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Message-ID: <AANLkTil-X5IMZMer7fHVPOMalsTJNliv-gMimzKmJ3Od@mail.gmail.com>
Date: Wed, 16 Jun 2010 23:00:37 +0200
From: Sedat Dilek <sedat.dilek@...glemail.com>
To: Andrew Morton <akpm@...ux-foundation.org>
Cc: "Rafael J. Wysocki" <rjw@...k.pl>,
Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
Maciej Rutecki <maciej.rutecki@...il.com>,
Linus Torvalds <torvalds@...ux-foundation.org>,
Kernel Testers List <kernel-testers@...r.kernel.org>,
Network Development <netdev@...r.kernel.org>,
Linux ACPI <linux-acpi@...r.kernel.org>,
Linux PM List <linux-pm@...ts.linux-foundation.org>,
Linux SCSI List <linux-scsi@...r.kernel.org>,
Linux Wireless List <linux-wireless@...r.kernel.org>,
DRI <dri-devel@...ts.sourceforge.net>, dmonakhov@...nvz.org
Subject: Re: 2.6.35-rc2-git2: Reported regressions from 2.6.34
How do cpu-freq related stuff find its way into mainline?
Is there a GIT repository/branch on <git.kernel.org> where you can pull from?
- Sedat -
On Wed, Jun 16, 2010 at 10:42 PM, Andrew Morton
<akpm@...ux-foundation.org> wrote:
> On Wed, 9 Jun 2010 11:22:35 +0200
> "Rafael J. Wysocki" <rjw@...k.pl> wrote:
>
>> On Wednesday 09 June 2010, Sedat Dilek wrote:
>> > The patch from [1] is still missing.
>> >
>> > "cpufreq-call-nr_iowait_cpu-with-disabled-preemption.patch" from
>> > Dmitry Monakhoc
>> >
>> > Tested-by: Sedat Dilek <sedat.dilek@...il.com>
>> > Tested-by Maciej Rutecki <maciej.rutecki@...il.com>
>> >
>> > I have already reported this issue on LKML [2] and cpufreq ML [3].
>> >
>> > - Sedat -
>> >
>> > [1] http://www.spinics.net/lists/cpufreq/msg01631.html
>> > [2] http://lkml.org/lkml/2010/5/31/77
>> > [3] http://www.spinics.net/lists/cpufreq/msg01637.html
>>
>> Thanks, added.
>
> I just merged a different patch whcih should address this:
>
>
> From: Sergey Senozhatsky <sergey.senozhatsky@...il.com>
>
> Fix
>
> BUG: using smp_processor_id() in preemptible [00000000] code: s2disk/3392
> caller is nr_iowait_cpu+0xe/0x1e
> Pid: 3392, comm: s2disk Not tainted 2.6.35-rc3-dbg-00106-ga75e02b #2
> Call Trace:
> [<c1184c55>] debug_smp_processor_id+0xa5/0xbc
> [<c10282a5>] nr_iowait_cpu+0xe/0x1e
> [<c104ab7c>] update_ts_time_stats+0x32/0x6c
> [<c104ac73>] get_cpu_idle_time_us+0x36/0x58
> [<c124229b>] get_cpu_idle_time+0x12/0x74
> [<c1242963>] cpufreq_governor_dbs+0xc3/0x2dc
> [<c1240437>] __cpufreq_governor+0x51/0x85
> [<c1241190>] __cpufreq_set_policy+0x10c/0x13d
> [<c12413d3>] cpufreq_add_dev_interface+0x212/0x233
> [<c1241b1e>] ? handle_update+0x0/0xd
> [<c1241a18>] cpufreq_add_dev+0x34b/0x35a
> [<c103c973>] ? schedule_delayed_work_on+0x11/0x13
> [<c12c14db>] cpufreq_cpu_callback+0x59/0x63
> [<c1042f39>] notifier_call_chain+0x26/0x48
> [<c1042f7d>] __raw_notifier_call_chain+0xe/0x10
> [<c102efb9>] __cpu_notify+0x15/0x29
> [<c102efda>] cpu_notify+0xd/0xf
> [<c12bfb30>] _cpu_up+0xaf/0xd2
> [<c12b3ad4>] enable_nonboot_cpus+0x3d/0x94
> [<c1055eef>] hibernation_snapshot+0x104/0x1a2
> [<c1058b49>] snapshot_ioctl+0x24b/0x53e
> [<c1028ad1>] ? sub_preempt_count+0x7c/0x89
> [<c10ab91d>] vfs_ioctl+0x2e/0x8c
> [<c10588fe>] ? snapshot_ioctl+0x0/0x53e
> [<c10ac2c7>] do_vfs_ioctl+0x42f/0x45a
> [<c10a0ba5>] ? fsnotify_modify+0x4f/0x5a
> [<c11e9dc3>] ? tty_write+0x0/0x1d0
> [<c10a12d6>] ? vfs_write+0xa2/0xda
> [<c10ac333>] sys_ioctl+0x41/0x62
> [<c10027d3>] sysenter_do_call+0x12/0x2d
>
> The initial fix was to use get_cpu/put_cpu in nr_iowait_cpu. However,
> Arjan stated that "the bug is that it needs to be nr_iowait_cpu(int cpu)".
>
> This patch introduces nr_iowait_cpu(int cpu) and changes to it callers.
>
> akpm: addresses about 30,000,000 different bug reports.
>
> Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@...il.com>
> Cc: Arjan van de Ven <arjan@...radead.org>
> Cc: "Rafael J. Wysocki" <rjw@...k.pl>
> Cc: Maxim Levitsky <maximlevitsky@...il.com>
> Cc: Len Brown <len.brown@...el.com>
> Cc: Pavel Machek <pavel@....cz>
> Cc: Jiri Slaby <jslaby@...e.cz>
> Signed-off-by: Andrew Morton <akpm@...ux-foundation.org>
> ---
>
> drivers/cpuidle/governors/menu.c | 10 ++++++++--
> include/linux/sched.h | 2 +-
> kernel/sched.c | 4 ++--
> kernel/time/tick-sched.c | 4 +++-
> 4 files changed, 14 insertions(+), 6 deletions(-)
>
> diff -puN drivers/cpuidle/governors/menu.c~cpuidle-avoid-using-smp_processor_id-in-preemptible-code-nr_iowait_cpu drivers/cpuidle/governors/menu.c
> --- a/drivers/cpuidle/governors/menu.c~cpuidle-avoid-using-smp_processor_id-in-preemptible-code-nr_iowait_cpu
> +++ a/drivers/cpuidle/governors/menu.c
> @@ -137,15 +137,18 @@ static inline int which_bucket(unsigned
> {
> int bucket = 0;
>
> + int cpu = get_cpu();
> /*
> * We keep two groups of stats; one with no
> * IO pending, one without.
> * This allows us to calculate
> * E(duration)|iowait
> */
> - if (nr_iowait_cpu())
> + if (nr_iowait_cpu(cpu))
> bucket = BUCKETS/2;
>
> + put_cpu();
> +
> if (duration < 10)
> return bucket;
> if (duration < 100)
> @@ -169,13 +172,16 @@ static inline int which_bucket(unsigned
> static inline int performance_multiplier(void)
> {
> int mult = 1;
> + int cpu = get_cpu();
>
> /* for higher loadavg, we are more reluctant */
>
> mult += 2 * get_loadavg();
>
> /* for IO wait tasks (per cpu!) we add 5x each */
> - mult += 10 * nr_iowait_cpu();
> + mult += 10 * nr_iowait_cpu(cpu);
> +
> + put_cpu();
>
> return mult;
> }
> diff -puN include/linux/sched.h~cpuidle-avoid-using-smp_processor_id-in-preemptible-code-nr_iowait_cpu include/linux/sched.h
> --- a/include/linux/sched.h~cpuidle-avoid-using-smp_processor_id-in-preemptible-code-nr_iowait_cpu
> +++ a/include/linux/sched.h
> @@ -139,7 +139,7 @@ extern int nr_processes(void);
> extern unsigned long nr_running(void);
> extern unsigned long nr_uninterruptible(void);
> extern unsigned long nr_iowait(void);
> -extern unsigned long nr_iowait_cpu(void);
> +extern unsigned long nr_iowait_cpu(int cpu);
> extern unsigned long this_cpu_load(void);
>
>
> diff -puN kernel/sched.c~cpuidle-avoid-using-smp_processor_id-in-preemptible-code-nr_iowait_cpu kernel/sched.c
> --- a/kernel/sched.c~cpuidle-avoid-using-smp_processor_id-in-preemptible-code-nr_iowait_cpu
> +++ a/kernel/sched.c
> @@ -2864,9 +2864,9 @@ unsigned long nr_iowait(void)
> return sum;
> }
>
> -unsigned long nr_iowait_cpu(void)
> +unsigned long nr_iowait_cpu(int cpu)
> {
> - struct rq *this = this_rq();
> + struct rq *this = cpu_rq(cpu);
> return atomic_read(&this->nr_iowait);
> }
>
> diff -puN kernel/time/tick-sched.c~cpuidle-avoid-using-smp_processor_id-in-preemptible-code-nr_iowait_cpu kernel/time/tick-sched.c
> --- a/kernel/time/tick-sched.c~cpuidle-avoid-using-smp_processor_id-in-preemptible-code-nr_iowait_cpu
> +++ a/kernel/time/tick-sched.c
> @@ -159,10 +159,12 @@ update_ts_time_stats(struct tick_sched *
> ktime_t delta;
>
> if (ts->idle_active) {
> + int cpu = get_cpu();
> delta = ktime_sub(now, ts->idle_entrytime);
> ts->idle_sleeptime = ktime_add(ts->idle_sleeptime, delta);
> - if (nr_iowait_cpu() > 0)
> + if (nr_iowait_cpu(cpu) > 0)
> ts->iowait_sleeptime = ktime_add(ts->iowait_sleeptime, delta);
> + put_cpu();
> ts->idle_entrytime = now;
> }
>
> _
>
>
--
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