From: "Gautham R. Shenoy" <ego@linux.vnet.ibm.com> To: Nathan Lynch <nathanl@linux.ibm.com>, Michael Ellerman <mpe@ellerman.id.au>, Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>, Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>, "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>, Tyrel Datwyler <tyreld@linux.ibm.com> Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, "Gautham R. Shenoy" <ego@linux.vnet.ibm.com> Subject: [PATCH v4 3/6] powerpc/pseries: Account for SPURR ticks on idle CPUs Date: Fri, 27 Mar 2020 17:02:37 +0530 [thread overview] Message-ID: <1585308760-28792-4-git-send-email-ego@linux.vnet.ibm.com> (raw) In-Reply-To: <1585308760-28792-1-git-send-email-ego@linux.vnet.ibm.com> From: "Gautham R. Shenoy" <ego@linux.vnet.ibm.com> On Pseries LPARs, to calculate utilization, we need to know the [S]PURR ticks when the CPUs were busy or idle. Via pseries_idle_prolog(), pseries_idle_epilog(), we track the idle PURR ticks in the VPA variable "wait_state_cycles". This patch extends the support to account for the idle SPURR ticks. It also provides an accessor function to accurately reads idle SPURR ticks. Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> --- arch/powerpc/include/asm/idle.h | 33 +++++++++++++++++++++++++++++++++ arch/powerpc/platforms/pseries/setup.c | 2 ++ 2 files changed, 35 insertions(+) diff --git a/arch/powerpc/include/asm/idle.h b/arch/powerpc/include/asm/idle.h index d4bfb6a..accd1f5 100644 --- a/arch/powerpc/include/asm/idle.h +++ b/arch/powerpc/include/asm/idle.h @@ -5,13 +5,20 @@ #include <asm/paca.h> #ifdef CONFIG_PPC_PSERIES +DECLARE_PER_CPU(u64, idle_spurr_cycles); DECLARE_PER_CPU(u64, idle_entry_purr_snap); +DECLARE_PER_CPU(u64, idle_entry_spurr_snap); static inline void snapshot_purr_idle_entry(void) { *this_cpu_ptr(&idle_entry_purr_snap) = mfspr(SPRN_PURR); } +static inline void snapshot_spurr_idle_entry(void) +{ + *this_cpu_ptr(&idle_entry_spurr_snap) = mfspr(SPRN_SPURR); +} + static inline void update_idle_purr_accounting(void) { u64 wait_cycles; @@ -22,10 +29,19 @@ static inline void update_idle_purr_accounting(void) get_lppaca()->wait_state_cycles = cpu_to_be64(wait_cycles); } +static inline void update_idle_spurr_accounting(void) +{ + u64 *idle_spurr_cycles_ptr = this_cpu_ptr(&idle_spurr_cycles); + u64 in_spurr = *this_cpu_ptr(&idle_entry_spurr_snap); + + *idle_spurr_cycles_ptr += mfspr(SPRN_SPURR) - in_spurr; +} + static inline void pseries_idle_prolog(void) { ppc64_runlatch_off(); snapshot_purr_idle_entry(); + snapshot_spurr_idle_entry(); /* * Indicate to the HV that we are idle. Now would be * a good time to find other work to dispatch. @@ -36,6 +52,7 @@ static inline void pseries_idle_prolog(void) static inline void pseries_idle_epilog(void) { update_idle_purr_accounting(); + update_idle_spurr_accounting(); get_lppaca()->idle = 0; ppc64_runlatch_on(); } @@ -56,5 +73,21 @@ static inline u64 read_this_idle_purr(void) return be64_to_cpu(get_lppaca()->wait_state_cycles); } +static inline u64 read_this_idle_spurr(void) +{ + /* + * If we are reading from an idle context, update the + * idle-spurr cycles corresponding to the last idle period. + * Since the idle context is not yet over, take a fresh + * snapshot of the idle-spurr. + */ + if (get_lppaca()->idle == 1) { + update_idle_spurr_accounting(); + snapshot_spurr_idle_entry(); + } + + return *this_cpu_ptr(&idle_spurr_cycles); +} + #endif /* CONFIG_PPC_PSERIES */ #endif diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c index 4905c96..1b55e80 100644 --- a/arch/powerpc/platforms/pseries/setup.c +++ b/arch/powerpc/platforms/pseries/setup.c @@ -318,7 +318,9 @@ static int alloc_dispatch_log_kmem_cache(void) } machine_early_initcall(pseries, alloc_dispatch_log_kmem_cache); +DEFINE_PER_CPU(u64, idle_spurr_cycles); DEFINE_PER_CPU(u64, idle_entry_purr_snap); +DEFINE_PER_CPU(u64, idle_entry_spurr_snap); static void pseries_lpar_idle(void) { /* -- 1.9.4
next prev parent reply other threads:[~2020-03-27 11:33 UTC|newest] Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-03-27 11:32 [PATCH v4 0/6] [PATCH v4 0/6] Track and expose idle PURR and SPURR ticks Gautham R. Shenoy 2020-03-27 11:32 ` [PATCH v4 1/6] powerpc: Move idle_loop_prolog()/epilog() functions to header file Gautham R. Shenoy 2020-03-27 11:32 ` [PATCH v4 2/6] powerpc/idle: Add accessor function to always read latest idle PURR Gautham R. Shenoy 2020-04-01 9:42 ` Naveen N. Rao 2020-04-03 6:15 ` Gautham R Shenoy 2020-04-03 10:34 ` Naveen N. Rao 2020-04-03 11:24 ` Gautham R Shenoy 2020-03-27 11:32 ` Gautham R. Shenoy [this message] 2020-03-27 11:32 ` [PATCH v4 4/6] powerpc/sysfs: Show idle_purr and idle_spurr for every CPU Gautham R. Shenoy 2020-03-27 11:32 ` [PATCH v4 5/6] Documentation: Document sysfs interfaces purr, spurr, idle_purr, idle_spurr Gautham R. Shenoy 2020-04-01 9:45 ` Naveen N. Rao 2020-03-27 11:32 ` [PATCH v4 6/6] pseries/sysfs: Minimise IPI noise while reading [idle_][s]purr Gautham R. Shenoy 2020-04-01 9:58 ` Naveen N. Rao 2020-04-01 12:01 ` Gautham R Shenoy 2020-04-02 7:34 ` Naveen N. Rao 2020-04-03 6:28 ` Gautham R Shenoy 2020-04-03 18:10 ` Nathan Lynch
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