linaro-dev February 2012

linaro-dev@lists.linaro.org

150 participants
147 discussions

[PATCH v3 0/2] Device tree support for TWL regulators

by Rajendra Nayak

Re-sending on top of Tero's changes which are already in -next and the one which adds support for twl6030 vdd1/2/3 SMPS [1]. v3 has mainly 2 differences from v2 -1- TWL driver now uses just one table for both dt and non-dt based lookup for driver data. -2- All common regulator nodes for twl4030 and twl6030 are now defined in the twl4030.dtsi and twl6030.dtsi instead of repeating the nodes in all board files, which also means the patch ('arm/dts: twl: Pass regulator data from dt') has a dependency with the series from Benoit which adds the twl4030.dtsi and twl6030.dtsi files[2]. I have tested the patches on omap4panda and omap3beagle boards. [1] http://marc.info/?l=linux-omap&m=133009693905864&w=2 [2] git://git.kernel.org/pub/scm/linux/kernel/git/bcousson/linux-omap-dt.git for_3.4/dt_i2c_twl Rajendra Nayak (2): regulator: twl: adapt twl-regulator driver to dt arm/dts: twl: Pass regulator data from dt .../bindings/regulator/twl-regulator.txt | 66 +++++ arch/arm/boot/dts/omap3-beagle.dts | 6 + arch/arm/boot/dts/twl4030.dtsi | 18 ++ arch/arm/boot/dts/twl6030.dtsi | 60 +++++ drivers/regulator/twl-regulator.c | 259 +++++++++++++------- 5 files changed, 322 insertions(+), 87 deletions(-) create mode 100644 Documentation/devicetree/bindings/regulator/twl-regulator.txt

12 years, 2 months

[RFC PATCH] hrtimers: system-wide and per-task hrtimer slacks

by Dmitry Antipov

This patch proposes a system-wide sysctl-aware default for the high-resolution timer slack value, which may be changed from 0 to HRTIMER_MAX_SLACK nanoseconds. Default system-wide and per-task values are HRTIMER_DEFAULT_SLACK. Per-task value isn't inherited across fork(); instead, newborn task uses system-wide value by default, and newborn thread uses it's group leader value. Signed-off-by: Dmitry Antipov <dmitry.antipov(a)linaro.org> --- Documentation/sysctl/kernel.txt | 8 ++++++++ include/linux/hrtimer.h | 11 +++++++++++ include/linux/init_task.h | 2 +- include/linux/sched.h | 11 ++++++++--- kernel/fork.c | 9 +++++++-- kernel/futex.c | 4 ++-- kernel/hrtimer.c | 10 +++++++--- kernel/sys.c | 8 +++++--- kernel/sysctl.c | 10 ++++++++++ 9 files changed, 59 insertions(+), 14 deletions(-) diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt index 6d78841..83b63ed 100644 --- a/Documentation/sysctl/kernel.txt +++ b/Documentation/sysctl/kernel.txt @@ -606,6 +606,14 @@ can be ORed together: ============================================================== +timer_slack: + +This value can be used to query and set the default slack for +high-resolution timers, in nanoseconds. The default value is 50 +microseconds, and can be changed from 0 nanoseconds to 1 millisecond. + +============================================================== + unknown_nmi_panic: The value in this file affects behavior of handling NMI. When the diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h index fd0dc30..b9da137 100644 --- a/include/linux/hrtimer.h +++ b/include/linux/hrtimer.h @@ -24,6 +24,16 @@ #include <linux/timer.h> #include <linux/timerqueue.h> +/* + * Default system-wide and per-task hrtimer slack, in nanoseconds. + */ +#define HRTIMER_DEFAULT_SLACK 50000 + +/* + * Reasonable limit for hrtimer slack, in nanoseconds. + */ +#define HRTIMER_MAX_SLACK 1000000 + struct hrtimer_clock_base; struct hrtimer_cpu_base; @@ -323,6 +333,7 @@ extern ktime_t ktime_get_monotonic_offset(void); DECLARE_PER_CPU(struct tick_device, tick_cpu_device); +extern int default_timer_slack_ns; /* Exported timer functions: */ diff --git a/include/linux/init_task.h b/include/linux/init_task.h index 9c66b1a..b29be0d 100644 --- a/include/linux/init_task.h +++ b/include/linux/init_task.h @@ -178,7 +178,7 @@ extern struct cred init_cred; .journal_info = NULL, \ .cpu_timers = INIT_CPU_TIMERS(tsk.cpu_timers), \ .pi_lock = __RAW_SPIN_LOCK_UNLOCKED(tsk.pi_lock), \ - .timer_slack_ns = 50000, /* 50 usec default slack */ \ + .timer_slack_ns = HRTIMER_DEFAULT_SLACK, \ .pids = { \ [PIDTYPE_PID] = INIT_PID_LINK(PIDTYPE_PID), \ [PIDTYPE_PGID] = INIT_PID_LINK(PIDTYPE_PGID), \ diff --git a/include/linux/sched.h b/include/linux/sched.h index 7d379a6..aa0a806 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1551,11 +1551,11 @@ struct task_struct { struct latency_record latency_record[LT_SAVECOUNT]; #endif /* - * time slack values; these are used to round up poll() and - * select() etc timeout values. These are in nanoseconds. + * High-resolution timer slack value, in nanoseconds. + * Used to round up poll()/select(), nanosleep, futex + * waiting, etc. timeout values of non-realtime tasks. */ unsigned long timer_slack_ns; - unsigned long default_timer_slack_ns; struct list_head *scm_work_list; #ifdef CONFIG_FUNCTION_GRAPH_TRACER @@ -2628,6 +2628,11 @@ static inline int spin_needbreak(spinlock_t *lock) #endif } +static inline unsigned long task_timer_slack(struct task_struct *tsk) +{ + return rt_task(tsk) ? 0 : tsk->timer_slack_ns; +} + /* * Thread group CPU time accounting. */ diff --git a/kernel/fork.c b/kernel/fork.c index e2cd3e2..0f9a983 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1167,8 +1167,13 @@ static struct task_struct *copy_process(unsigned long clone_flags, #if defined(SPLIT_RSS_COUNTING) memset(&p->rss_stat, 0, sizeof(p->rss_stat)); #endif - - p->default_timer_slack_ns = current->timer_slack_ns; + /* + * New thread inherits the slack from the group + * leader. New process uses system-default slack. + */ + p->timer_slack_ns = (clone_flags & CLONE_THREAD) ? + current->group_leader->timer_slack_ns : + default_timer_slack_ns; task_io_accounting_init(&p->ioac); acct_clear_integrals(p); diff --git a/kernel/futex.c b/kernel/futex.c index 1614be2..a0d302d 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -1887,7 +1887,7 @@ static int futex_wait(u32 __user *uaddr, unsigned int flags, u32 val, HRTIMER_MODE_ABS); hrtimer_init_sleeper(to, current); hrtimer_set_expires_range_ns(&to->timer, *abs_time, - current->timer_slack_ns); + task_timer_slack(current)); } retry: @@ -2281,7 +2281,7 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags, HRTIMER_MODE_ABS); hrtimer_init_sleeper(to, current); hrtimer_set_expires_range_ns(&to->timer, *abs_time, - current->timer_slack_ns); + task_timer_slack(current)); } /* diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index ae34bf5..0c56fec 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -51,6 +51,12 @@ #include <trace/events/timer.h> /* + * Default hrtimer slack value, in nanoseconds. May be changed in + * [0..HRTIMER_MAX_SLACK] range through kernel.timer_slack sysctl. + */ +__read_mostly int default_timer_slack_ns = HRTIMER_DEFAULT_SLACK; + +/* * The timer bases: * * There are more clockids then hrtimer bases. Thus, we index @@ -1564,9 +1570,7 @@ long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp, int ret = 0; unsigned long slack; - slack = current->timer_slack_ns; - if (rt_task(current)) - slack = 0; + slack = task_timer_slack(current); hrtimer_init_on_stack(&t.timer, clockid, mode); hrtimer_set_expires_range_ns(&t.timer, timespec_to_ktime(*rqtp), slack); diff --git a/kernel/sys.c b/kernel/sys.c index 4070153..e976540 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -22,6 +22,7 @@ #include <linux/device.h> #include <linux/key.h> #include <linux/times.h> +#include <linux/hrtimer.h> #include <linux/posix-timers.h> #include <linux/security.h> #include <linux/dcookies.h> @@ -1919,10 +1920,11 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, case PR_SET_TIMERSLACK: if (arg2 <= 0) current->timer_slack_ns = - current->default_timer_slack_ns; - else + default_timer_slack_ns; + else if (arg2 <= HRTIMER_MAX_SLACK) current->timer_slack_ns = arg2; - error = 0; + else + error = -EINVAL; break; case PR_MCE_KILL: if (arg4 | arg5) diff --git a/kernel/sysctl.c b/kernel/sysctl.c index f487f25..2cd42c6 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -136,6 +136,7 @@ static int min_percpu_pagelist_fract = 8; static int ngroups_max = NGROUPS_MAX; static const int cap_last_cap = CAP_LAST_CAP; +static const int slack_max = HRTIMER_MAX_SLACK; #ifdef CONFIG_INOTIFY_USER #include <linux/inotify.h> @@ -1004,6 +1005,15 @@ static struct ctl_table kern_table[] = { .proc_handler = proc_dointvec, }, #endif + { + .procname = "timer_slack", + .data = &default_timer_slack_ns, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = &zero, + .extra2 = &slack_max, + }, { } }; -- 1.7.7.6

12 years, 2 months

Re: [Gumstix-users] try linaro gumstix as accesspoint for wifi?

by Sudhangathan B S

Hello Booher, I was previously using Angstrom Gnome OS given for Gumstix by Sakoman, this turned upto be a nightmare, just as you have told, with adhoc WiFi. I gave up.. I started with Linaro (Ubuntu for embedded systems by Canonical). In Linaro WiFi and bluetooth both work very well including the AdHoc mode in WiFi. In Linaro I haven't figured out how to sense ADC pins, which I was able to do using Angstrom-Gnome. So if you don't require ADC sensing for the moment, you can start with Linaro. Regards, --------------------------------- Sudhangathan BS Ph:(+91) 9731-905-205 ---------------------------------

12 years, 2 months

[PATCH] sched: generalize CONFIG_IRQ_TIME_ACCOUNTING for X86 and ARM

by Dmitry Antipov

Generalize CONFIG_IRQ_TIME_ACCOUNTING between X86 and ARM, move "noirqtime=" option to common debugging code. For a bit of backward compatibility, X86-specific option "tsc=noirqtime" is preserved, but issues a warning. Suggested-by: Yong Zhang <yong.zhang0(a)gmail.com> Suggested-by: Russell King <rmk+kernel(a)arm.linux.org.uk> Suggested-by: Ingo Molnar <mingo(a)elte.hu> Suggested-by: Peter Zijlstra <peterz(a)infradead.org> Acked-by: Venkatesh Pallipadi <venki(a)google.com> Signed-off-by: Dmitry Antipov <dmitry.antipov(a)linaro.org> --- Documentation/kernel-parameters.txt | 9 +++++---- arch/arm/kernel/sched_clock.c | 2 ++ arch/x86/Kconfig | 11 ----------- arch/x86/kernel/tsc.c | 12 ++++++------ include/linux/sched.h | 6 +----- kernel/sched/core.c | 24 +++++++++++++++++++----- lib/Kconfig.debug | 12 ++++++++++++ 7 files changed, 45 insertions(+), 31 deletions(-) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 033d4e6..a5da255 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1790,6 +1790,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted. noirqdebug [X86-32] Disables the code which attempts to detect and disable unhandled interrupt sources. + noirqtime [X86,ARM] Run time disables IRQ_TIME_ACCOUNTING and + eliminates the timestamping on irq/softirq entry/exit. + no_timer_check [X86,APIC] Disables the code which tests for broken timer IRQ sources. @@ -2636,10 +2639,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted. as the stability checks done at bootup. Used to enable high-resolution timer mode on older hardware, and in virtualized environment. - [x86] noirqtime: Do not use TSC to do irq accounting. - Used to run time disable IRQ_TIME_ACCOUNTING on any - platforms where RDTSC is slow and this accounting - can add overhead. + [x86] noirqtime: obsoleted by "noirqtime" generic option, + see it's documentation for details. turbografx.map[2|3]= [HW,JOY] TurboGraFX parallel port interface diff --git a/arch/arm/kernel/sched_clock.c b/arch/arm/kernel/sched_clock.c index 5416c7c..30b5f89 100644 --- a/arch/arm/kernel/sched_clock.c +++ b/arch/arm/kernel/sched_clock.c @@ -144,6 +144,8 @@ void __init setup_sched_clock(u32 (*read)(void), int bits, unsigned long rate) */ cd.epoch_ns = 0; + enable_sched_clock_irqtime(); + pr_debug("Registered %pF as sched_clock source\n", read); } diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 5bed94e..4759676 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -805,17 +805,6 @@ config SCHED_MC making when dealing with multi-core CPU chips at a cost of slightly increased overhead in some places. If unsure say N here. -config IRQ_TIME_ACCOUNTING - bool "Fine granularity task level IRQ time accounting" - default n - ---help--- - Select this option to enable fine granularity task irq time - accounting. This is done by reading a timestamp on each - transitions between softirq and hardirq state, so there can be a - small performance impact. - - If in doubt, say N here. - source "kernel/Kconfig.preempt" config X86_UP_APIC diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c index a62c201..f1b2b63 100644 --- a/arch/x86/kernel/tsc.c +++ b/arch/x86/kernel/tsc.c @@ -103,14 +103,15 @@ int __init notsc_setup(char *str) __setup("notsc", notsc_setup); -static int no_sched_irq_time; - static int __init tsc_setup(char *str) { if (!strcmp(str, "reliable")) tsc_clocksource_reliable = 1; - if (!strncmp(str, "noirqtime", 9)) - no_sched_irq_time = 1; + if (!strncmp(str, "noirqtime", 9)) { + printk(KERN_WARNING "tsc: tsc=noirqtime is " + "obsolete, use noirqtime instead\n"); + disable_sched_clock_irqtime(); + } return 1; } @@ -978,8 +979,7 @@ void __init tsc_init(void) /* now allow native_sched_clock() to use rdtsc */ tsc_disabled = 0; - if (!no_sched_irq_time) - enable_sched_clock_irqtime(); + enable_sched_clock_irqtime(); lpj = ((u64)tsc_khz * 1000); do_div(lpj, HZ); diff --git a/include/linux/sched.h b/include/linux/sched.h index 7d379a6..ea4019c 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1961,11 +1961,7 @@ extern void sched_clock_idle_wakeup_event(u64 delta_ns); #endif #ifdef CONFIG_IRQ_TIME_ACCOUNTING -/* - * An i/f to runtime opt-in for irq time accounting based off of sched_clock. - * The reason for this explicit opt-in is not to have perf penalty with - * slow sched_clocks. - */ +extern int sched_clock_irqtime; extern void enable_sched_clock_irqtime(void); extern void disable_sched_clock_irqtime(void); #else diff --git a/kernel/sched/core.c b/kernel/sched/core.c index b342f57..4693509 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -757,11 +757,17 @@ static DEFINE_PER_CPU(u64, cpu_hardirq_time); static DEFINE_PER_CPU(u64, cpu_softirq_time); static DEFINE_PER_CPU(u64, irq_start_time); -static int sched_clock_irqtime; + +/* + * -1 if not initialized, 0 if disabled with "noirqtime" kernel option + * or after unstable clock was detected, 1 if enabled and active. + */ +__read_mostly int sched_clock_irqtime = -1; void enable_sched_clock_irqtime(void) { - sched_clock_irqtime = 1; + if (sched_clock_irqtime == -1) + sched_clock_irqtime = 1; } void disable_sched_clock_irqtime(void) @@ -769,6 +775,14 @@ void disable_sched_clock_irqtime(void) sched_clock_irqtime = 0; } +static int __init irqtime_setup(char *str) +{ + sched_clock_irqtime = 0; + return 1; +} + +__setup("noirqtime", irqtime_setup); + #ifndef CONFIG_64BIT static DEFINE_PER_CPU(seqcount_t, irq_time_seq); @@ -822,7 +836,7 @@ void account_system_vtime(struct task_struct *curr) s64 delta; int cpu; - if (!sched_clock_irqtime) + if (sched_clock_irqtime < 1) return; local_irq_save(flags); @@ -2852,7 +2866,7 @@ void account_process_tick(struct task_struct *p, int user_tick) cputime_t one_jiffy_scaled = cputime_to_scaled(cputime_one_jiffy); struct rq *rq = this_rq(); - if (sched_clock_irqtime) { + if (sched_clock_irqtime > 0) { irqtime_account_process_tick(p, user_tick, rq); return; } @@ -2886,7 +2900,7 @@ void account_steal_ticks(unsigned long ticks) void account_idle_ticks(unsigned long ticks) { - if (sched_clock_irqtime) { + if (sched_clock_irqtime > 0) { irqtime_account_idle_ticks(ticks); return; } diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 8745ac7..236e814 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -299,6 +299,18 @@ config SCHEDSTATS application, you can say N to avoid the very slight overhead this adds. +config IRQ_TIME_ACCOUNTING + bool "Fine granularity task level IRQ time accounting" + depends on X86 || ARM + default n + ---help--- + Select this option to enable fine granularity task irq time + accounting. This is done by reading a timestamp on each + transitions between softirq and hardirq state, so there can be a + small performance impact. + + If in doubt, say N here. + config TIMER_STATS bool "Collect kernel timers statistics" depends on DEBUG_KERNEL && PROC_FS -- 1.7.7.6

12 years, 2 months

[PATCH] sched: generalize CONFIG_IRQ_TIME_ACCOUNTING for X86 and ARM

by Dmitry Antipov

Generalize CONFIG_IRQ_TIME_ACCOUNTING between X86 and ARM, move "noirqtime=" option to common debugging code. For a bit of backward compatibility, X86-specific option "tsc=noirqtime" is preserved, but issues a warning. Suggested-by: Yong Zhang <yong.zhang0(a)gmail.com> Suggested-by: Russell King <rmk+kernel(a)arm.linux.org.uk> Suggested-by: Ingo Molnar <mingo(a)elte.hu> Acked-by: Venkatesh Pallipadi <venki(a)google.com> Signed-off-by: Dmitry Antipov <dmitry.antipov(a)linaro.org> --- Documentation/kernel-parameters.txt | 9 +++++---- arch/arm/kernel/sched_clock.c | 2 ++ arch/x86/Kconfig | 11 ----------- arch/x86/kernel/tsc.c | 12 ++++++------ include/linux/sched.h | 17 ++++++++++------- kernel/sched/core.c | 21 ++++++++++++--------- lib/Kconfig.debug | 12 ++++++++++++ 7 files changed, 47 insertions(+), 37 deletions(-) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 033d4e6..a5da255 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1790,6 +1790,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted. noirqdebug [X86-32] Disables the code which attempts to detect and disable unhandled interrupt sources. + noirqtime [X86,ARM] Run time disables IRQ_TIME_ACCOUNTING and + eliminates the timestamping on irq/softirq entry/exit. + no_timer_check [X86,APIC] Disables the code which tests for broken timer IRQ sources. @@ -2636,10 +2639,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted. as the stability checks done at bootup. Used to enable high-resolution timer mode on older hardware, and in virtualized environment. - [x86] noirqtime: Do not use TSC to do irq accounting. - Used to run time disable IRQ_TIME_ACCOUNTING on any - platforms where RDTSC is slow and this accounting - can add overhead. + [x86] noirqtime: obsoleted by "noirqtime" generic option, + see it's documentation for details. turbografx.map[2|3]= [HW,JOY] TurboGraFX parallel port interface diff --git a/arch/arm/kernel/sched_clock.c b/arch/arm/kernel/sched_clock.c index 5416c7c..30b5f89 100644 --- a/arch/arm/kernel/sched_clock.c +++ b/arch/arm/kernel/sched_clock.c @@ -144,6 +144,8 @@ void __init setup_sched_clock(u32 (*read)(void), int bits, unsigned long rate) */ cd.epoch_ns = 0; + enable_sched_clock_irqtime(); + pr_debug("Registered %pF as sched_clock source\n", read); } diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 5bed94e..4759676 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -805,17 +805,6 @@ config SCHED_MC making when dealing with multi-core CPU chips at a cost of slightly increased overhead in some places. If unsure say N here. -config IRQ_TIME_ACCOUNTING - bool "Fine granularity task level IRQ time accounting" - default n - ---help--- - Select this option to enable fine granularity task irq time - accounting. This is done by reading a timestamp on each - transitions between softirq and hardirq state, so there can be a - small performance impact. - - If in doubt, say N here. - source "kernel/Kconfig.preempt" config X86_UP_APIC diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c index a62c201..f1b2b63 100644 --- a/arch/x86/kernel/tsc.c +++ b/arch/x86/kernel/tsc.c @@ -103,14 +103,15 @@ int __init notsc_setup(char *str) __setup("notsc", notsc_setup); -static int no_sched_irq_time; - static int __init tsc_setup(char *str) { if (!strcmp(str, "reliable")) tsc_clocksource_reliable = 1; - if (!strncmp(str, "noirqtime", 9)) - no_sched_irq_time = 1; + if (!strncmp(str, "noirqtime", 9)) { + printk(KERN_WARNING "tsc: tsc=noirqtime is " + "obsolete, use noirqtime instead\n"); + disable_sched_clock_irqtime(); + } return 1; } @@ -978,8 +979,7 @@ void __init tsc_init(void) /* now allow native_sched_clock() to use rdtsc */ tsc_disabled = 0; - if (!no_sched_irq_time) - enable_sched_clock_irqtime(); + enable_sched_clock_irqtime(); lpj = ((u64)tsc_khz * 1000); do_div(lpj, HZ); diff --git a/include/linux/sched.h b/include/linux/sched.h index 7d379a6..9b13f79 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1961,13 +1961,16 @@ extern void sched_clock_idle_wakeup_event(u64 delta_ns); #endif #ifdef CONFIG_IRQ_TIME_ACCOUNTING -/* - * An i/f to runtime opt-in for irq time accounting based off of sched_clock. - * The reason for this explicit opt-in is not to have perf penalty with - * slow sched_clocks. - */ -extern void enable_sched_clock_irqtime(void); -extern void disable_sched_clock_irqtime(void); +extern int sched_clock_irqtime; +static inline void enable_sched_clock_irqtime(void) +{ + if (sched_clock_irqtime == -1) + sched_clock_irqtime = 1; +} +static inline void disable_sched_clock_irqtime(void) +{ + sched_clock_irqtime = 0; +} #else static inline void enable_sched_clock_irqtime(void) {} static inline void disable_sched_clock_irqtime(void) {} diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 5255c9d..4e7a197 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -757,18 +757,21 @@ static DEFINE_PER_CPU(u64, cpu_hardirq_time); static DEFINE_PER_CPU(u64, cpu_softirq_time); static DEFINE_PER_CPU(u64, irq_start_time); -static int sched_clock_irqtime; -void enable_sched_clock_irqtime(void) -{ - sched_clock_irqtime = 1; -} +/* + * -1 if not initialized, 0 if disabled with "noirqtime" kernel option + * or after unstable clock was detected, 1 if enabled and active. + */ +__read_mostly int sched_clock_irqtime = -1; -void disable_sched_clock_irqtime(void) +static int __init irqtime_setup(char *str) { sched_clock_irqtime = 0; + return 1; } +__setup("noirqtime", irqtime_setup); + #ifndef CONFIG_64BIT static DEFINE_PER_CPU(seqcount_t, irq_time_seq); @@ -822,7 +825,7 @@ void account_system_vtime(struct task_struct *curr) s64 delta; int cpu; - if (!sched_clock_irqtime) + if (sched_clock_irqtime < 1) return; local_irq_save(flags); @@ -2853,7 +2856,7 @@ void account_process_tick(struct task_struct *p, int user_tick) cputime_t one_jiffy_scaled = cputime_to_scaled(cputime_one_jiffy); struct rq *rq = this_rq(); - if (sched_clock_irqtime) { + if (sched_clock_irqtime > 0) { irqtime_account_process_tick(p, user_tick, rq); return; } @@ -2887,7 +2890,7 @@ void account_steal_ticks(unsigned long ticks) void account_idle_ticks(unsigned long ticks) { - if (sched_clock_irqtime) { + if (sched_clock_irqtime > 0) { irqtime_account_idle_ticks(ticks); return; } diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 8745ac7..236e814 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -299,6 +299,18 @@ config SCHEDSTATS application, you can say N to avoid the very slight overhead this adds. +config IRQ_TIME_ACCOUNTING + bool "Fine granularity task level IRQ time accounting" + depends on X86 || ARM + default n + ---help--- + Select this option to enable fine granularity task irq time + accounting. This is done by reading a timestamp on each + transitions between softirq and hardirq state, so there can be a + small performance impact. + + If in doubt, say N here. + config TIMER_STATS bool "Collect kernel timers statistics" depends on DEBUG_KERNEL && PROC_FS -- 1.7.7.6

12 years, 2 months

is there fence like abstraction for hwmem+cma

by Westermann Fu

Hi, guys: As I know linaro is working on a unified memory manager for soc world like a similar one already exists in PC world (gem/ttm). But I'm curious about how this manager handle the different sync notify between various different IP vendor? As we know, on PC the vsp+capture+graphic+display always done by one unit--the GPU, if a piece of hardware memory buffer wanted to be zero-copied between vsp/graphic/display there must be some sync/notify mechanism otherwise the race condition will occur. On gpu always an interrupt driven object fence can handle it. But in soc, there is no integrated vsp/graphic/display, they all may come from various independent ip vendor, so there may no unified interrupt source can be collected by memory manager to know whether one buffer hasn't be completed by the previous engine and the next engine should block wait but without cpu blocked too. Thanks Regards

12 years, 2 months

anybody willing to boot a test kernel on an omap34xx/omap2 board for me?

by Peter Maydell

Hi; I'm hoping somebody will be willing to run a test kernel for me on some omap boards and send me the dmesg output. (I'm trying to sort out QEMU's modelling of the OMAP ID registers and the TRMs are rather unhelpful; in particular the OMAP35x TRM claims that there are two overlapping registers at addresses 0x218-0x21c!) I've done a Beagle xM which is an OMAP3630, but I'm looking for the results for OMAP34xx/35xx (I think classic Beagle is this) and also if possible an OMAP2 board. The kernel is http://people.linaro.org/~pmaydell/uImage.test (it's the linaro 3.0 kernel with a stock omap2_defconfig and some extra printks so it shouldn't do anything too alarming to your board :-)). It needs the command line arguments 'earlyprintk debug console=ttyO2,115200' (possibly for omap2 the console tty device is different) and I'm interested in the bit of dmesg output near the start: [ 0.000000] PMM: ID register dump: [ 0.000000] register offset 0x204 value 0x0b89102f [ 0.000000] register offset 0x208 value 0x00000000 [ 0.000000] register offset 0x20c value 0x00000000 [ 0.000000] register offset 0x210 value 0x000000f0 [ 0.000000] register offset 0x214 value 0xcafeb891 [ 0.000000] register offset 0x218 value 0x0703201f [ 0.000000] register offset 0x21c value 0x015739ea [ 0.000000] register offset 0x220 value 0x1bf00000 [ 0.000000] register offset 0x224 value 0x5dd40000 [ 0.000000] OMAP3630 ES1.0 (l2cache iva sgx neon isp 192mhz_clk ) (so you don't need the initrd/modules/etc, it's ok if it doesn't boot fully.) Thanks in advance! -- PMM

12 years, 2 months

Improvements to Android Build errors separation (and NOT BUILT status)

by Paul Sokolovsky

Hello, One of the issues with https://android-build.linaro.org/ is that, if build fails, it's not easy to tell if it happened because of compilation error ("real" failure) or due to non-deterministic error with setting up infrastructure for build (e.g. during source checkout). The latter not so uncommon due to vast source size of Android and complexity of cloud infrastructure. This became especially problematic with start of automated CI loop, where it leads to false negatives when doing pre-merge testing. Improving this situation was subject of few blueprints in which Infrastructure team worked, and recently, a solution was deployed. With it, if a build fails due to non-deterministic infrastructure error, it will get status of "NOT BUILT", meaning that a build never actually got to compilation phase. Suggested action in such case is to retry. Please note that Jenkins there is some inconsistency within the Jenkins itself regarding NOT BUILT status - "Pending" is used as a display name in places, and the same gray icon used as for ABORTED builds. So, please keep that in mind, or yet better use Build Frontend. Unfortunately, even short weekend testing showed that error separation achieved is not ideal (folks who participated in Connect Q4.11 session dedicated to this, may remember that I said that it would take adding AI to do that properly ;-) ). In particular, if there was an issue with manifest file (essentially, an error in Android source code), it will be reported as NOT BUILT instead of FAILED. Here's example of such build: https://android-build.linaro.org/jenkins/job/linaro-android_panda-ics-gcc44… Opposite miscategorization may also happen: very early infra error may be reported as FAILED instead of NOT BUILT. Example: https://android-build.linaro.org/jenkins/job/linaro-android_panda-ics-gcc46… So, Infrastructure team will continue to work on improving reliability of builds, but in the meantime please keep looking in the build logs for actual cause of the failure (feel free to report unexpected build status to https://bugs.launchpad.net/linaro-android-infrastructure) -- Best Regards, Paul Linaro.org | Open source software for ARM SoCs Follow Linaro: http://www.facebook.com/pages/Linaro http://twitter.com/#!/linaroorg - http://www.linaro.org/linaro-blog

12 years, 2 months

[PATCH] gic : check if there are pending interrupts

by Daniel Lezcano

The following patch checks if there are pending interrupts on the gic. This function is needed for example for the ux500 cpuidle driver. When the A9 cores and the gic are decoupled from the PRCMU, the idle routine has to check if an interrupt is pending on the gic before entering in retention mode. Signed-off-by: Daniel Lezcano <daniel.lezcano(a)linaro.org> --- arch/arm/common/gic.c | 37 +++++++++++++++++++++++++++++++++++ arch/arm/include/asm/hardware/gic.h | 2 +- 2 files changed, 38 insertions(+), 1 deletions(-) diff --git a/arch/arm/common/gic.c b/arch/arm/common/gic.c index aa52699..2528094 100644 --- a/arch/arm/common/gic.c +++ b/arch/arm/common/gic.c @@ -750,6 +750,43 @@ void gic_raise_softirq(const struct cpumask *mask, unsigned int irq) } #endif +/* + * gic_pending_irq - checks if there are pending interrupts on the gic + * + * Disabling an interrupt only disables the forwarding of the + * interrupt to any CPU interface. It does not prevent the interrupt + * from changing state, for example becoming pending, or active and + * pending if it is already active. For this reason, we have to check + * the interrupt is pending *and* is enabled. + * + * Returns true if there are pending and enabled interrupts, false + * otherwise. + */ +bool gic_pending_irq(unsigned int gic_nr) +{ + u32 pr; /* Pending register */ + u32 er; /* Enable register */ + void __iomem *dist_base; + int gic_irqs; + int i; + + BUG_ON(gic_nr >= MAX_GIC_NR); + + gic_irqs = gic_data[gic_nr].gic_irqs; + dist_base = gic_data_dist_base(&gic_data[gic_nr]); + + for (i = 0; i < DIV_ROUND_UP(gic_irqs, 32); i++) { + + pr = readl_relaxed(dist_base + GIC_DIST_PENDING_SET + i * 4); + er = readl_relaxed(dist_base + GIC_DIST_ENABLE_SET + i * 4); + + if (pr & er) + return true; + } + + return false; +} + #ifdef CONFIG_OF static int gic_cnt __initdata = 0; diff --git a/arch/arm/include/asm/hardware/gic.h b/arch/arm/include/asm/hardware/gic.h index 4b1ce6c..d198ac0 100644 --- a/arch/arm/include/asm/hardware/gic.h +++ b/arch/arm/include/asm/hardware/gic.h @@ -45,7 +45,7 @@ void gic_secondary_init(unsigned int); void gic_handle_irq(struct pt_regs *regs); void gic_cascade_irq(unsigned int gic_nr, unsigned int irq); void gic_raise_softirq(const struct cpumask *mask, unsigned int irq); - +bool gic_pending_irq(unsigned int gic_nr); static inline void gic_init(unsigned int nr, int start, void __iomem *dist , void __iomem *cpu) { -- 1.7.5.4

12 years, 2 months

Linaro Release 12.02 Postmortem Summary

by David Zinman

Postmortem and lessons learned for Linaro's release 2012.02 https://wiki.linaro.org/Cycles/1202/Release/Review Highlights and Key Successes ============================ By using proper image builds and validation with LAVA the Linaro Developer Platform can ensure all images are properly tested as soon they are published. A new proposal for the linux-linaro tree was introduced which will make the linux-linaro tree the single reference for kernel work at Linaro and should always be working against latest upstream RC release. The Linaro Developer Platform team will now be responsible for packaging and maintenance of all the LT kernel flavours. Responsibilities will include validating the kernel daily with LAVA, and only publishing the kernels (which pass validation testing) to be used by the LEB images (until the new linux-linaro tree is in place). During February 6-10 Linaro hosted Linaro Connect Q1.12. Rounding out the event were daily plenary, planning, and hacking sessions which attendees were encouraged to attend and take part in. This event was the largest Linaro Connect to date and was highlighted by the participation of community members and other external attendees, notably from Google. The event also hosted "Demo Friday" where once again the public was invited to participate in hands-on demonstrations of Linaro developments. Some demos can be seen on Linaro's Youtube channel: Ubuntu TV Demo on ARM http://www.youtube.com/watch?v=tpIFaAxyFGE&list=UUAl2MfCBjH5y0nIym0ujHf… XBMC on ST-ERICSSON's Snowball http://www.youtube.com/watch?v=14p-WOFAWWw&list=UUAl2MfCBjH5y0nIym0ujHf… Linaro was also well represented at Embedded Linux Conference with a very high percentage of presentations given by Linaro team member or seconders. For links to highlights from Linaro Connect and ELC please go to the bottom of this announcement. Postmortem and Lessons Learned ============================== This cycle was the shortest that Linaro release has encountered, and this presented some challenges. The small number of development and planning days, along with interruptions by Linaro Connect, ELC and ABS contributed to a smaller production of deliverables from the team. There was a loss of focus as people dealt with fractured development cycle, jet lag and the shorter work sprint. A solution discussed to mitigate this problem is that for short cycles, a different type of planning should be applied that is focused more on bug-fixing and the backlog, rather than larger ambitious deliverables. The Android team has been doing a large amount of kernel development and has suggested the addition of some sort of kernel resources for iMX53, Origen and, possibly Snowball. Links ===== -= Highlights from this Linaro Connect =- Plenary Sessions: David Rusling, Linaro CTO, Phase III Plenary Presentation at Linaro Connect Q1.12 http://www.youtube.com/watch?v=ZSoCCRF7Hl0&list=UUAl2MfCBjH5y0nIym0ujHf… George Grey, Linaro CEO, Plenary Presentation at Linaro Connect Q1.12 http://www.youtube.com/watch?v=Cl4Yr9rf7fQ&list=UUAl2MfCBjH5y0nIym0ujHf… Kiko, Linaro Engineering VP: ARM, the new mainstream http://www.youtube.com/watch?v=86Ox3wWOWTw&list=UUAl2MfCBjH5y0nIym0ujHf… Linaro Connect Plenary: Andrea Gallo of ST-ERICSSON http://www.youtube.com/watch?v=-WnsPPq_A50&list=UUAl2MfCBjH5y0nIym0ujHf… Tim Bird of the Linux Foundation at Linaro Connect http://www.youtube.com/watch?v=dub3HgezCAs&list=UUAl2MfCBjH5y0nIym0ujHf… Interviews: Linaro Connect: Patrik Klinger Talks Snowball & The Igloo Community http://www.youtube.com/watch?v=cxYdyEEb9X4&list=UUAl2MfCBjH5y0nIym0ujHf… Tim Bird and David Rusling Chat at Linaro Connect http://www.youtube.com/watch?v=xgdTzBl-3wQ&list=UUAl2MfCBjH5y0nIym0ujHf… -= Highlights from ELC =- http://video.linux.com/videos/ubuntu-on-arm-improvements-and-optimizations-… http://video.linux.com/videos/dma-buffer-sharing-an-introduction http://www.cnx-software.com/2012/02/25/binary_blobs_attack-elc-2012/ http://video.linux.com/videos/what-android-and-embedded-linux-can-learn-fro… For these and other presentations from ELC please visit http://video.linux.com/categories/2012-embedded-linux-conference -- David Zinman Linaro Release Manager | Project Manager Linaro.org | Open source software for ARM SoCs

12 years, 2 months

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linaro-dev February 2012