC: Stefano Stabellini , , , , , , Subject: Re: [PATCH v4 1/4] xen: move xen_setup_runstate_info and get_runstate_snapshot to drivers/xen/time.c In-Reply-To: <20130528181515.GB27718@phenom.dumpdata.com> Message-ID: References: <1369763672-12919-1-git-send-email-stefano.stabellini@eu.citrix.com> <20130528181515.GB27718@phenom.dumpdata.com> User-Agent: Alpine 2.02 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 28 May 2013, Konrad Rzeszutek Wilk wrote: > On Tue, May 28, 2013 at 06:54:29PM +0100, Stefano Stabellini wrote: > > Signed-off-by: Stefano Stabellini > > Acked-by: Ian Campbell > > CC: konrad.wilk@oracle.com > > > > Changes in v2: > > - leave do_stolen_accounting in arch/x86/xen/time.c; > > - use the new common functions in arch/ia64/xen/time.c. > > So you also modify the function. do_stolen_accounting? Just enought to call the new common function xen_get_runstate_snapshot instead of the old x86 specific get_runstate_snapshot. > > --- > > arch/ia64/xen/time.c | 48 +++---------------------- > > arch/x86/xen/time.c | 76 +---------------------------------------- > > drivers/xen/Makefile | 2 +- > > drivers/xen/time.c | 91 +++++++++++++++++++++++++++++++++++++++++++++++++ > > include/xen/xen-ops.h | 5 +++ > > 5 files changed, 104 insertions(+), 118 deletions(-) > > create mode 100644 drivers/xen/time.c > > > > diff --git a/arch/ia64/xen/time.c b/arch/ia64/xen/time.c > > index 1f8244a..79a0b8c 100644 > > --- a/arch/ia64/xen/time.c > > +++ b/arch/ia64/xen/time.c > > @@ -34,53 +34,17 @@ > > > > #include "../kernel/fsyscall_gtod_data.h" > > > > -static DEFINE_PER_CPU(struct vcpu_runstate_info, xen_runstate); > > static DEFINE_PER_CPU(unsigned long, xen_stolen_time); > > static DEFINE_PER_CPU(unsigned long, xen_blocked_time); > > > > /* taken from i386/kernel/time-xen.c */ > > static void xen_init_missing_ticks_accounting(int cpu) > > { > > - struct vcpu_register_runstate_memory_area area; > > - struct vcpu_runstate_info *runstate = &per_cpu(xen_runstate, cpu); > > - int rc; > > + xen_setup_runstate_info(&runstate); > > > > - memset(runstate, 0, sizeof(*runstate)); > > - > > - area.addr.v = runstate; > > - rc = HYPERVISOR_vcpu_op(VCPUOP_register_runstate_memory_area, cpu, > > - &area); > > - WARN_ON(rc && rc != -ENOSYS); > > - > > - per_cpu(xen_blocked_time, cpu) = runstate->time[RUNSTATE_blocked]; > > - per_cpu(xen_stolen_time, cpu) = runstate->time[RUNSTATE_runnable] > > - + runstate->time[RUNSTATE_offline]; > > -} > > - > > -/* > > - * Runstate accounting > > - */ > > -/* stolen from arch/x86/xen/time.c */ > > -static void get_runstate_snapshot(struct vcpu_runstate_info *res) > > -{ > > - u64 state_time; > > - struct vcpu_runstate_info *state; > > - > > - BUG_ON(preemptible()); > > - > > - state = &__get_cpu_var(xen_runstate); > > - > > - /* > > - * The runstate info is always updated by the hypervisor on > > - * the current CPU, so there's no need to use anything > > - * stronger than a compiler barrier when fetching it. > > - */ > > - do { > > - state_time = state->state_entry_time; > > - rmb(); > > - *res = *state; > > - rmb(); > > - } while (state->state_entry_time != state_time); > > + per_cpu(xen_blocked_time, cpu) = runstate.time[RUNSTATE_blocked]; > > + per_cpu(xen_stolen_time, cpu) = runstate.time[RUNSTATE_runnable] > > + + runstate.time[RUNSTATE_offline]; > > } > > > > #define NS_PER_TICK (1000000000LL/HZ) > > @@ -94,7 +58,7 @@ consider_steal_time(unsigned long new_itm) > > struct vcpu_runstate_info runstate; > > struct task_struct *p = current; > > > > - get_runstate_snapshot(&runstate); > > + xen_get_runstate_snapshot(&runstate); > > > > /* > > * Check for vcpu migration effect > > @@ -202,7 +166,7 @@ static unsigned long long xen_sched_clock(void) > > */ > > now = ia64_native_sched_clock(); > > > > - get_runstate_snapshot(&runstate); > > + xen_get_runstate_snapshot(&runstate); > > > > WARN_ON(runstate.state != RUNSTATE_running); > > > > diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c > > index 3d88bfd..c0ca15e 100644 > > --- a/arch/x86/xen/time.c > > +++ b/arch/x86/xen/time.c > > @@ -30,9 +30,6 @@ > > #define TIMER_SLOP 100000 > > #define NS_PER_TICK (1000000000LL / HZ) > > > > -/* runstate info updated by Xen */ > > -static DEFINE_PER_CPU(struct vcpu_runstate_info, xen_runstate); > > - > > /* snapshots of runstate info */ > > static DEFINE_PER_CPU(struct vcpu_runstate_info, xen_runstate_snapshot); > > > > @@ -40,77 +37,6 @@ static DEFINE_PER_CPU(struct vcpu_runstate_info, xen_runstate_snapshot); > > static DEFINE_PER_CPU(u64, xen_residual_stolen); > > static DEFINE_PER_CPU(u64, xen_residual_blocked); > > > > -/* return an consistent snapshot of 64-bit time/counter value */ > > -static u64 get64(const u64 *p) > > -{ > > - u64 ret; > > - > > - if (BITS_PER_LONG < 64) { > > - u32 *p32 = (u32 *)p; > > - u32 h, l; > > - > > - /* > > - * Read high then low, and then make sure high is > > - * still the same; this will only loop if low wraps > > - * and carries into high. > > - * XXX some clean way to make this endian-proof? > > - */ > > - do { > > - h = p32[1]; > > - barrier(); > > - l = p32[0]; > > - barrier(); > > - } while (p32[1] != h); > > - > > - ret = (((u64)h) << 32) | l; > > - } else > > - ret = *p; > > - > > - return ret; > > -} > > - > > -/* > > - * Runstate accounting > > - */ > > -static void get_runstate_snapshot(struct vcpu_runstate_info *res) > > -{ > > - u64 state_time; > > - struct vcpu_runstate_info *state; > > - > > - BUG_ON(preemptible()); > > - > > - state = &__get_cpu_var(xen_runstate); > > - > > - /* > > - * The runstate info is always updated by the hypervisor on > > - * the current CPU, so there's no need to use anything > > - * stronger than a compiler barrier when fetching it. > > - */ > > - do { > > - state_time = get64(&state->state_entry_time); > > - barrier(); > > - *res = *state; > > - barrier(); > > - } while (get64(&state->state_entry_time) != state_time); > > -} > > - > > -/* return true when a vcpu could run but has no real cpu to run on */ > > -bool xen_vcpu_stolen(int vcpu) > > -{ > > - return per_cpu(xen_runstate, vcpu).state == RUNSTATE_runnable; > > -} > > - > > -void xen_setup_runstate_info(int cpu) > > -{ > > - struct vcpu_register_runstate_memory_area area; > > - > > - area.addr.v = &per_cpu(xen_runstate, cpu); > > - > > - if (HYPERVISOR_vcpu_op(VCPUOP_register_runstate_memory_area, > > - cpu, &area)) > > - BUG(); > > -} > > - > > static void do_stolen_accounting(void) > > { > > struct vcpu_runstate_info state; > > @@ -118,7 +44,7 @@ static void do_stolen_accounting(void) > > s64 blocked, runnable, offline, stolen; > > cputime_t ticks; > > > > - get_runstate_snapshot(&state); > > + xen_get_runstate_snapshot(&state); > > > > WARN_ON(state.state != RUNSTATE_running); > > > > diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile > > index eabd0ee..2bf461a 100644 > > --- a/drivers/xen/Makefile > > +++ b/drivers/xen/Makefile > > @@ -3,7 +3,7 @@ obj-y += manage.o > > obj-$(CONFIG_HOTPLUG_CPU) += cpu_hotplug.o > > endif > > obj-$(CONFIG_X86) += fallback.o > > -obj-y += grant-table.o features.o events.o balloon.o > > +obj-y += grant-table.o features.o events.o balloon.o time.o > > obj-y += xenbus/ > > > > nostackp := $(call cc-option, -fno-stack-protector) > > diff --git a/drivers/xen/time.c b/drivers/xen/time.c > > new file mode 100644 > > index 0000000..c2e39d3 > > --- /dev/null > > +++ b/drivers/xen/time.c > > @@ -0,0 +1,91 @@ > > +/* > > + * Xen stolen ticks accounting. > > + */ > > +#include > > +#include > > +#include > > +#include > > + > > +#include > > +#include > > + > > +#include > > +#include > > +#include > > +#include > > +#include > > + > > +/* runstate info updated by Xen */ > > +static DEFINE_PER_CPU(struct vcpu_runstate_info, xen_runstate); > > + > > +/* return an consistent snapshot of 64-bit time/counter value */ > > +static u64 get64(const u64 *p) > > +{ > > + u64 ret; > > + > > + if (BITS_PER_LONG < 64) { > > + u32 *p32 = (u32 *)p; > > + u32 h, l; > > + > > + /* > > + * Read high then low, and then make sure high is > > + * still the same; this will only loop if low wraps > > + * and carries into high. > > + * XXX some clean way to make this endian-proof? > > + */ > > + do { > > + h = p32[1]; > > + barrier(); > > + l = p32[0]; > > + barrier(); > > + } while (p32[1] != h); > > + > > + ret = (((u64)h) << 32) | l; > > + } else > > + ret = *p; > > + > > + return ret; > > +} > > + > > +/* > > + * Runstate accounting > > + */ > > +void xen_get_runstate_snapshot(struct vcpu_runstate_info *res) > > +{ > > + u64 state_time; > > + struct vcpu_runstate_info *state; > > + > > + BUG_ON(preemptible()); > > + > > + state = &__get_cpu_var(xen_runstate); > > + > > + /* > > + * The runstate info is always updated by the hypervisor on > > + * the current CPU, so there's no need to use anything > > + * stronger than a compiler barrier when fetching it. > > + */ > > + do { > > + state_time = get64(&state->state_entry_time); > > + barrier(); > > + *res = *state; > > + barrier(); > > + } while (get64(&state->state_entry_time) != state_time); > > +} > > + > > +/* return true when a vcpu could run but has no real cpu to run on */ > > +bool xen_vcpu_stolen(int vcpu) > > +{ > > + return per_cpu(xen_runstate, vcpu).state == RUNSTATE_runnable; > > +} > > + > > +void xen_setup_runstate_info(int cpu) > > +{ > > + struct vcpu_register_runstate_memory_area area; > > + > > + area.addr.v = &per_cpu(xen_runstate, cpu); > > + > > + if (HYPERVISOR_vcpu_op(VCPUOP_register_runstate_memory_area, > > + cpu, &area)) > > + BUG(); > > The original code did: > > - rc = HYPERVISOR_vcpu_op(VCPUOP_register_runstate_memory_area, cpu, > - &area); > - WARN_ON(rc && rc != -ENOSYS); > - > Any reason not to do this? The original x86 code just BUGs out: I took that version over the ia64 version. From mboxrd@z Thu Jan 1 00:00:00 1970 From: stefano.stabellini@eu.citrix.com (Stefano Stabellini) Date: Wed, 29 May 2013 12:03:26 +0100 Subject: [PATCH v4 1/4] xen: move xen_setup_runstate_info and get_runstate_snapshot to drivers/xen/time.c In-Reply-To: <20130528181515.GB27718@phenom.dumpdata.com> References: <1369763672-12919-1-git-send-email-stefano.stabellini@eu.citrix.com> <20130528181515.GB27718@phenom.dumpdata.com> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Tue, 28 May 2013, Konrad Rzeszutek Wilk wrote: > On Tue, May 28, 2013 at 06:54:29PM +0100, Stefano Stabellini wrote: > > Signed-off-by: Stefano Stabellini > > Acked-by: Ian Campbell > > CC: konrad.wilk at oracle.com > > > > Changes in v2: > > - leave do_stolen_accounting in arch/x86/xen/time.c; > > - use the new common functions in arch/ia64/xen/time.c. > > So you also modify the function. do_stolen_accounting? Just enought to call the new common function xen_get_runstate_snapshot instead of the old x86 specific get_runstate_snapshot. > > --- > > arch/ia64/xen/time.c | 48 +++---------------------- > > arch/x86/xen/time.c | 76 +---------------------------------------- > > drivers/xen/Makefile | 2 +- > > drivers/xen/time.c | 91 +++++++++++++++++++++++++++++++++++++++++++++++++ > > include/xen/xen-ops.h | 5 +++ > > 5 files changed, 104 insertions(+), 118 deletions(-) > > create mode 100644 drivers/xen/time.c > > > > diff --git a/arch/ia64/xen/time.c b/arch/ia64/xen/time.c > > index 1f8244a..79a0b8c 100644 > > --- a/arch/ia64/xen/time.c > > +++ b/arch/ia64/xen/time.c > > @@ -34,53 +34,17 @@ > > > > #include "../kernel/fsyscall_gtod_data.h" > > > > -static DEFINE_PER_CPU(struct vcpu_runstate_info, xen_runstate); > > static DEFINE_PER_CPU(unsigned long, xen_stolen_time); > > static DEFINE_PER_CPU(unsigned long, xen_blocked_time); > > > > /* taken from i386/kernel/time-xen.c */ > > static void xen_init_missing_ticks_accounting(int cpu) > > { > > - struct vcpu_register_runstate_memory_area area; > > - struct vcpu_runstate_info *runstate = &per_cpu(xen_runstate, cpu); > > - int rc; > > + xen_setup_runstate_info(&runstate); > > > > - memset(runstate, 0, sizeof(*runstate)); > > - > > - area.addr.v = runstate; > > - rc = HYPERVISOR_vcpu_op(VCPUOP_register_runstate_memory_area, cpu, > > - &area); > > - WARN_ON(rc && rc != -ENOSYS); > > - > > - per_cpu(xen_blocked_time, cpu) = runstate->time[RUNSTATE_blocked]; > > - per_cpu(xen_stolen_time, cpu) = runstate->time[RUNSTATE_runnable] > > - + runstate->time[RUNSTATE_offline]; > > -} > > - > > -/* > > - * Runstate accounting > > - */ > > -/* stolen from arch/x86/xen/time.c */ > > -static void get_runstate_snapshot(struct vcpu_runstate_info *res) > > -{ > > - u64 state_time; > > - struct vcpu_runstate_info *state; > > - > > - BUG_ON(preemptible()); > > - > > - state = &__get_cpu_var(xen_runstate); > > - > > - /* > > - * The runstate info is always updated by the hypervisor on > > - * the current CPU, so there's no need to use anything > > - * stronger than a compiler barrier when fetching it. > > - */ > > - do { > > - state_time = state->state_entry_time; > > - rmb(); > > - *res = *state; > > - rmb(); > > - } while (state->state_entry_time != state_time); > > + per_cpu(xen_blocked_time, cpu) = runstate.time[RUNSTATE_blocked]; > > + per_cpu(xen_stolen_time, cpu) = runstate.time[RUNSTATE_runnable] > > + + runstate.time[RUNSTATE_offline]; > > } > > > > #define NS_PER_TICK (1000000000LL/HZ) > > @@ -94,7 +58,7 @@ consider_steal_time(unsigned long new_itm) > > struct vcpu_runstate_info runstate; > > struct task_struct *p = current; > > > > - get_runstate_snapshot(&runstate); > > + xen_get_runstate_snapshot(&runstate); > > > > /* > > * Check for vcpu migration effect > > @@ -202,7 +166,7 @@ static unsigned long long xen_sched_clock(void) > > */ > > now = ia64_native_sched_clock(); > > > > - get_runstate_snapshot(&runstate); > > + xen_get_runstate_snapshot(&runstate); > > > > WARN_ON(runstate.state != RUNSTATE_running); > > > > diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c > > index 3d88bfd..c0ca15e 100644 > > --- a/arch/x86/xen/time.c > > +++ b/arch/x86/xen/time.c > > @@ -30,9 +30,6 @@ > > #define TIMER_SLOP 100000 > > #define NS_PER_TICK (1000000000LL / HZ) > > > > -/* runstate info updated by Xen */ > > -static DEFINE_PER_CPU(struct vcpu_runstate_info, xen_runstate); > > - > > /* snapshots of runstate info */ > > static DEFINE_PER_CPU(struct vcpu_runstate_info, xen_runstate_snapshot); > > > > @@ -40,77 +37,6 @@ static DEFINE_PER_CPU(struct vcpu_runstate_info, xen_runstate_snapshot); > > static DEFINE_PER_CPU(u64, xen_residual_stolen); > > static DEFINE_PER_CPU(u64, xen_residual_blocked); > > > > -/* return an consistent snapshot of 64-bit time/counter value */ > > -static u64 get64(const u64 *p) > > -{ > > - u64 ret; > > - > > - if (BITS_PER_LONG < 64) { > > - u32 *p32 = (u32 *)p; > > - u32 h, l; > > - > > - /* > > - * Read high then low, and then make sure high is > > - * still the same; this will only loop if low wraps > > - * and carries into high. > > - * XXX some clean way to make this endian-proof? > > - */ > > - do { > > - h = p32[1]; > > - barrier(); > > - l = p32[0]; > > - barrier(); > > - } while (p32[1] != h); > > - > > - ret = (((u64)h) << 32) | l; > > - } else > > - ret = *p; > > - > > - return ret; > > -} > > - > > -/* > > - * Runstate accounting > > - */ > > -static void get_runstate_snapshot(struct vcpu_runstate_info *res) > > -{ > > - u64 state_time; > > - struct vcpu_runstate_info *state; > > - > > - BUG_ON(preemptible()); > > - > > - state = &__get_cpu_var(xen_runstate); > > - > > - /* > > - * The runstate info is always updated by the hypervisor on > > - * the current CPU, so there's no need to use anything > > - * stronger than a compiler barrier when fetching it. > > - */ > > - do { > > - state_time = get64(&state->state_entry_time); > > - barrier(); > > - *res = *state; > > - barrier(); > > - } while (get64(&state->state_entry_time) != state_time); > > -} > > - > > -/* return true when a vcpu could run but has no real cpu to run on */ > > -bool xen_vcpu_stolen(int vcpu) > > -{ > > - return per_cpu(xen_runstate, vcpu).state == RUNSTATE_runnable; > > -} > > - > > -void xen_setup_runstate_info(int cpu) > > -{ > > - struct vcpu_register_runstate_memory_area area; > > - > > - area.addr.v = &per_cpu(xen_runstate, cpu); > > - > > - if (HYPERVISOR_vcpu_op(VCPUOP_register_runstate_memory_area, > > - cpu, &area)) > > - BUG(); > > -} > > - > > static void do_stolen_accounting(void) > > { > > struct vcpu_runstate_info state; > > @@ -118,7 +44,7 @@ static void do_stolen_accounting(void) > > s64 blocked, runnable, offline, stolen; > > cputime_t ticks; > > > > - get_runstate_snapshot(&state); > > + xen_get_runstate_snapshot(&state); > > > > WARN_ON(state.state != RUNSTATE_running); > > > > diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile > > index eabd0ee..2bf461a 100644 > > --- a/drivers/xen/Makefile > > +++ b/drivers/xen/Makefile > > @@ -3,7 +3,7 @@ obj-y += manage.o > > obj-$(CONFIG_HOTPLUG_CPU) += cpu_hotplug.o > > endif > > obj-$(CONFIG_X86) += fallback.o > > -obj-y += grant-table.o features.o events.o balloon.o > > +obj-y += grant-table.o features.o events.o balloon.o time.o > > obj-y += xenbus/ > > > > nostackp := $(call cc-option, -fno-stack-protector) > > diff --git a/drivers/xen/time.c b/drivers/xen/time.c > > new file mode 100644 > > index 0000000..c2e39d3 > > --- /dev/null > > +++ b/drivers/xen/time.c > > @@ -0,0 +1,91 @@ > > +/* > > + * Xen stolen ticks accounting. > > + */ > > +#include > > +#include > > +#include > > +#include > > + > > +#include > > +#include > > + > > +#include > > +#include > > +#include > > +#include > > +#include > > + > > +/* runstate info updated by Xen */ > > +static DEFINE_PER_CPU(struct vcpu_runstate_info, xen_runstate); > > + > > +/* return an consistent snapshot of 64-bit time/counter value */ > > +static u64 get64(const u64 *p) > > +{ > > + u64 ret; > > + > > + if (BITS_PER_LONG < 64) { > > + u32 *p32 = (u32 *)p; > > + u32 h, l; > > + > > + /* > > + * Read high then low, and then make sure high is > > + * still the same; this will only loop if low wraps > > + * and carries into high. > > + * XXX some clean way to make this endian-proof? > > + */ > > + do { > > + h = p32[1]; > > + barrier(); > > + l = p32[0]; > > + barrier(); > > + } while (p32[1] != h); > > + > > + ret = (((u64)h) << 32) | l; > > + } else > > + ret = *p; > > + > > + return ret; > > +} > > + > > +/* > > + * Runstate accounting > > + */ > > +void xen_get_runstate_snapshot(struct vcpu_runstate_info *res) > > +{ > > + u64 state_time; > > + struct vcpu_runstate_info *state; > > + > > + BUG_ON(preemptible()); > > + > > + state = &__get_cpu_var(xen_runstate); > > + > > + /* > > + * The runstate info is always updated by the hypervisor on > > + * the current CPU, so there's no need to use anything > > + * stronger than a compiler barrier when fetching it. > > + */ > > + do { > > + state_time = get64(&state->state_entry_time); > > + barrier(); > > + *res = *state; > > + barrier(); > > + } while (get64(&state->state_entry_time) != state_time); > > +} > > + > > +/* return true when a vcpu could run but has no real cpu to run on */ > > +bool xen_vcpu_stolen(int vcpu) > > +{ > > + return per_cpu(xen_runstate, vcpu).state == RUNSTATE_runnable; > > +} > > + > > +void xen_setup_runstate_info(int cpu) > > +{ > > + struct vcpu_register_runstate_memory_area area; > > + > > + area.addr.v = &per_cpu(xen_runstate, cpu); > > + > > + if (HYPERVISOR_vcpu_op(VCPUOP_register_runstate_memory_area, > > + cpu, &area)) > > + BUG(); > > The original code did: > > - rc = HYPERVISOR_vcpu_op(VCPUOP_register_runstate_memory_area, cpu, > - &area); > - WARN_ON(rc && rc != -ENOSYS); > - > Any reason not to do this? The original x86 code just BUGs out: I took that version over the ia64 version. From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefano Stabellini Subject: Re: [PATCH v4 1/4] xen: move xen_setup_runstate_info and get_runstate_snapshot to drivers/xen/time.c Date: Wed, 29 May 2013 12:03:26 +0100 Message-ID: References: <1369763672-12919-1-git-send-email-stefano.stabellini@eu.citrix.com> <20130528181515.GB27718@phenom.dumpdata.com> Mime-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Return-path: In-Reply-To: <20130528181515.GB27718@phenom.dumpdata.com> Sender: linux-kernel-owner@vger.kernel.org To: Konrad Rzeszutek Wilk Cc: Stefano Stabellini , xen-devel@lists.xensource.com, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, marc.zyngier@arm.com, will.deacon@arm.com, Ian.Campbell@citrix.com List-Id: xen-devel@lists.xenproject.org On Tue, 28 May 2013, Konrad Rzeszutek Wilk wrote: > On Tue, May 28, 2013 at 06:54:29PM +0100, Stefano Stabellini wrote: > > Signed-off-by: Stefano Stabellini > > Acked-by: Ian Campbell > > CC: konrad.wilk@oracle.com > > > > Changes in v2: > > - leave do_stolen_accounting in arch/x86/xen/time.c; > > - use the new common functions in arch/ia64/xen/time.c. > > So you also modify the function. do_stolen_accounting? Just enought to call the new common function xen_get_runstate_snapshot instead of the old x86 specific get_runstate_snapshot. > > --- > > arch/ia64/xen/time.c | 48 +++---------------------- > > arch/x86/xen/time.c | 76 +---------------------------------------- > > drivers/xen/Makefile | 2 +- > > drivers/xen/time.c | 91 +++++++++++++++++++++++++++++++++++++++++++++++++ > > include/xen/xen-ops.h | 5 +++ > > 5 files changed, 104 insertions(+), 118 deletions(-) > > create mode 100644 drivers/xen/time.c > > > > diff --git a/arch/ia64/xen/time.c b/arch/ia64/xen/time.c > > index 1f8244a..79a0b8c 100644 > > --- a/arch/ia64/xen/time.c > > +++ b/arch/ia64/xen/time.c > > @@ -34,53 +34,17 @@ > > > > #include "../kernel/fsyscall_gtod_data.h" > > > > -static DEFINE_PER_CPU(struct vcpu_runstate_info, xen_runstate); > > static DEFINE_PER_CPU(unsigned long, xen_stolen_time); > > static DEFINE_PER_CPU(unsigned long, xen_blocked_time); > > > > /* taken from i386/kernel/time-xen.c */ > > static void xen_init_missing_ticks_accounting(int cpu) > > { > > - struct vcpu_register_runstate_memory_area area; > > - struct vcpu_runstate_info *runstate = &per_cpu(xen_runstate, cpu); > > - int rc; > > + xen_setup_runstate_info(&runstate); > > > > - memset(runstate, 0, sizeof(*runstate)); > > - > > - area.addr.v = runstate; > > - rc = HYPERVISOR_vcpu_op(VCPUOP_register_runstate_memory_area, cpu, > > - &area); > > - WARN_ON(rc && rc != -ENOSYS); > > - > > - per_cpu(xen_blocked_time, cpu) = runstate->time[RUNSTATE_blocked]; > > - per_cpu(xen_stolen_time, cpu) = runstate->time[RUNSTATE_runnable] > > - + runstate->time[RUNSTATE_offline]; > > -} > > - > > -/* > > - * Runstate accounting > > - */ > > -/* stolen from arch/x86/xen/time.c */ > > -static void get_runstate_snapshot(struct vcpu_runstate_info *res) > > -{ > > - u64 state_time; > > - struct vcpu_runstate_info *state; > > - > > - BUG_ON(preemptible()); > > - > > - state = &__get_cpu_var(xen_runstate); > > - > > - /* > > - * The runstate info is always updated by the hypervisor on > > - * the current CPU, so there's no need to use anything > > - * stronger than a compiler barrier when fetching it. > > - */ > > - do { > > - state_time = state->state_entry_time; > > - rmb(); > > - *res = *state; > > - rmb(); > > - } while (state->state_entry_time != state_time); > > + per_cpu(xen_blocked_time, cpu) = runstate.time[RUNSTATE_blocked]; > > + per_cpu(xen_stolen_time, cpu) = runstate.time[RUNSTATE_runnable] > > + + runstate.time[RUNSTATE_offline]; > > } > > > > #define NS_PER_TICK (1000000000LL/HZ) > > @@ -94,7 +58,7 @@ consider_steal_time(unsigned long new_itm) > > struct vcpu_runstate_info runstate; > > struct task_struct *p = current; > > > > - get_runstate_snapshot(&runstate); > > + xen_get_runstate_snapshot(&runstate); > > > > /* > > * Check for vcpu migration effect > > @@ -202,7 +166,7 @@ static unsigned long long xen_sched_clock(void) > > */ > > now = ia64_native_sched_clock(); > > > > - get_runstate_snapshot(&runstate); > > + xen_get_runstate_snapshot(&runstate); > > > > WARN_ON(runstate.state != RUNSTATE_running); > > > > diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c > > index 3d88bfd..c0ca15e 100644 > > --- a/arch/x86/xen/time.c > > +++ b/arch/x86/xen/time.c > > @@ -30,9 +30,6 @@ > > #define TIMER_SLOP 100000 > > #define NS_PER_TICK (1000000000LL / HZ) > > > > -/* runstate info updated by Xen */ > > -static DEFINE_PER_CPU(struct vcpu_runstate_info, xen_runstate); > > - > > /* snapshots of runstate info */ > > static DEFINE_PER_CPU(struct vcpu_runstate_info, xen_runstate_snapshot); > > > > @@ -40,77 +37,6 @@ static DEFINE_PER_CPU(struct vcpu_runstate_info, xen_runstate_snapshot); > > static DEFINE_PER_CPU(u64, xen_residual_stolen); > > static DEFINE_PER_CPU(u64, xen_residual_blocked); > > > > -/* return an consistent snapshot of 64-bit time/counter value */ > > -static u64 get64(const u64 *p) > > -{ > > - u64 ret; > > - > > - if (BITS_PER_LONG < 64) { > > - u32 *p32 = (u32 *)p; > > - u32 h, l; > > - > > - /* > > - * Read high then low, and then make sure high is > > - * still the same; this will only loop if low wraps > > - * and carries into high. > > - * XXX some clean way to make this endian-proof? > > - */ > > - do { > > - h = p32[1]; > > - barrier(); > > - l = p32[0]; > > - barrier(); > > - } while (p32[1] != h); > > - > > - ret = (((u64)h) << 32) | l; > > - } else > > - ret = *p; > > - > > - return ret; > > -} > > - > > -/* > > - * Runstate accounting > > - */ > > -static void get_runstate_snapshot(struct vcpu_runstate_info *res) > > -{ > > - u64 state_time; > > - struct vcpu_runstate_info *state; > > - > > - BUG_ON(preemptible()); > > - > > - state = &__get_cpu_var(xen_runstate); > > - > > - /* > > - * The runstate info is always updated by the hypervisor on > > - * the current CPU, so there's no need to use anything > > - * stronger than a compiler barrier when fetching it. > > - */ > > - do { > > - state_time = get64(&state->state_entry_time); > > - barrier(); > > - *res = *state; > > - barrier(); > > - } while (get64(&state->state_entry_time) != state_time); > > -} > > - > > -/* return true when a vcpu could run but has no real cpu to run on */ > > -bool xen_vcpu_stolen(int vcpu) > > -{ > > - return per_cpu(xen_runstate, vcpu).state == RUNSTATE_runnable; > > -} > > - > > -void xen_setup_runstate_info(int cpu) > > -{ > > - struct vcpu_register_runstate_memory_area area; > > - > > - area.addr.v = &per_cpu(xen_runstate, cpu); > > - > > - if (HYPERVISOR_vcpu_op(VCPUOP_register_runstate_memory_area, > > - cpu, &area)) > > - BUG(); > > -} > > - > > static void do_stolen_accounting(void) > > { > > struct vcpu_runstate_info state; > > @@ -118,7 +44,7 @@ static void do_stolen_accounting(void) > > s64 blocked, runnable, offline, stolen; > > cputime_t ticks; > > > > - get_runstate_snapshot(&state); > > + xen_get_runstate_snapshot(&state); > > > > WARN_ON(state.state != RUNSTATE_running); > > > > diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile > > index eabd0ee..2bf461a 100644 > > --- a/drivers/xen/Makefile > > +++ b/drivers/xen/Makefile > > @@ -3,7 +3,7 @@ obj-y += manage.o > > obj-$(CONFIG_HOTPLUG_CPU) += cpu_hotplug.o > > endif > > obj-$(CONFIG_X86) += fallback.o > > -obj-y += grant-table.o features.o events.o balloon.o > > +obj-y += grant-table.o features.o events.o balloon.o time.o > > obj-y += xenbus/ > > > > nostackp := $(call cc-option, -fno-stack-protector) > > diff --git a/drivers/xen/time.c b/drivers/xen/time.c > > new file mode 100644 > > index 0000000..c2e39d3 > > --- /dev/null > > +++ b/drivers/xen/time.c > > @@ -0,0 +1,91 @@ > > +/* > > + * Xen stolen ticks accounting. > > + */ > > +#include > > +#include > > +#include > > +#include > > + > > +#include > > +#include > > + > > +#include > > +#include > > +#include > > +#include > > +#include > > + > > +/* runstate info updated by Xen */ > > +static DEFINE_PER_CPU(struct vcpu_runstate_info, xen_runstate); > > + > > +/* return an consistent snapshot of 64-bit time/counter value */ > > +static u64 get64(const u64 *p) > > +{ > > + u64 ret; > > + > > + if (BITS_PER_LONG < 64) { > > + u32 *p32 = (u32 *)p; > > + u32 h, l; > > + > > + /* > > + * Read high then low, and then make sure high is > > + * still the same; this will only loop if low wraps > > + * and carries into high. > > + * XXX some clean way to make this endian-proof? > > + */ > > + do { > > + h = p32[1]; > > + barrier(); > > + l = p32[0]; > > + barrier(); > > + } while (p32[1] != h); > > + > > + ret = (((u64)h) << 32) | l; > > + } else > > + ret = *p; > > + > > + return ret; > > +} > > + > > +/* > > + * Runstate accounting > > + */ > > +void xen_get_runstate_snapshot(struct vcpu_runstate_info *res) > > +{ > > + u64 state_time; > > + struct vcpu_runstate_info *state; > > + > > + BUG_ON(preemptible()); > > + > > + state = &__get_cpu_var(xen_runstate); > > + > > + /* > > + * The runstate info is always updated by the hypervisor on > > + * the current CPU, so there's no need to use anything > > + * stronger than a compiler barrier when fetching it. > > + */ > > + do { > > + state_time = get64(&state->state_entry_time); > > + barrier(); > > + *res = *state; > > + barrier(); > > + } while (get64(&state->state_entry_time) != state_time); > > +} > > + > > +/* return true when a vcpu could run but has no real cpu to run on */ > > +bool xen_vcpu_stolen(int vcpu) > > +{ > > + return per_cpu(xen_runstate, vcpu).state == RUNSTATE_runnable; > > +} > > + > > +void xen_setup_runstate_info(int cpu) > > +{ > > + struct vcpu_register_runstate_memory_area area; > > + > > + area.addr.v = &per_cpu(xen_runstate, cpu); > > + > > + if (HYPERVISOR_vcpu_op(VCPUOP_register_runstate_memory_area, > > + cpu, &area)) > > + BUG(); > > The original code did: > > - rc = HYPERVISOR_vcpu_op(VCPUOP_register_runstate_memory_area, cpu, > - &area); > - WARN_ON(rc && rc != -ENOSYS); > - > Any reason not to do this? The original x86 code just BUGs out: I took that version over the ia64 version.