Re: [PATCH] rwsem: add rwsem_is_contended

2013-09-16 Thread Ingo Molnar
* Andrew Morton wrote: > On Fri, 30 Aug 2013 10:14:01 -0400 Josef Bacik wrote: > > > Btrfs uses an rwsem to control access to its extent tree. Threads > > will hold a read lock on this rwsem while they scan the extent tree, > > and if need_resched() they will drop the lock and schedule. Th

Re: [PATCH] rwsem: add rwsem_is_contended

2013-09-16 Thread Peter Hurley
On 09/16/2013 09:11 PM, Josef Bacik wrote: On Mon, Sep 16, 2013 at 06:08:42PM -0700, David Daney wrote: On 09/16/2013 05:37 PM, Peter Hurley wrote: On 09/16/2013 08:29 PM, David Daney wrote: On 09/16/2013 05:05 PM, Josef Bacik wrote: On Mon, Sep 16, 2013 at 04:05:47PM -0700, Andrew Morton wro

Re: [PATCH] rwsem: add rwsem_is_contended

2013-09-16 Thread David Daney
On 09/16/2013 05:37 PM, Peter Hurley wrote: On 09/16/2013 08:29 PM, David Daney wrote: On 09/16/2013 05:05 PM, Josef Bacik wrote: On Mon, Sep 16, 2013 at 04:05:47PM -0700, Andrew Morton wrote: On Fri, 30 Aug 2013 10:14:01 -0400 Josef Bacik wrote: Btrfs uses an rwsem to control access to its

Re: [PATCH] rwsem: add rwsem_is_contended

2013-09-16 Thread Josef Bacik
On Mon, Sep 16, 2013 at 06:08:42PM -0700, David Daney wrote: > On 09/16/2013 05:37 PM, Peter Hurley wrote: > >On 09/16/2013 08:29 PM, David Daney wrote: > >>On 09/16/2013 05:05 PM, Josef Bacik wrote: > >>>On Mon, Sep 16, 2013 at 04:05:47PM -0700, Andrew Morton wrote: > On Fri, 30 Aug 2013 10:14

Re: [PATCH] rwsem: add rwsem_is_contended

2013-09-16 Thread Peter Hurley
On 09/16/2013 08:29 PM, David Daney wrote: On 09/16/2013 05:05 PM, Josef Bacik wrote: On Mon, Sep 16, 2013 at 04:05:47PM -0700, Andrew Morton wrote: On Fri, 30 Aug 2013 10:14:01 -0400 Josef Bacik wrote: Btrfs uses an rwsem to control access to its extent tree. Threads will hold a read lock

Re: [PATCH] rwsem: add rwsem_is_contended

2013-09-16 Thread David Daney
On 09/16/2013 05:05 PM, Josef Bacik wrote: On Mon, Sep 16, 2013 at 04:05:47PM -0700, Andrew Morton wrote: On Fri, 30 Aug 2013 10:14:01 -0400 Josef Bacik wrote: Btrfs uses an rwsem to control access to its extent tree. Threads will hold a read lock on this rwsem while they scan the extent tre

Re: [PATCH] rwsem: add rwsem_is_contended

2013-09-16 Thread Josef Bacik
On Mon, Sep 16, 2013 at 04:05:47PM -0700, Andrew Morton wrote: > On Fri, 30 Aug 2013 10:14:01 -0400 Josef Bacik wrote: > > > Btrfs uses an rwsem to control access to its extent tree. Threads will > > hold a > > read lock on this rwsem while they scan the extent tree, and if > > need_resched()

Re: [PATCH] rwsem: add rwsem_is_contended

2013-09-16 Thread Andrew Morton
On Fri, 30 Aug 2013 10:14:01 -0400 Josef Bacik wrote: > Btrfs uses an rwsem to control access to its extent tree. Threads will hold a > read lock on this rwsem while they scan the extent tree, and if need_resched() > they will drop the lock and schedule. The transaction commit needs to take a >

Re: [PATCH] rwsem: add rwsem_is_contended

2013-09-04 Thread Peter Hurley
On 09/03/2013 11:47 AM, Josef Bacik wrote: On Sun, Sep 01, 2013 at 01:32:36AM -0700, Michel Lespinasse wrote: Hi Josef, On Fri, Aug 30, 2013 at 7:14 AM, Josef Bacik wrote: Btrfs uses an rwsem to control access to its extent tree. Threads will hold a read lock on this rwsem while they scan th

Re: [PATCH] rwsem: add rwsem_is_contended

2013-09-04 Thread Josef Bacik
On Wed, Sep 04, 2013 at 07:46:56AM -0400, Peter Hurley wrote: > On 09/03/2013 09:18 AM, Josef Bacik wrote: > >On Mon, Sep 02, 2013 at 01:18:08PM -0400, Peter Hurley wrote: > >>On 09/01/2013 04:32 AM, Michel Lespinasse wrote: > >>>Hi Josef, > >>> > >>>On Fri, Aug 30, 2013 at 7:14 AM, Josef Bacik wr

Re: [PATCH] rwsem: add rwsem_is_contended

2013-09-04 Thread Peter Hurley
On 09/03/2013 09:18 AM, Josef Bacik wrote: On Mon, Sep 02, 2013 at 01:18:08PM -0400, Peter Hurley wrote: On 09/01/2013 04:32 AM, Michel Lespinasse wrote: Hi Josef, On Fri, Aug 30, 2013 at 7:14 AM, Josef Bacik wrote: Btrfs uses an rwsem to control access to its extent tree. Threads will hold

Re: [PATCH] rwsem: add rwsem_is_contended

2013-09-03 Thread Josef Bacik
On Sat, Aug 31, 2013 at 04:51:36PM +0200, Peter Zijlstra wrote: > On Fri, Aug 30, 2013 at 10:14:01AM -0400, Josef Bacik wrote: > > Btrfs uses an rwsem to control access to its extent tree. Threads will > > hold a > > read lock on this rwsem while they scan the extent tree, and if > > need_resche

Re: [PATCH] rwsem: add rwsem_is_contended

2013-09-03 Thread Josef Bacik
On Sun, Sep 01, 2013 at 01:32:36AM -0700, Michel Lespinasse wrote: > Hi Josef, > > On Fri, Aug 30, 2013 at 7:14 AM, Josef Bacik wrote: > > Btrfs uses an rwsem to control access to its extent tree. Threads will > > hold a > > read lock on this rwsem while they scan the extent tree, and if > > n

Re: [PATCH] rwsem: add rwsem_is_contended

2013-09-03 Thread Josef Bacik
On Mon, Sep 02, 2013 at 01:18:08PM -0400, Peter Hurley wrote: > On 09/01/2013 04:32 AM, Michel Lespinasse wrote: > >Hi Josef, > > > >On Fri, Aug 30, 2013 at 7:14 AM, Josef Bacik wrote: > >>Btrfs uses an rwsem to control access to its extent tree. Threads will > >>hold a > >>read lock on this rws

Re: [PATCH] rwsem: add rwsem_is_contended

2013-09-02 Thread Peter Hurley
On 09/01/2013 04:32 AM, Michel Lespinasse wrote: Hi Josef, On Fri, Aug 30, 2013 at 7:14 AM, Josef Bacik wrote: Btrfs uses an rwsem to control access to its extent tree. Threads will hold a read lock on this rwsem while they scan the extent tree, and if need_resched() they will drop the lock a

Re: [PATCH] rwsem: add rwsem_is_contended

2013-09-01 Thread Michel Lespinasse
Hi Josef, On Fri, Aug 30, 2013 at 7:14 AM, Josef Bacik wrote: > Btrfs uses an rwsem to control access to its extent tree. Threads will hold a > read lock on this rwsem while they scan the extent tree, and if need_resched() > they will drop the lock and schedule. The transaction commit needs to

Re: [PATCH] rwsem: add rwsem_is_contended

2013-08-31 Thread Peter Zijlstra
On Fri, Aug 30, 2013 at 10:14:01AM -0400, Josef Bacik wrote: > Btrfs uses an rwsem to control access to its extent tree. Threads will hold a > read lock on this rwsem while they scan the extent tree, and if need_resched() > they will drop the lock and schedule. The transaction commit needs to tak

[PATCH] rwsem: add rwsem_is_contended

2013-08-30 Thread Josef Bacik
Btrfs uses an rwsem to control access to its extent tree. Threads will hold a read lock on this rwsem while they scan the extent tree, and if need_resched() they will drop the lock and schedule. The transaction commit needs to take a write lock for this rwsem for a very short period to switch out