Re: [PATCH v8 2/3] watchdog: add watchdog_cpumask sysctl to assist nohz

2015-04-16 Thread Chai Wen
ble_mask); > + > + if (watchdog_enabled && watchdog_thresh) If the new mask is same as the current one, then there is no need to go on ? cpus_equal(watchdog_cpumask, watchdog_cpumask_for_smpboot) or something else ? > + smpboot_update_cpumask_percpu_thread(&watch

Re: [PATCH v2 1/2] Add another clock for use with the soft lockup watchdog.

2015-02-09 Thread Chai Wen
On 01/09/2015 11:34 AM, Cyril Bur wrote: > This permits the use of arch specific clocks for which virtualised kernels can > use their notion of 'running' time, not the elpased wall time which will s/elpased/elapsed/ thanks chai wen > include host execution time. > >

Re: [PATCH resend] ARM: perf: remove useless return and check of idx in counter handling

2014-10-27 Thread Chai Wen
On 10/27/2014 07:54 PM, Will Deacon wrote: > On Fri, Oct 24, 2014 at 08:26:54AM +0100, Chai Wen wrote: >> Hi Will >> >> Ping... > > Sorry, I was on holiday for the latter part of last week. I've applied this > locally and I'll send it via rmk for 3.19,

Re: [PATCH resend] ARM: perf: remove useless return and check of idx in counter handling

2014-10-24 Thread Chai Wen
Hi Will Ping... thanks chai wen On 10/22/2014 08:16 PM, chai wen wrote: > Idx sanity check was once implemented separately in these counter > handling functions and then return value was treated as a judgement. > armv7_pmnc_select_counter() > armv7_pmnc_en

Re: [PATCH resend] ARM: perf: remove useless return and check of idx in counter handling

2014-10-22 Thread Chai Wen
On 10/22/2014 08:31 PM, Mark Rutland wrote: > On Wed, Oct 22, 2014 at 01:16:49PM +0100, chai wen wrote: >> Idx sanity check was once implemented separately in these counter >> handling functions and then return value was treated as a judgement. >> armv

[PATCH resend] ARM: perf: remove useless return and check of idx in counter handling

2014-10-22 Thread chai wen
ff-by: chai wen --- arch/arm/kernel/perf_event_v7.c | 40 +- 1 files changed, 18 insertions(+), 22 deletions(-) diff --git a/arch/arm/kernel/perf_event_v7.c b/arch/arm/kernel/perf_event_v7.c index 116758b..aaf5314 100644 --- a/arch/arm/kernel/perf_event_v7.c

Re: [PATCH 1/2] ARM: perf: armv7 remove useless return and check of idx in counter handling

2014-10-22 Thread Chai Wen
On 10/22/2014 06:47 PM, Mark Rutland wrote: > Hi, > > On Wed, Oct 22, 2014 at 09:21:46AM +0100, chai wen wrote: >> Idx sanity check was once implemented separately in these counter handling >> functions and then return value was treated as a judgement. >>

Re: [PATCH 2/2] ARM: perf: armv7: wrap unsupported arch init functions via micro

2014-10-22 Thread Chai Wen
On 10/22/2014 07:01 PM, Mark Rutland wrote: > Hi, > > On Wed, Oct 22, 2014 at 09:21:47AM +0100, chai wen wrote: >> Signed-off-by: chai wen >> --- >> arch/arm/kernel/perf_event_v7.c | 52 >> +- >> 1 files changed, 13

[PATCH 1/2] ARM: perf: armv7 remove useless return and check of idx in counter handling

2014-10-22 Thread chai wen
() armv7_pmnc_disable_intens() But we do not need to do this now, and the return of idx is useless. Signed-off-by: chai wen --- arch/arm/kernel/perf_event_v7.c | 32 ++-- 1 files changed, 14 insertions(+), 18 deletions(-) diff --git a/arch/arm/kernel/perf_event_v7.c b/arch/arm

[PATCH 2/2] ARM: perf: armv7: wrap unsupported arch init functions via micro

2014-10-22 Thread chai wen
Signed-off-by: chai wen --- arch/arm/kernel/perf_event_v7.c | 52 +- 1 files changed, 13 insertions(+), 39 deletions(-) diff --git a/arch/arm/kernel/perf_event_v7.c b/arch/arm/kernel/perf_event_v7.c index f66a9b8..6c088e8 100644 --- a/arch/arm/kernel

Re: [PATCH] softlockup: make detector be aware of task switch of processes hogging cpu

2014-08-26 Thread Chai Wen
On 08/26/2014 10:22 PM, Don Zickus wrote: > On Tue, Aug 26, 2014 at 08:51:30PM +0800, Chai Wen wrote: >> On 08/22/2014 09:58 AM, Don Zickus wrote: >> >>> On Thu, Aug 21, 2014 at 01:42:22PM +0800, chai wen wrote: >>>> For now, soft lockup detector

Re: [PATCH] softlockup: make detector be aware of task switch of processes hogging cpu

2014-08-26 Thread Chai Wen
On 08/22/2014 09:58 AM, Don Zickus wrote: > On Thu, Aug 21, 2014 at 01:42:22PM +0800, chai wen wrote: >> For now, soft lockup detector warns once for each case of process softlockup. >> But the thread 'watchdog/n' may not always get the cpu at the time slot >> be

Re: [PATCH] softlockup: make detector be aware of task switch of processes hogging cpu

2014-08-21 Thread Chai Wen
On 08/21/2014 01:42 PM, chai wen wrote: > For now, soft lockup detector warns once for each case of process softlockup. > But the thread 'watchdog/n' may not always get the cpu at the time slot > between > the task switch of two processes hogging that cpu to reset soft_

[PATCH] softlockup: make detector be aware of task switch of processes hogging cpu

2014-08-20 Thread chai wen
;, as there may be a different process that is going to hog the cpu. Resolve this by saving/checking the task pointer of the hogging process and use that to reset soft_watchdog_warn too. Signed-off-by: chai wen Signed-off-by: Don Zickus --- kernel/watchdog.c | 16 +++- 1 files changed,

Re: [PATCH 2/5] softlockup: make detector be aware of task switch of processes hogging cpu

2014-08-20 Thread Chai Wen
On 08/19/2014 09:36 AM, Chai Wen wrote: > On 08/19/2014 04:38 AM, Don Zickus wrote: > >> On Mon, Aug 18, 2014 at 09:02:00PM +0200, Ingo Molnar wrote: >>> >>> * Don Zickus wrote: >>> >>>>>>> So I agree with the motivation of this imp

Re: [PATCH 2/5] softlockup: make detector be aware of task switch of processes hogging cpu

2014-08-18 Thread Chai Wen
> I am not sure of the safety about using pid here with namespace. But as to the pointer of process, is there a chance that we got a 'historical' address saved in the 'softlockup_warn_pid(or address)_saved' and the current hogging process happened to get the same task pointer

[tip:perf/watchdog] watchdog: Remove unnecessary header files

2014-08-18 Thread tip-bot for chai wen
Commit-ID: f530504a063cfa028971e4b26ea8e0c32908de25 Gitweb: http://git.kernel.org/tip/f530504a063cfa028971e4b26ea8e0c32908de25 Author: chai wen AuthorDate: Mon, 11 Aug 2014 10:49:23 -0400 Committer: Ingo Molnar CommitDate: Mon, 18 Aug 2014 11:17:46 +0200 watchdog: Remove unnecessary

Re: [PATCH 2/2] softlockup: make detector be aware of task switch of processes hogging cpu

2014-08-05 Thread Chai Wen
On 08/05/2014 11:20 PM, Don Zickus wrote: > On Tue, Aug 05, 2014 at 10:47:57AM +0800, Chai Wen wrote: >> On 08/04/2014 10:31 PM, Don Zickus wrote: >> >>> On Mon, Aug 04, 2014 at 03:36:19PM +0800, chai wen wrote: >>>> >>>> For now, soft loc

Re: [PATCH 2/2] softlockup: make detector be aware of task switch of processes hogging cpu

2014-08-04 Thread Chai Wen
On 08/04/2014 10:31 PM, Don Zickus wrote: > On Mon, Aug 04, 2014 at 03:36:19PM +0800, chai wen wrote: >> >> For now, soft lockup detector warns once for each case of process softlockup. >> But the thread 'watchdog/n' may can not always get cpu at the time slot &

[PATCH 2/2] softlockup: make detector be aware of task switch of processes hogging cpu

2014-08-04 Thread chai wen
;, as there may be a different process that is going to hog the cpu. Is is better for detector to be aware of it. Signed-off-by: chai wen --- kernel/watchdog.c | 18 -- 1 files changed, 16 insertions(+), 2 deletions(-) diff --git a/kernel/watchdog.c b/kernel/watchdog.c index 4c2

[PATCH 1/2] watchdog: remove unnecessary head files

2014-08-04 Thread chai wen
Signed-off-by: chai wen --- kernel/watchdog.c |5 - 1 files changed, 0 insertions(+), 5 deletions(-) diff --git a/kernel/watchdog.c b/kernel/watchdog.c index c3319bd..4c2e11c 100644 --- a/kernel/watchdog.c +++ b/kernel/watchdog.c @@ -15,11 +15,6 @@ #include #include #include

[PATCH RESEND] Drop-FOLL_GET-in-GUP-when-doing-async_pf-in-kvm

2013-10-14 Thread chai wen
n system before. And it works as I see some async_pf happening and the vm works well. But I do not know the exact occasion of the async_pf happening. Thanks. Suggested-by: Gleb Natapov Signed-off-by: Gu zheng Signed-off-by: chai wen --- arch/x86/kvm/x86.c |4 ++-- include/linux/kvm_

Re: [PATCH] Drop FOLL_GET in GUP when doing async_pf in kvm

2013-10-14 Thread chai wen
On 10/14/2013 05:14 PM, Gleb Natapov wrote: > On Mon, Oct 14, 2013 at 05:06:42PM +0800, chai wen wrote: >> Hi Gleb >> Thanks for you comment. >> this new patch is based on git://git.kernel.org/pub/scm/virt/kvm/kvm.git >> queue branch. >> Page pinning is not mandato

[PATCH] Drop FOLL_GET in GUP when doing async_pf in kvm

2013-10-14 Thread chai wen
ke up guests process that is waitting on a page. So drop the FOLL_GET flag in GUP, and do some simplifying in async_pf check/clear processing. thanks. Suggested-by: Gleb Natapov Signed-off-by: Gu zheng Signed-off-by: chai wen --- arch/x86/kvm/x86.c |4 ++-- include/linux/kvm_host.h |

Re: [RFC][PATCH] Drop FOLL_GET in GUP when doing async_pf in kvm

2013-10-11 Thread chai wen
On 10/10/2013 11:15 PM, Gleb Natapov wrote: > On Thu, Oct 10, 2013 at 09:20:15PM +0800, chai wen wrote: >> Hi Gleb >> >> Thanks for you explanation about async_pf in kvm. >> Page pinning is not mandatory in kvm async_pf processing and probably should >> be d

[RFC][PATCH] Drop FOLL_GET in GUP when doing async_pf in kvm

2013-10-10 Thread chai wen
structure to simplify some following async_pf check/clear processing. Thanks. Suggested-by: g...@redhat.com Signed-off-by: chai wen --- arch/x86/kvm/x86.c |5 ++--- include/linux/kvm_host.h |2 +- virt/kvm/async_pf.c | 16 ++-- 3 files changed, 9 insertions(+), 14

Re: [RFC/query] kvm async_pf anon pined pages migration

2013-10-10 Thread chai wen
On 10/08/2013 03:39 PM, Gleb Natapov wrote: > On Tue, Oct 08, 2013 at 02:58:22PM +0800, chai wen wrote: >> On 10/02/2013 12:04 AM, chaiwen wrote: >>> On 09/30/2013 08:51 PM, Gleb Natapov wrote: >>>> On Mon, Sep 30, 2013 at 06:03:07PM +0800, chai wen wrote: >>>

[RFC/query] kvm async_pf anon pined pages migration

2013-09-30 Thread chai wen
Hi all Async page fault in kvm currently pin user pages via get_user_pages. when doing page migration,the method can be found via page->mmapping->a_ops->migratepage to offline old pages and migrate to new pages. As to anonymous page there is no file mapping but a anon_vma.So the migration will fa