Re: [PATCH 3/3] tracing/mm: Don't trace mm_page_pcpu_drain on offline cpus

2015-04-29 Thread Preeti Murthy
On Wed, Apr 29, 2015 at 10:49 PM, Shreyas B Prabhu wrote: > > > On Wednesday 29 April 2015 10:38 PM, Steven Rostedt wrote: >>> I am not sure if its worth the effort now. It doesn't look like any >>> other trace point apart from the above use case will benefit from it. >>> Only smbus_write and smbu

Re: [PATCH 3/3] tracing/mm: Don't trace mm_page_pcpu_drain on offline cpus

2015-04-29 Thread Preeti Murthy
Ccing Paul, On Tue, Apr 28, 2015 at 9:21 PM, Shreyas B. Prabhu wrote: > Since tracepoints use RCU for protection, they must not be called on > offline cpus. trace_mm_page_pcpu_drain can be called on an offline cpu > in this scenario caught by LOCKDEP: > > === > [ INF

Re: [PATCH 2/3] tracing/mm: Don't trace mm_page_free on offline cpus

2015-04-29 Thread Preeti Murthy
On Wed, Apr 29, 2015 at 2:36 PM, Preeti Murthy wrote: > Ccing Paul, > > On Tue, Apr 28, 2015 at 9:21 PM, Shreyas B. Prabhu > wrote: >> Since tracepoints use RCU for protection, they must not be called on >> offline cpus. trace_mm_page_free can be called on an offline

Re: [PATCH 2/3] tracing/mm: Don't trace mm_page_free on offline cpus

2015-04-29 Thread Preeti Murthy
Ccing Paul, On Tue, Apr 28, 2015 at 9:21 PM, Shreyas B. Prabhu wrote: > Since tracepoints use RCU for protection, they must not be called on > offline cpus. trace_mm_page_free can be called on an offline cpu in > this scenario caught by LOCKDEP: > > === > [ INFO: sus

Re: [PATCH 1/3] tracing/mm: Don't trace kmem_cache_free on offline cpus

2015-04-29 Thread Preeti Murthy
Ccing Paul, On Tue, Apr 28, 2015 at 9:21 PM, Shreyas B. Prabhu wrote: > Since tracepoints use RCU for protection, they must not be called on > offline cpus. trace_kmem_cache_free can be called on an offline cpu in > this scenario caught by LOCKDEP: > > === > [ INFO: su

Re: [nohz] 2a16fc93d2c: kernel lockup on idle injection

2014-12-17 Thread Preeti Murthy
Hi Thomas, On Tue, Dec 16, 2014 at 6:19 PM, Thomas Gleixner wrote: > On Tue, 16 Dec 2014, Preeti U Murthy wrote: >> As far as I can see, the primary purpose of tick_nohz_irq_enter()/exit() >> paths was to take care of *tick stopped* cases. >> >> Before handling interrupts we would want jiffies to

Re: [PATCH V2 3/5] cpuidle: idle: menu: Don't reflect when a state selection failed

2014-10-28 Thread Preeti Murthy
On Thu, Oct 23, 2014 at 2:31 PM, Daniel Lezcano wrote: > In the current code, the check to reflect or not the outcoming state is done > against the idle state which has been chosen and its value. > > Instead of doing a check in each of the reflect functions, just don't call > reflect > if somethi

Re: [PATCH 2/5] sched: idle: Get the next timer event and pass it the cpuidle framework

2014-10-27 Thread Preeti Murthy
Hi Daniel, On Mon, Oct 20, 2014 at 9:55 PM, Daniel Lezcano wrote: > Following the logic of the previous patch, retrieve from the idle task the > expected timer sleep duration and pass it to the cpuidle framework. > > Take the opportunity to remove the unused headers in the menu.c file. > > This p

Re: [PATCH V2 1/5] sched: idle: cpuidle: Check the latency req before idle

2014-10-27 Thread Preeti Murthy
Hi Daniel, On Thu, Oct 23, 2014 at 2:31 PM, Daniel Lezcano wrote: > When the pmqos latency requirement is set to zero that means "poll in all the > cases". > > That is correctly implemented on x86 but not on the other archs. > > As how is written the code, if the latency request is zero, the gove

Re: [PATCH] sched: Do not stop cpu in set_cpus_allowed_ptr() if task is not running

2014-09-15 Thread Preeti Murthy
Hi Kirill, Which tree is this patch based on? __migrate_task() does a double_rq_lock/unlock() today in mainline, doesn't it? I don't however see that in your patch. Regards Preeti U Murthy On Fri, Sep 12, 2014 at 4:33 PM, Kirill Tkhai wrote: > > If a task is queued but not running on it rq, we

Re: [PATCH] sched: fix exec_start/task_hot on migrated tasks

2014-05-16 Thread Preeti Murthy
Hi, On Fri, May 16, 2014 at 1:34 PM, Peter Zijlstra wrote: > On Thu, May 15, 2014 at 03:59:20PM -0700, Ben Segall wrote: >> task_hot checks exec_start on any runnable task, but if it has been >> migrated since the it last ran, then exec_start is a clock_task from >> another cpu. If the old cpu's

Re: [PATCH 5/6] sched: remove remaining power to the CPU

2014-05-16 Thread Preeti Murthy
Hi Nicolas, You might want to change the subject. s/sched: remove remaining power to the CPU/ sched: remove remaining usage of cpu *power* . The subject has to explicitly specify in some way that it is a change made to the terminology. Regards Preeti U Murthy On Thu, May 15, 2014 at 2:27 AM,

Re: [RESEND PATCH V5 0/8] remove cpu_load idx

2014-05-06 Thread Preeti Murthy
Hi Morten, Peter, Alex, In a similar context, I noticed that /proc/loadavg makes use of avenrun[] array which keeps track of the history of the global load average. This however makes use of the sum of nr_running + nr_uninterruptible per cpu. Why are we not using the cpu_load[] array here which al

Re: [PATCH RFC/TEST] sched: make sync affine wakeups work

2014-05-04 Thread Preeti Murthy
Hi Rik, Mike On Fri, May 2, 2014 at 12:00 PM, Rik van Riel wrote: > On 05/02/2014 02:13 AM, Mike Galbraith wrote: >> On Fri, 2014-05-02 at 00:42 -0400, Rik van Riel wrote: >> >>> Whether or not this is the right thing to do remains to be seen, >>> but it does allow us to verify whether or not the

Re: [PATCH 1/3] sched, balancing: Update rq->max_idle_balance_cost whenever newidle balance is attempted

2014-04-27 Thread Preeti Murthy
Hi Jason, Peter, The below patch looks good to me except for one point. In idle_balance() the below code snippet does not look right: - if (pulled_task || time_after(jiffies, this_rq->next_balance)) { - /* - * We are going idle. next_balance may be set based on - * a busy processor. So reset nex

Re: [Query]: hrtimers: why don't we consider hrtimers in get_next_timer_interrupt()

2014-04-23 Thread Preeti Murthy
Hi Viresh, On Wed, Apr 23, 2014 at 3:08 PM, Viresh Kumar wrote: > Hi, > > File: hrtimer.c > Function: hrtimer_get_next_event() > > I was looking closely at what's waking up my system and > found this piece of code: > > ktime_t hrtimer_get_next_event(void) > { > if (!hrtimer_hres_active())

Re: [Query]: tick-sched: why don't we stop tick when we are running idle task?

2014-04-14 Thread Preeti Murthy
Hi Viresh, I am not too sure about the complexity or the worthiness of this patch but just wanted to add that care must be taken to migrate the tick_sched_timer of all the remote CPUs off a hotplugged out CPU if the latter was keeping their time thus far. In the normal scenario I am guessing the t

Re: [RFC PATCH 0/2] sched: proposal for idlestat scheduler benchmarking tool

2014-03-25 Thread Preeti Murthy
Hi Zoran, I understand that this approach is non-intrusive with the running workload. However it would be nice to know how my system is behaving in terms of power efficiency at a given instance of time and accordingly I can take action to kill a few applications to save power, as against knowing

Re: [PATCH 1/2] nohz: use seqlock to avoid race on idle time stats

2014-03-24 Thread Preeti Murthy
Hi Hidetoshi, The patch looks good to me except the comments around the monotonicity of the return value of the idle stats observer. I am unable to relate them to the dependency on nr_iowait_cpu. I see that when the reader queries for the idle stats and calls get_cpu_idle_time_us(), the nr_iowait

Re: [PATCH 4/4] sched: Revert commit 4c6c4e38c4e9

2014-03-19 Thread Preeti Murthy
On Sat, Mar 15, 2014 at 3:45 AM, Kirill Tkhai wrote: > This reverts commit 4c6c4e38c4e9 [sched/core: Fix endless loop in > pick_next_task()], which is not necessary after [sched/rt: Substract number > of tasks of throttled queues from rq->nr_running] Reviewed-by: Preeti U Murthy > > Signed-off-b

Re: [PATCH 1/4] sched/rt: Sum number of all children tasks in hierarhy at rt_nr_running

2014-03-18 Thread Preeti Murthy
On Sat, Mar 15, 2014 at 3:44 AM, Kirill Tkhai wrote: > {inc,dec}_rt_tasks used to count entities which are directly queued > on rt_rq. If an entity was not a task (i.e., it is some queue), its > children were not counted. Its always the case that a task is queued right, never a sched entity? When

Re: [GIT Pull] timer fixes for 3.14

2014-02-17 Thread Preeti Murthy
Hi Thomas, With regard to the patch: "tick: Clear broadcast pending bit when switching to oneshot" isn't BROADCAST_EXIT called atleast after initializing the high resolution timers while handling the broadcast IPI and before re-entering idle? This should clear the cpu bit in the pending mask right

Re: [PATCH V2 3/3] sched: Move idle_stamp up to the core

2014-02-10 Thread Preeti Murthy
Hi Daniel, On Fri, Feb 7, 2014 at 4:40 AM, Daniel Lezcano wrote: > The idle_balance modifies the idle_stamp field of the rq, making this > information to be shared across core.c and fair.c. As we can know if the > cpu is going to idle or not with the previous patch, let's encapsulate the > idle_s

Re: [PATCH V2 2/3] sched: Fix race in idle_balance()

2014-02-10 Thread Preeti Murthy
HI Daniel, Isn't the only scenario where another cpu can put an idle task on our runqueue, in nohz_idle_balance() where only the cpus in the nohz.idle_cpus_mask are iterated through. But for the case that this patch is addressing, the cpu in question is not yet a part of the nohz.idle_cpus_mask ri

Re: [Update][PATCH 2/2] clocksource: Make clocksource register functions void

2014-02-10 Thread Preeti Murthy
Hi Yijing, For the powerpc part: Acked-by: Preeti U Murthy On Mon, Feb 10, 2014 at 7:28 AM, Yijing Wang wrote: > Currently, clocksource_register() and __clocksource_register_scale() > functions always return 0, it's pointless, make functions void. > And remove the dead code that check the cloc

Re: [RFC PATCH 3/3] idle: store the idle state index in the struct rq

2014-01-31 Thread Preeti Murthy
Hi, On Thu, Jan 30, 2014 at 10:55 PM, Daniel Lezcano wrote: > On 01/30/2014 05:35 PM, Peter Zijlstra wrote: >> >> On Thu, Jan 30, 2014 at 05:27:54PM +0100, Daniel Lezcano wrote: >>> >>> struct cpuidle_state *state = &drv->states[rq->index]; >>> >>> And from the state, we have the following inform

Re: [GIT PULL timers] Timer-wheel bandaids^Wcommits

2014-01-29 Thread Preeti Murthy
Hi Paul, The commit id:e1d690cdc07637131ba4334: timers: Track total number of timers in list has a minor glitch in the changelog. I am referring to your git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git rcu/timers branch. "even if ->active_timers is zero, there might well be *n

Re: Is it ok for deferrable timer wakeup the idle cpu?

2014-01-28 Thread Preeti Murthy
Hi, On Thu, Jan 23, 2014 at 11:22 AM, Viresh Kumar wrote: > Hi Guys, > > So the first question is why cpufreq needs it and is it really stupid? > Yes, it is stupid but that's how its implemented since a long time. It does > so to get data about the load on CPUs, so that freq can be scaled up/dow

Re: [PATCH] sched: Calculate effective load even if local weight is 0

2014-01-12 Thread Preeti Murthy
Hi, On Mon, Jan 6, 2014 at 5:09 PM, Mel Gorman wrote: > (Rik, you authored this patch so it should be sent from you and needs a > signed-off assuming people are ok with the changelog.) > > Thomas Hellstrom bisected a regression where erratic 3D performance is > experienced on virtual machines as

Re: [PATCH] cpuidle: Measure idle state durations with monotonic clock

2012-11-15 Thread Preeti Murthy
Hi all, The code looks correct and inviting to me as it has led to good cleanups. I dont think passing 0 as the argument to the function sched_clock_idle_wakeup_event() should lead to problems,as it does not do anything useful with the passed arguments. My only curiosity is what was the purpose o

Re: [RFC PATCH 2/3] sched: power aware load balance,

2012-11-11 Thread Preeti Murthy
Hi Alex I apologise for the delay in replying . On Wed, Nov 7, 2012 at 6:57 PM, Alex Shi wrote: > On 11/07/2012 12:37 PM, Preeti Murthy wrote: >> Hi Alex, >> >> What I am concerned about in this patchset as Peter also >> mentioned in the previous discussion of your ap

Re: [RFC PATCH 2/3] sched: power aware load balance,

2012-11-06 Thread Preeti Murthy
Hi Alex, What I am concerned about in this patchset as Peter also mentioned in the previous discussion of your approach (https://lkml.org/lkml/2012/8/13/139) is that: 1.Using nr_running of two different sched groups to decide which one can be group_leader or group_min might not be be the right ap

Re: [patch 02/16] sched: maintain per-rq runnable averages

2012-10-28 Thread Preeti Murthy
Hi Paul, Ben, A few queries regarding this patch: 1.What exactly is the significance of introducing sched_avg structure for a runqueue? If I have understood correctly, sched_avg keeps track of how long a task has been active, how long has it been serviced by the processor and its lifetime.H

Re: [RFC PATCH 00/13] sched: Integrating Per-entity-load-tracking with the core scheduler

2012-10-25 Thread Preeti Murthy
The benchmark: /* * test.c - Simulate workloads that load the CPU differently * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation; version 2 of the License. * * This pr