Re: [PATCH RFC] locking/mutexes: don't spin on owner when wait list is not NULL.

huang ying writes: > On Sat, Jan 30, 2016 at 9:18 AM, Ding Tianhong > wrote: >> On 2016/1/29 17:53, Peter Zijlstra wrote: >>> On Sun, Jan 24, 2016 at 04:03:50PM +0800, Ding Tianhong wrote: >>> looks good to me, I will try this solution and report the result, thanks everyone. >>> >>>

Re: [PATCH RFC] locking/mutexes: don't spin on owner when wait list is not NULL.

On Sat, Jan 30, 2016 at 9:18 AM, Ding Tianhong wrote: > On 2016/1/29 17:53, Peter Zijlstra wrote: >> On Sun, Jan 24, 2016 at 04:03:50PM +0800, Ding Tianhong wrote: >> >>> looks good to me, I will try this solution and report the result, thanks >>> everyone. >> >> Did you get a change to run with

Re: [PATCH RFC] locking/mutexes: don't spin on owner when wait list is not NULL.

On Sat, Jan 30, 2016 at 9:18 AM, Ding Tianhong wrote: > On 2016/1/29 17:53, Peter Zijlstra wrote: >> On Sun, Jan 24, 2016 at 04:03:50PM +0800, Ding Tianhong wrote: >> >>> looks good to me, I will try this solution and report the result, thanks >>> everyone. >> >> Did you

Re: [PATCH RFC] locking/mutexes: don't spin on owner when wait list is not NULL.

huang ying writes: > On Sat, Jan 30, 2016 at 9:18 AM, Ding Tianhong > wrote: >> On 2016/1/29 17:53, Peter Zijlstra wrote: >>> On Sun, Jan 24, 2016 at 04:03:50PM +0800, Ding Tianhong wrote: >>> looks good to me, I will try this

Re: [PATCH RFC] locking/mutexes: don't spin on owner when wait list is not NULL.

On 2016/1/29 17:53, Peter Zijlstra wrote: > On Sun, Jan 24, 2016 at 04:03:50PM +0800, Ding Tianhong wrote: > >> looks good to me, I will try this solution and report the result, thanks >> everyone. > > Did you get a change to run with this? > > . > I backport this patch to 3.10 lts kernel,

Re: [PATCH RFC] locking/mutexes: don't spin on owner when wait list is not NULL.

On Sun, Jan 24, 2016 at 04:03:50PM +0800, Ding Tianhong wrote: > looks good to me, I will try this solution and report the result, thanks > everyone. Did you get a change to run with this?

Re: [PATCH RFC] locking/mutexes: don't spin on owner when wait list is not NULL.

On Sun, Jan 24, 2016 at 04:03:50PM +0800, Ding Tianhong wrote: > looks good to me, I will try this solution and report the result, thanks > everyone. Did you get a change to run with this?

Re: [PATCH RFC] locking/mutexes: don't spin on owner when wait list is not NULL.

On 2016/1/29 17:53, Peter Zijlstra wrote: > On Sun, Jan 24, 2016 at 04:03:50PM +0800, Ding Tianhong wrote: > >> looks good to me, I will try this solution and report the result, thanks >> everyone. > > Did you get a change to run with this? > > . > I backport this patch to 3.10 lts kernel,

Re: [PATCH RFC] locking/mutexes: don't spin on owner when wait list is not NULL.

On 2016/1/22 21:59, Waiman Long wrote: > On 01/22/2016 06:06 AM, Peter Zijlstra wrote: >> On Fri, Jan 22, 2016 at 11:56:52AM +0100, Peter Zijlstra wrote: >>> On Fri, Jan 22, 2016 at 11:53:12AM +0100, Peter Zijlstra wrote: >>> There might be other details, but this is the one that stood out.

Re: [PATCH RFC] locking/mutexes: don't spin on owner when wait list is not NULL.

On 2016/1/22 21:59, Waiman Long wrote: > On 01/22/2016 06:06 AM, Peter Zijlstra wrote: >> On Fri, Jan 22, 2016 at 11:56:52AM +0100, Peter Zijlstra wrote: >>> On Fri, Jan 22, 2016 at 11:53:12AM +0100, Peter Zijlstra wrote: >>> There might be other details, but this is the one that stood out.

Re: [PATCH RFC] locking/mutexes: don't spin on owner when wait list is not NULL.

On Fri, 22 Jan 2016, Waiman Long wrote: The patch that I sent out is just a proof of concept to make sure that it can fix that particular case. I do plan to refactor it if I decide to go ahead with an official one. Unlike the OSQ, there can be no more than one waiter spinner as the wakeup

Re: [PATCH RFC] locking/mutexes: don't spin on owner when wait list is not NULL.

On 01/22/2016 06:06 AM, Peter Zijlstra wrote: On Fri, Jan 22, 2016 at 11:56:52AM +0100, Peter Zijlstra wrote: On Fri, Jan 22, 2016 at 11:53:12AM +0100, Peter Zijlstra wrote: There might be other details, but this is the one that stood out. I think this also does the wrong thing for

Re: [PATCH RFC] locking/mutexes: don't spin on owner when wait list is not NULL.

On 01/22/2016 03:54 AM, Peter Zijlstra wrote: On Thu, Jan 21, 2016 at 06:02:34PM -0500, Waiman Long wrote: This patch attempts to fix this live-lock condition by enabling the a woken task in the wait list to enter optimistic spinning loop itself with precedence over the ones in the OSQ. This

Re: [PATCH RFC] locking/mutexes: don't spin on owner when wait list is not NULL.

On 01/22/2016 01:09 AM, Davidlohr Bueso wrote: On Thu, 21 Jan 2016, Waiman Long wrote: On 01/21/2016 04:29 AM, Ding Tianhong wrote: I got the vmcore and found that the ifconfig is already in the wait_list of the rtnl_lock for 120 second, but my process could get and release the rtnl_lock

Re: [PATCH RFC] locking/mutexes: don't spin on owner when wait list is not NULL.

On Fri, Jan 22, 2016 at 11:56:52AM +0100, Peter Zijlstra wrote: > On Fri, Jan 22, 2016 at 11:53:12AM +0100, Peter Zijlstra wrote: > > > There might be other details, but this is the one that stood out. > > I think this also does the wrong thing for use_ww_ctx. Something like so? ---

Re: [PATCH RFC] locking/mutexes: don't spin on owner when wait list is not NULL.

On Fri, Jan 22, 2016 at 11:53:12AM +0100, Peter Zijlstra wrote: > There might be other details, but this is the one that stood out. I think this also does the wrong thing for use_ww_ctx.

Re: [PATCH RFC] locking/mutexes: don't spin on owner when wait list is not NULL.

On Fri, Jan 22, 2016 at 02:20:19AM -0800, Jason Low wrote: > --- a/kernel/locking/mutex.c > +++ b/kernel/locking/mutex.c > @@ -543,6 +543,8 @@ __mutex_lock_common(struct mutex *lock, long state, > unsigned int subclass, > lock_contended(>dep_map, ip); > > for (;;) { > +

Re: [PATCH RFC] locking/mutexes: don't spin on owner when wait list is not NULL.

On Fri, 2016-01-22 at 09:54 +0100, Peter Zijlstra wrote: > On Thu, Jan 21, 2016 at 06:02:34PM -0500, Waiman Long wrote: > > This patch attempts to fix this live-lock condition by enabling the > > a woken task in the wait list to enter optimistic spinning loop itself > > with precedence over the

Re: [PATCH RFC] locking/mutexes: don't spin on owner when wait list is not NULL.

On Thu, Jan 21, 2016 at 06:02:34PM -0500, Waiman Long wrote: > This patch attempts to fix this live-lock condition by enabling the > a woken task in the wait list to enter optimistic spinning loop itself > with precedence over the ones in the OSQ. This should prevent the > live-lock > condition

Re: [PATCH RFC] locking/mutexes: don't spin on owner when wait list is not NULL.

On Fri, Jan 22, 2016 at 11:53:12AM +0100, Peter Zijlstra wrote: > There might be other details, but this is the one that stood out. I think this also does the wrong thing for use_ww_ctx.

Re: [PATCH RFC] locking/mutexes: don't spin on owner when wait list is not NULL.

On Fri, Jan 22, 2016 at 11:56:52AM +0100, Peter Zijlstra wrote: > On Fri, Jan 22, 2016 at 11:53:12AM +0100, Peter Zijlstra wrote: > > > There might be other details, but this is the one that stood out. > > I think this also does the wrong thing for use_ww_ctx. Something like so? ---

Re: [PATCH RFC] locking/mutexes: don't spin on owner when wait list is not NULL.

On Fri, 2016-01-22 at 09:54 +0100, Peter Zijlstra wrote: > On Thu, Jan 21, 2016 at 06:02:34PM -0500, Waiman Long wrote: > > This patch attempts to fix this live-lock condition by enabling the > > a woken task in the wait list to enter optimistic spinning loop itself > > with precedence over the

Re: [PATCH RFC] locking/mutexes: don't spin on owner when wait list is not NULL.

On Fri, Jan 22, 2016 at 02:20:19AM -0800, Jason Low wrote: > --- a/kernel/locking/mutex.c > +++ b/kernel/locking/mutex.c > @@ -543,6 +543,8 @@ __mutex_lock_common(struct mutex *lock, long state, > unsigned int subclass, > lock_contended(>dep_map, ip); > > for (;;) { > +

Re: [PATCH RFC] locking/mutexes: don't spin on owner when wait list is not NULL.

On Thu, Jan 21, 2016 at 06:02:34PM -0500, Waiman Long wrote: > This patch attempts to fix this live-lock condition by enabling the > a woken task in the wait list to enter optimistic spinning loop itself > with precedence over the ones in the OSQ. This should prevent the > live-lock > condition

Re: [PATCH RFC] locking/mutexes: don't spin on owner when wait list is not NULL.

On 01/22/2016 03:54 AM, Peter Zijlstra wrote: On Thu, Jan 21, 2016 at 06:02:34PM -0500, Waiman Long wrote: This patch attempts to fix this live-lock condition by enabling the a woken task in the wait list to enter optimistic spinning loop itself with precedence over the ones in the OSQ. This

Re: [PATCH RFC] locking/mutexes: don't spin on owner when wait list is not NULL.

On 01/22/2016 06:06 AM, Peter Zijlstra wrote: On Fri, Jan 22, 2016 at 11:56:52AM +0100, Peter Zijlstra wrote: On Fri, Jan 22, 2016 at 11:53:12AM +0100, Peter Zijlstra wrote: There might be other details, but this is the one that stood out. I think this also does the wrong thing for

Re: [PATCH RFC] locking/mutexes: don't spin on owner when wait list is not NULL.

On 01/22/2016 01:09 AM, Davidlohr Bueso wrote: On Thu, 21 Jan 2016, Waiman Long wrote: On 01/21/2016 04:29 AM, Ding Tianhong wrote: I got the vmcore and found that the ifconfig is already in the wait_list of the rtnl_lock for 120 second, but my process could get and release the rtnl_lock

Re: [PATCH RFC] locking/mutexes: don't spin on owner when wait list is not NULL.

On Fri, 22 Jan 2016, Waiman Long wrote: The patch that I sent out is just a proof of concept to make sure that it can fix that particular case. I do plan to refactor it if I decide to go ahead with an official one. Unlike the OSQ, there can be no more than one waiter spinner as the wakeup

Re: [PATCH RFC] locking/mutexes: don't spin on owner when wait list is not NULL.

On Thu, 21 Jan 2016, Waiman Long wrote: On 01/21/2016 04:29 AM, Ding Tianhong wrote: I got the vmcore and found that the ifconfig is already in the wait_list of the rtnl_lock for 120 second, but my process could get and release the rtnl_lock normally several times in one second, so it means

Re: [PATCH RFC] locking/mutexes: don't spin on owner when wait list is not NULL.

On Thu, Jan 21, 2016 at 06:48:54PM -0800, Davidlohr Bueso wrote: > On Thu, 21 Jan 2016, Paul E. McKenney wrote: > > >I did some testing, which exposed it to the 0day test robot, which > >did note some performance differences. I was hoping that it would > >clear up some instability from other

Re: [PATCH RFC] locking/mutexes: don't spin on owner when wait list is not NULL.

On Thu, 21 Jan 2016, Paul E. McKenney wrote: I did some testing, which exposed it to the 0day test robot, which did note some performance differences. I was hoping that it would clear up some instability from other patches, but no such luck. ;-) Oh, that explains why we got a performance

Re: [PATCH RFC] locking/mutexes: don't spin on owner when wait list is not NULL.

On Thu, Jan 21, 2016 at 01:23:09PM -0800, Tim Chen wrote: > On Thu, 2016-01-21 at 17:29 +0800, Ding Tianhong wrote: > > > > > diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c > > index 0551c21..596b341 100644 > > --- a/kernel/locking/mutex.c > > +++ b/kernel/locking/mutex.c > > @@

Re: [PATCH RFC] locking/mutexes: don't spin on owner when wait list is not NULL.

On 01/21/2016 04:29 AM, Ding Tianhong wrote: I build a script to create several process for ioctl loop calling, the ioctl will calling the kernel function just like: xx_ioctl { ... rtnl_lock(); function(); rtnl_unlock(); ... } The function may sleep several ms, but will not halt, at the same

Re: [PATCH RFC] locking/mutexes: don't spin on owner when wait list is not NULL.

On Thu, 2016-01-21 at 17:29 +0800, Ding Tianhong wrote: > > diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c > index 0551c21..596b341 100644 > --- a/kernel/locking/mutex.c > +++ b/kernel/locking/mutex.c > @@ -256,7 +256,7 @@ static inline int mutex_can_spin_on_owner(struct mutex >

[PATCH RFC] locking/mutexes: don't spin on owner when wait list is not NULL.

I build a script to create several process for ioctl loop calling, the ioctl will calling the kernel function just like: xx_ioctl { ... rtnl_lock(); function(); rtnl_unlock(); ... } The function may sleep several ms, but will not halt, at the same time another user service may calling ifconfig to

Re: [PATCH RFC ] locking/mutexes: don't spin on owner when wait list is not NULL.

On 2016/1/21 15:29, Ingo Molnar wrote: > > Cc:-ed other gents who touched the mutex code recently. Mail quoted below. > Ok, thanks. Ding > Thanks, > > Ingo > > * Ding Tianhong wrote: > >> I build a script to create several process for ioctl loop calling, >> the ioctl will calling

[PATCH RFC] locking/mutexes: don't spin on owner when wait list is not NULL.

I build a script to create several process for ioctl loop calling, the ioctl will calling the kernel function just like: xx_ioctl { ... rtnl_lock(); function(); rtnl_unlock(); ... } The function may sleep several ms, but will not halt, at the same time another user service may calling ifconfig to

Re: [PATCH RFC ] locking/mutexes: don't spin on owner when wait list is not NULL.

On 2016/1/21 15:29, Ingo Molnar wrote: > > Cc:-ed other gents who touched the mutex code recently. Mail quoted below. > Ok, thanks. Ding > Thanks, > > Ingo > > * Ding Tianhong wrote: > >> I build a script to create several process for ioctl loop calling, >>

Re: [PATCH RFC] locking/mutexes: don't spin on owner when wait list is not NULL.

On 01/21/2016 04:29 AM, Ding Tianhong wrote: I build a script to create several process for ioctl loop calling, the ioctl will calling the kernel function just like: xx_ioctl { ... rtnl_lock(); function(); rtnl_unlock(); ... } The function may sleep several ms, but will not halt, at the same

Re: [PATCH RFC] locking/mutexes: don't spin on owner when wait list is not NULL.

On Thu, 2016-01-21 at 17:29 +0800, Ding Tianhong wrote: > > diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c > index 0551c21..596b341 100644 > --- a/kernel/locking/mutex.c > +++ b/kernel/locking/mutex.c > @@ -256,7 +256,7 @@ static inline int mutex_can_spin_on_owner(struct mutex >

Re: [PATCH RFC] locking/mutexes: don't spin on owner when wait list is not NULL.

On Thu, 21 Jan 2016, Paul E. McKenney wrote: I did some testing, which exposed it to the 0day test robot, which did note some performance differences. I was hoping that it would clear up some instability from other patches, but no such luck. ;-) Oh, that explains why we got a performance

Re: [PATCH RFC] locking/mutexes: don't spin on owner when wait list is not NULL.

On Thu, Jan 21, 2016 at 01:23:09PM -0800, Tim Chen wrote: > On Thu, 2016-01-21 at 17:29 +0800, Ding Tianhong wrote: > > > > > diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c > > index 0551c21..596b341 100644 > > --- a/kernel/locking/mutex.c > > +++ b/kernel/locking/mutex.c > > @@

Re: [PATCH RFC] locking/mutexes: don't spin on owner when wait list is not NULL.

On Thu, Jan 21, 2016 at 06:48:54PM -0800, Davidlohr Bueso wrote: > On Thu, 21 Jan 2016, Paul E. McKenney wrote: > > >I did some testing, which exposed it to the 0day test robot, which > >did note some performance differences. I was hoping that it would > >clear up some instability from other

Re: [PATCH RFC] locking/mutexes: don't spin on owner when wait list is not NULL.

On Thu, 21 Jan 2016, Waiman Long wrote: On 01/21/2016 04:29 AM, Ding Tianhong wrote: I got the vmcore and found that the ifconfig is already in the wait_list of the rtnl_lock for 120 second, but my process could get and release the rtnl_lock normally several times in one second, so it means

Re: [PATCH RFC ] locking/mutexes: don't spin on owner when wait list is not NULL.

Cc:-ed other gents who touched the mutex code recently. Mail quoted below. Thanks, Ingo * Ding Tianhong wrote: > I build a script to create several process for ioctl loop calling, > the ioctl will calling the kernel function just like: > xx_ioctl { > ... > rtnl_lock(); > function();

[PATCH RFC ] locking/mutexes: don't spin on owner when wait list is not NULL.

I build a script to create several process for ioctl loop calling, the ioctl will calling the kernel function just like: xx_ioctl { ... rtnl_lock(); function(); rtnl_unlock(); ... } The function may sleep several ms, but will not halt, at the same time another user service may calling ifconfig to

Re: [PATCH RFC ] locking/mutexes: don't spin on owner when wait list is not NULL.

Cc:-ed other gents who touched the mutex code recently. Mail quoted below. Thanks, Ingo * Ding Tianhong wrote: > I build a script to create several process for ioctl loop calling, > the ioctl will calling the kernel function just like: > xx_ioctl { > ... >

[PATCH RFC ] locking/mutexes: don't spin on owner when wait list is not NULL.

I build a script to create several process for ioctl loop calling, the ioctl will calling the kernel function just like: xx_ioctl { ... rtnl_lock(); function(); rtnl_unlock(); ... } The function may sleep several ms, but will not halt, at the same time another user service may calling ifconfig to