From: Santosh Shilimkar <santosh.shilimkar@ti.com> To: linux-arm-kernel@lists.infradead.org Cc: linux-omap@vger.kernel.org, ccross@android.com, catalin.marinas@arm.com, linux@arm.linux.org.uk, linus.ml.walleij@gmail.com, Santosh Shilimkar <santosh.shilimkar@ti.com>, Russell King <rmk+kernel@arm.linux.org.uk> Subject: [PATCH 5/5] ARM: smp: Skip secondary cpu calibration to speed-up boot Date: Mon, 24 Jan 2011 14:21:19 +0530 [thread overview] Message-ID: <1295859080-15259-6-git-send-email-santosh.shilimkar@ti.com> (raw) In-Reply-To: <1295859080-15259-1-git-send-email-santosh.shilimkar@ti.com> On some architectures, secondary cores shares clock with primiary core and hence scale together. Hence secondary core lpj calibration is not necessary and can be skipped to save considerable time. This can speed up the secondary cpu boot and hotplug cpu online paths. The patch is still under discussion and relevant thread is here. http://www.mail-archive.com/linux-omap@vger.kernel.org/msg42902.html Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Cc: Russell King <rmk+kernel@arm.linux.org.uk> --- arch/arm/include/asm/smp.h | 8 ++++++++ arch/arm/kernel/smp.c | 35 ++++++++++++++++++++++++++--------- arch/arm/mach-omap2/omap-smp.c | 3 +++ 3 files changed, 37 insertions(+), 9 deletions(-) diff --git a/arch/arm/include/asm/smp.h b/arch/arm/include/asm/smp.h index 96ed521..150d202 100644 --- a/arch/arm/include/asm/smp.h +++ b/arch/arm/include/asm/smp.h @@ -69,6 +69,14 @@ asmlinkage void secondary_start_kernel(void); extern void platform_secondary_init(unsigned int cpu); /* + * Skip the secondary calibration on architectures sharing clock + * with primary cpu. Needs to be called for archs inside + * platform_secondary_init() + */ +extern void secondary_skip_calibrate(void); + + +/* * Initialize cpu_possible map, and enable coherency */ extern void platform_smp_prepare_cpus(unsigned int); diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index 4539ebc..6aa99bc 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -55,6 +55,8 @@ enum ipi_msg_type { IPI_CPU_STOP, }; +static unsigned int skip_secondary_calibrate; + int __cpuinit __cpu_up(unsigned int cpu) { struct cpuinfo_arm *ci = &per_cpu(cpu_data, cpu); @@ -270,6 +272,16 @@ static void __cpuinit smp_store_cpu_info(unsigned int cpuid) } /* + * Skip the secondary calibration on architectures sharing clock + * with primary cpu. Needs to be called for archs from + * platform_secondary_init() + */ +void secondary_skip_calibrate(void) +{ + skip_secondary_calibrate = 1; +} + +/* * This is the secondary CPU boot entry. We're using this CPUs * idle thread stack, but a set of temporary page tables. */ @@ -312,7 +324,8 @@ asmlinkage void __cpuinit secondary_start_kernel(void) */ percpu_timer_setup(); - calibrate_delay(); + if (!skip_secondary_calibrate) + calibrate_delay(); smp_store_cpu_info(cpu); @@ -330,16 +343,20 @@ asmlinkage void __cpuinit secondary_start_kernel(void) void __init smp_cpus_done(unsigned int max_cpus) { int cpu; - unsigned long bogosum = 0; + char bogosum[32]; + unsigned long bogosums = 0; + + if (!skip_secondary_calibrate) { + for_each_online_cpu(cpu) + bogosums += per_cpu(cpu_data, cpu).loops_per_jiffy; - for_each_online_cpu(cpu) - bogosum += per_cpu(cpu_data, cpu).loops_per_jiffy; + snprintf(bogosum, sizeof(bogosums), " (%lu.%02lu BogoMIPS).\n", + bogosums / (500000/HZ), (bogosums / (5000/HZ)) % 100); + } else + bogosum[0] = '\0'; - printk(KERN_INFO "SMP: Total of %d processors activated " - "(%lu.%02lu BogoMIPS).\n", - num_online_cpus(), - bogosum / (500000/HZ), - (bogosum / (5000/HZ)) % 100); + pr_info("SMP: Total of %d processors activated%s.\n", + num_online_cpus(), bogosum); } void __init smp_prepare_boot_cpu(void) diff --git a/arch/arm/mach-omap2/omap-smp.c b/arch/arm/mach-omap2/omap-smp.c index b66cfe8..7342cd5 100644 --- a/arch/arm/mach-omap2/omap-smp.c +++ b/arch/arm/mach-omap2/omap-smp.c @@ -39,6 +39,9 @@ void __cpuinit platform_secondary_init(unsigned int cpu) */ gic_secondary_init(0); + /* Allow to skip secondary CPU calibration */ + secondary_skip_calibrate(); + /* * Synchronise with the boot thread. */ -- 1.6.0.4
WARNING: multiple messages have this Message-ID (diff)
From: santosh.shilimkar@ti.com (Santosh Shilimkar) To: linux-arm-kernel@lists.infradead.org Subject: [PATCH 5/5] ARM: smp: Skip secondary cpu calibration to speed-up boot Date: Mon, 24 Jan 2011 14:21:19 +0530 [thread overview] Message-ID: <1295859080-15259-6-git-send-email-santosh.shilimkar@ti.com> (raw) In-Reply-To: <1295859080-15259-1-git-send-email-santosh.shilimkar@ti.com> On some architectures, secondary cores shares clock with primiary core and hence scale together. Hence secondary core lpj calibration is not necessary and can be skipped to save considerable time. This can speed up the secondary cpu boot and hotplug cpu online paths. The patch is still under discussion and relevant thread is here. http://www.mail-archive.com/linux-omap at vger.kernel.org/msg42902.html Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Cc: Russell King <rmk+kernel@arm.linux.org.uk> --- arch/arm/include/asm/smp.h | 8 ++++++++ arch/arm/kernel/smp.c | 35 ++++++++++++++++++++++++++--------- arch/arm/mach-omap2/omap-smp.c | 3 +++ 3 files changed, 37 insertions(+), 9 deletions(-) diff --git a/arch/arm/include/asm/smp.h b/arch/arm/include/asm/smp.h index 96ed521..150d202 100644 --- a/arch/arm/include/asm/smp.h +++ b/arch/arm/include/asm/smp.h @@ -69,6 +69,14 @@ asmlinkage void secondary_start_kernel(void); extern void platform_secondary_init(unsigned int cpu); /* + * Skip the secondary calibration on architectures sharing clock + * with primary cpu. Needs to be called for archs inside + * platform_secondary_init() + */ +extern void secondary_skip_calibrate(void); + + +/* * Initialize cpu_possible map, and enable coherency */ extern void platform_smp_prepare_cpus(unsigned int); diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index 4539ebc..6aa99bc 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -55,6 +55,8 @@ enum ipi_msg_type { IPI_CPU_STOP, }; +static unsigned int skip_secondary_calibrate; + int __cpuinit __cpu_up(unsigned int cpu) { struct cpuinfo_arm *ci = &per_cpu(cpu_data, cpu); @@ -270,6 +272,16 @@ static void __cpuinit smp_store_cpu_info(unsigned int cpuid) } /* + * Skip the secondary calibration on architectures sharing clock + * with primary cpu. Needs to be called for archs from + * platform_secondary_init() + */ +void secondary_skip_calibrate(void) +{ + skip_secondary_calibrate = 1; +} + +/* * This is the secondary CPU boot entry. We're using this CPUs * idle thread stack, but a set of temporary page tables. */ @@ -312,7 +324,8 @@ asmlinkage void __cpuinit secondary_start_kernel(void) */ percpu_timer_setup(); - calibrate_delay(); + if (!skip_secondary_calibrate) + calibrate_delay(); smp_store_cpu_info(cpu); @@ -330,16 +343,20 @@ asmlinkage void __cpuinit secondary_start_kernel(void) void __init smp_cpus_done(unsigned int max_cpus) { int cpu; - unsigned long bogosum = 0; + char bogosum[32]; + unsigned long bogosums = 0; + + if (!skip_secondary_calibrate) { + for_each_online_cpu(cpu) + bogosums += per_cpu(cpu_data, cpu).loops_per_jiffy; - for_each_online_cpu(cpu) - bogosum += per_cpu(cpu_data, cpu).loops_per_jiffy; + snprintf(bogosum, sizeof(bogosums), " (%lu.%02lu BogoMIPS).\n", + bogosums / (500000/HZ), (bogosums / (5000/HZ)) % 100); + } else + bogosum[0] = '\0'; - printk(KERN_INFO "SMP: Total of %d processors activated " - "(%lu.%02lu BogoMIPS).\n", - num_online_cpus(), - bogosum / (500000/HZ), - (bogosum / (5000/HZ)) % 100); + pr_info("SMP: Total of %d processors activated%s.\n", + num_online_cpus(), bogosum); } void __init smp_prepare_boot_cpu(void) diff --git a/arch/arm/mach-omap2/omap-smp.c b/arch/arm/mach-omap2/omap-smp.c index b66cfe8..7342cd5 100644 --- a/arch/arm/mach-omap2/omap-smp.c +++ b/arch/arm/mach-omap2/omap-smp.c @@ -39,6 +39,9 @@ void __cpuinit platform_secondary_init(unsigned int cpu) */ gic_secondary_init(0); + /* Allow to skip secondary CPU calibration */ + secondary_skip_calibrate(); + /* * Synchronise with the boot thread. */ -- 1.6.0.4
next prev parent reply other threads:[~2011-01-24 8:51 UTC|newest] Thread overview: 132+ messages / expand[flat|nested] mbox.gz Atom feed top 2011-01-24 8:51 [PATCH 0/5] ARM: Few patches for PM enablement Santosh Shilimkar 2011-01-24 8:51 ` Santosh Shilimkar 2011-01-24 8:51 ` [PATCH 1/5] ARM: gic: Add hooks for architecture specific extensions Santosh Shilimkar 2011-01-24 8:51 ` Santosh Shilimkar 2011-01-25 3:03 ` Colin Cross 2011-01-25 3:03 ` Colin Cross 2011-01-25 20:54 ` Colin Cross 2011-01-25 20:54 ` Colin Cross 2011-01-26 7:22 ` Santosh Shilimkar 2011-01-26 7:22 ` Santosh Shilimkar 2011-01-26 7:23 ` Colin Cross 2011-01-26 7:23 ` Colin Cross 2011-01-26 7:31 ` Santosh Shilimkar 2011-01-26 7:31 ` Santosh Shilimkar 2011-01-26 7:52 ` Colin Cross 2011-01-26 7:52 ` Colin Cross 2011-01-26 7:55 ` Santosh Shilimkar 2011-01-26 7:55 ` Santosh Shilimkar 2011-01-24 8:51 ` [PATCH 2/5] ARM: gic: Add distributor and interface enable/disable accessory api Santosh Shilimkar 2011-01-24 8:51 ` Santosh Shilimkar 2011-03-01 5:58 ` Santosh Shilimkar 2011-03-01 5:58 ` Santosh Shilimkar 2011-01-24 8:51 ` [PATCH 3/5] ARM: twd: Add context save restore support Santosh Shilimkar 2011-01-24 8:51 ` Santosh Shilimkar 2011-01-24 11:06 ` Russell King - ARM Linux 2011-01-24 11:06 ` Russell King - ARM Linux 2011-01-24 11:11 ` Russell King - ARM Linux 2011-01-24 11:11 ` Russell King - ARM Linux 2011-01-24 11:16 ` Santosh Shilimkar 2011-01-24 11:16 ` Santosh Shilimkar 2011-01-25 7:39 ` Colin Cross 2011-01-25 7:39 ` Colin Cross 2011-01-25 10:32 ` Russell King - ARM Linux 2011-01-25 10:32 ` Russell King - ARM Linux 2011-01-25 13:23 ` Thomas Gleixner 2011-01-25 13:23 ` Thomas Gleixner 2011-01-25 13:37 ` Russell King - ARM Linux 2011-01-25 13:37 ` Russell King - ARM Linux 2011-01-25 13:55 ` Santosh Shilimkar 2011-01-25 13:55 ` Santosh Shilimkar 2011-01-25 14:12 ` Thomas Gleixner 2011-01-25 14:12 ` Thomas Gleixner 2011-01-25 14:15 ` Russell King - ARM Linux 2011-01-25 14:15 ` Russell King - ARM Linux 2011-01-25 14:24 ` Thomas Gleixner 2011-01-25 14:24 ` Thomas Gleixner 2011-01-25 16:04 ` Santosh Shilimkar 2011-01-25 16:04 ` Santosh Shilimkar 2011-01-25 16:13 ` Russell King - ARM Linux 2011-01-25 16:13 ` Russell King - ARM Linux 2011-01-25 16:14 ` Santosh Shilimkar 2011-01-25 16:14 ` Santosh Shilimkar 2011-01-25 11:29 ` Russell King - ARM Linux 2011-01-25 11:29 ` Russell King - ARM Linux 2011-01-25 11:40 ` Santosh Shilimkar 2011-01-25 11:40 ` Santosh Shilimkar 2011-01-25 11:48 ` Russell King - ARM Linux 2011-01-25 11:48 ` Russell King - ARM Linux 2011-01-25 12:08 ` Santosh Shilimkar 2011-01-25 12:08 ` Santosh Shilimkar 2011-01-25 12:17 ` Russell King - ARM Linux 2011-01-25 12:17 ` Russell King - ARM Linux 2011-01-25 12:20 ` Santosh Shilimkar 2011-01-25 12:20 ` Santosh Shilimkar 2011-01-25 18:44 ` Colin Cross 2011-01-25 18:44 ` Colin Cross 2011-01-24 11:14 ` Santosh Shilimkar 2011-01-24 11:14 ` Santosh Shilimkar 2011-01-24 8:51 ` [PATCH 4/5] ARM: scu: Move register defines to header file Santosh Shilimkar 2011-01-24 8:51 ` Santosh Shilimkar 2011-01-25 11:46 ` Russell King - ARM Linux 2011-01-25 11:46 ` Russell King - ARM Linux 2011-01-25 12:02 ` Santosh Shilimkar 2011-01-25 12:02 ` Santosh Shilimkar 2011-01-25 12:16 ` Russell King - ARM Linux 2011-01-25 12:16 ` Russell King - ARM Linux 2011-01-25 12:29 ` Russell King - ARM Linux 2011-01-25 12:29 ` Russell King - ARM Linux 2011-01-25 12:39 ` Santosh Shilimkar 2011-01-25 12:39 ` Santosh Shilimkar 2011-01-25 12:36 ` Santosh Shilimkar 2011-01-25 12:36 ` Santosh Shilimkar 2011-01-25 12:56 ` Russell King - ARM Linux 2011-01-25 12:56 ` Russell King - ARM Linux 2011-01-25 13:04 ` Russell King - ARM Linux 2011-01-25 13:04 ` Russell King - ARM Linux 2011-01-25 13:06 ` Russell King - ARM Linux 2011-01-25 13:06 ` Russell King - ARM Linux 2011-01-25 18:23 ` Santosh Shilimkar 2011-01-25 18:23 ` Santosh Shilimkar 2011-02-04 10:41 ` Russell King - ARM Linux 2011-02-04 10:41 ` Russell King - ARM Linux 2011-02-04 10:46 ` Santosh Shilimkar 2011-02-04 10:46 ` Santosh Shilimkar 2011-02-04 11:30 ` Russell King - ARM Linux 2011-02-04 11:30 ` Russell King - ARM Linux 2011-02-04 11:34 ` Santosh Shilimkar 2011-02-04 11:34 ` Santosh Shilimkar 2011-02-07 9:51 ` Santosh Shilimkar 2011-02-07 9:51 ` Santosh Shilimkar 2011-02-07 10:18 ` Russell King - ARM Linux 2011-02-07 10:18 ` Russell King - ARM Linux 2011-02-07 10:21 ` Santosh Shilimkar 2011-02-07 10:21 ` Santosh Shilimkar 2011-02-07 10:23 ` Russell King - ARM Linux 2011-02-07 10:23 ` Russell King - ARM Linux 2011-02-07 10:30 ` Santosh Shilimkar 2011-02-07 10:30 ` Santosh Shilimkar 2011-02-10 14:49 ` Santosh Shilimkar 2011-02-10 14:49 ` Santosh Shilimkar 2011-02-10 16:13 ` Russell King - ARM Linux 2011-02-10 16:13 ` Russell King - ARM Linux 2011-02-10 16:26 ` Santosh Shilimkar 2011-02-10 16:26 ` Santosh Shilimkar 2011-01-25 13:05 ` Santosh Shilimkar 2011-01-25 13:05 ` Santosh Shilimkar 2011-01-25 13:41 ` Russell King - ARM Linux 2011-01-25 13:41 ` Russell King - ARM Linux 2011-01-25 13:47 ` Santosh Shilimkar 2011-01-25 13:47 ` Santosh Shilimkar 2011-01-24 8:51 ` Santosh Shilimkar [this message] 2011-01-24 8:51 ` [PATCH 5/5] ARM: smp: Skip secondary cpu calibration to speed-up boot Santosh Shilimkar 2011-01-24 10:30 ` Russell King - ARM Linux 2011-01-24 10:30 ` Russell King - ARM Linux 2011-01-24 8:51 ` Santosh Shilimkar 2011-01-24 8:51 ` Santosh Shilimkar 2011-01-24 8:55 ` Santosh Shilimkar 2011-01-24 8:55 ` Santosh Shilimkar 2011-02-04 10:19 ` [PATCH 0/5] ARM: Few patches for PM enablement Santosh Shilimkar 2011-02-04 10:19 ` Santosh Shilimkar 2011-02-11 14:24 ` Santosh Shilimkar 2011-02-11 14:24 ` Santosh Shilimkar
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