Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964995Ab3E1SP4 (ORCPT ); Tue, 28 May 2013 14:15:56 -0400 Received: from aserp1040.oracle.com ([141.146.126.69]:33113 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964914Ab3E1SPz (ORCPT ); Tue, 28 May 2013 14:15:55 -0400 Date: Tue, 28 May 2013 14:15:15 -0400 From: Konrad Rzeszutek Wilk To: Stefano Stabellini Cc: 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 Subject: Re: [PATCH v4 1/4] xen: move xen_setup_runstate_info and get_runstate_snapshot to drivers/xen/time.c Message-ID: <20130528181515.GB27718@phenom.dumpdata.com> References: <1369763672-12919-1-git-send-email-stefano.stabellini@eu.citrix.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1369763672-12919-1-git-send-email-stefano.stabellini@eu.citrix.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-Source-IP: acsinet21.oracle.com [141.146.126.237] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 9985 Lines: 351 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. > --- > 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? > +} > + > diff --git a/include/xen/xen-ops.h b/include/xen/xen-ops.h > index d6fe062..4fd4e47 100644 > --- a/include/xen/xen-ops.h > +++ b/include/xen/xen-ops.h > @@ -3,6 +3,7 @@ > > #include > #include > +#include > > DECLARE_PER_CPU(struct vcpu_info *, xen_vcpu); > > @@ -16,6 +17,10 @@ void xen_mm_unpin_all(void); > void xen_timer_resume(void); > void xen_arch_resume(void); > > +bool xen_vcpu_stolen(int vcpu); > +void xen_setup_runstate_info(int cpu); > +void xen_get_runstate_snapshot(struct vcpu_runstate_info *res); > + > int xen_setup_shutdown_event(void); > > extern unsigned long *xen_contiguous_bitmap; > -- > 1.7.2.5 > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/