linaro-dev

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4332 discussions

Organizing series and milestones based on quarters

by Zach Pfeffer

All, I recently reorganized my series and milestones to reflect quarters: https://launchpad.net/linaro-android I also filed milestones for the connects so that I can easily find the sessions I had. Thought others may find this useful. -- Zach Pfeffer Android Platform Team Lead, Linaro Platform Teams 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

13 years, 4 months

[PATCH 1/2] vmalloc: use ZERO_SIZE_PTR / ZERO_OR_NULL_PTR

by Dmitry Antipov

- Fix vmap() to return ZERO_SIZE_PTR if 0 pages are requested; - fix __vmalloc_node_range() to return ZERO_SIZE_PTR if 0 bytes are requested; - fix __vunmap() to check passed pointer with ZERO_OR_NULL_PTR. Signed-off-by: Dmitry Antipov <dmitry.antipov(a)linaro.org> --- mm/vmalloc.c | 10 +++++++--- 1 files changed, 7 insertions(+), 3 deletions(-) diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 86ce9a5..040a9cd 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -1456,7 +1456,7 @@ static void __vunmap(const void *addr, int deallocate_pages) { struct vm_struct *area; - if (!addr) + if (unlikely(ZERO_OR_NULL_PTR(addr))) return; if ((PAGE_SIZE-1) & (unsigned long)addr) { @@ -1548,7 +1548,9 @@ void *vmap(struct page **pages, unsigned int count, might_sleep(); - if (count > totalram_pages) + if (unlikely(!count)) + return ZERO_SIZE_PTR; + if (unlikely(count > totalram_pages)) return NULL; area = get_vm_area_caller((count << PAGE_SHIFT), flags, @@ -1648,8 +1650,10 @@ void *__vmalloc_node_range(unsigned long size, unsigned long align, void *addr; unsigned long real_size = size; + if (unlikely(!size)) + return ZERO_SIZE_PTR; size = PAGE_ALIGN(size); - if (!size || (size >> PAGE_SHIFT) > totalram_pages) + if (unlikely((size >> PAGE_SHIFT) > totalram_pages)) goto fail; area = __get_vm_area_node(size, align, VM_ALLOC | VM_UNLIST, -- 1.7.7.6

13 years, 4 months

Benchmark summary for Linaro GCC

by Michael Hope

The topic of benchmarking keeps coming up. We're working on making the next FSF release better, but it's a good idea to track how the current Linaro GCC stacks up against other releases. The summary is at: https://wiki.linaro.org/Internal/ToolChain/Now Included is how our current 4.6 release does against FSF 4.6, the change over six months, and how the upcoming 4.7 release fairs. There's also a comparison against other compilers including the Google 4.6 and Android 4.4 branches. A PDF version is attached to the page. The SPEC 2000 results are still coming in so I'll update the page once they arrive. Everything is generated so we'll update this with each monthly release. -- Michael

13 years, 4 months

[PATCH v5 0/9] Consolidate cpuidle functionality

by Robert Lee

This patch series moves vaious functionality duplicated in platform cpuidle drivers to the core cpuidle driver. Also, the platform irq disabling was removed as it appears that all calls into cpuidle_call_idle will have already called local_irq_disable(). Based on 3.3-rc5 plus recent exynos cpuidle patch: http://www.spinics.net/lists/linux-samsung-soc/msg09467.html v4 submission can be found here: http://lists.infradead.org/pipermail/linux-arm-kernel/2012-January/082742.h… Changes since v4: * Added common cpu_do_idle function to core cpuidle * Added time keep irq en wrapper to core cpuidle * Removed pre/post enter * Re-added platforms that can use new common code. v3 submission can be found here: http://www.spinics.net/lists/arm-kernel/msg156751.html Changes since v3: * Removed drivers/cpuidle/common.c ** Removed the initialization helper functions ** Removed the wrapper used to consolidate time keeping and irq enable/disable * Add time keeping and local_irq_disable handling in cpuidle_call_idle(). * Made necessary modifications to a few platforms that required the most changes ** Note on omap3: changed structure of omap3_idle_drvdata and added per_next_state and per_saved_state vars to accomodate new framework. v2 submission can be found here: http://comments.gmane.org/gmane.linux.ports.arm.kernel/144199 Changes since v2: * Made various code organization and style changes as suggested in v1 review. * Removed at91 use of common code. A separate effort is underway to clean at91 code and the author has offered to convert to common interface as part of those changes (if this common interface is accepted in time). * Made platform cpuidle_driver objects __initdata and dynamically added one persistent instance of this object in common code. * Removed imx5 pm usage of gpc_dvfs clock as it is no longer needed after being enabled during clock initialization. * Re-organized patches. v1 submission can be found here: http://comments.gmane.org/gmane.linux.ports.arm.kernel/142791 Changes since v1: * Common interface moved to drivers/cpuidle and made non arch-specific. * Made various fixes and suggested additions to the common cpuidle code from v1 review. * Added callback for filling in driver_data field as needed. * Modified the various platforms with these changes. Robert Lee (9): cpuidle: Add commonly used functionality for consolidation SH: shmobile: cpuidle consolidation ARM: omap: Consolidate OMAP3 cpuidle time keeping and irq enable ARM: omap: Consolidate OMAP4 cpuidle time keeping and irq enable ARM: shmobile: Consolidate cpuidle functionality ARM: davinci: Consolidate cpuidle functionality ARM: exynos: Consolidate cpuidle functionality ARM: kirkwood: Consolidate cpuidle functionality ARM: at91: Consolidate cpuidle functionality arch/arm/mach-at91/cpuidle.c | 64 +++++++++------------------ arch/arm/mach-davinci/cpuidle.c | 77 +++++++++++++-------------------- arch/arm/mach-exynos/cpuidle.c | 52 ++-------------------- arch/arm/mach-kirkwood/cpuidle.c | 71 +++++++++---------------------- arch/arm/mach-omap2/cpuidle34xx.c | 43 ++++++++----------- arch/arm/mach-omap2/cpuidle44xx.c | 21 +-------- arch/arm/mach-shmobile/cpuidle.c | 22 +--------- arch/sh/kernel/cpu/shmobile/cpuidle.c | 10 +--- drivers/cpuidle/cpuidle.c | 37 +++++++++------ include/linux/cpuidle.h | 55 +++++++++++++++++++++++ 10 files changed, 180 insertions(+), 272 deletions(-)

13 years, 4 months

[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

13 years, 4 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

13 years, 4 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 ---------------------------------

13 years, 4 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

13 years, 4 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

13 years, 4 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

13 years, 4 months

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