Re: [PATCH 5/8] thp, mm: locking tail page is a bug

2013-07-18 Thread Hugh Dickins
On Wed, 17 Jul 2013, Dave Jones wrote: > On Wed, Jul 17, 2013 at 05:58:13PM -0700, Hugh Dickins wrote: > > On Wed, 17 Jul 2013, Dave Hansen wrote: > > > On 07/17/2013 02:09 PM, Andrew Morton wrote: > > > > lock_page() is a pretty commonly called function, and I assume quite a > > > > lot of

Re: [PATCH 5/8] thp, mm: locking tail page is a bug

2013-07-18 Thread Hugh Dickins
On Wed, 17 Jul 2013, Dave Jones wrote: On Wed, Jul 17, 2013 at 05:58:13PM -0700, Hugh Dickins wrote: On Wed, 17 Jul 2013, Dave Hansen wrote: On 07/17/2013 02:09 PM, Andrew Morton wrote: lock_page() is a pretty commonly called function, and I assume quite a lot of people run with

Re: [PATCH 5/8] thp, mm: locking tail page is a bug

2013-07-17 Thread Dave Jones
On Wed, Jul 17, 2013 at 05:58:13PM -0700, Hugh Dickins wrote: > On Wed, 17 Jul 2013, Dave Hansen wrote: > > On 07/17/2013 02:09 PM, Andrew Morton wrote: > > > lock_page() is a pretty commonly called function, and I assume quite a > > > lot of people run with CONFIG_DEBUG_VM=y. > > > > > >

Re: [PATCH 5/8] thp, mm: locking tail page is a bug

2013-07-17 Thread Hugh Dickins
On Wed, 17 Jul 2013, Dave Hansen wrote: > On 07/17/2013 02:09 PM, Andrew Morton wrote: > > lock_page() is a pretty commonly called function, and I assume quite a > > lot of people run with CONFIG_DEBUG_VM=y. > > > > Is the overhead added by this patch really worthwhile? > > I always thought of

Re: [PATCH 5/8] thp, mm: locking tail page is a bug

2013-07-17 Thread Dave Hansen
On 07/17/2013 02:09 PM, Andrew Morton wrote: > lock_page() is a pretty commonly called function, and I assume quite a > lot of people run with CONFIG_DEBUG_VM=y. > > Is the overhead added by this patch really worthwhile? I always thought of it as a developer-only thing. I don't think any of the

Re: [PATCH 5/8] thp, mm: locking tail page is a bug

2013-07-17 Thread Kirill A. Shutemov
Andrew Morton wrote: > On Mon, 15 Jul 2013 13:47:51 +0300 "Kirill A. Shutemov" > wrote: > > > From: "Kirill A. Shutemov" > > > > Locking head page means locking entire compound page. > > If we try to lock tail page, something went wrong. > > > > .. > > > > --- a/mm/filemap.c > > +++

Re: [PATCH 5/8] thp, mm: locking tail page is a bug

2013-07-17 Thread Andrew Morton
On Mon, 15 Jul 2013 13:47:51 +0300 "Kirill A. Shutemov" wrote: > From: "Kirill A. Shutemov" > > Locking head page means locking entire compound page. > If we try to lock tail page, something went wrong. > > .. > > --- a/mm/filemap.c > +++ b/mm/filemap.c > @@ -639,6 +639,7 @@ void

Re: [PATCH 5/8] thp, mm: locking tail page is a bug

2013-07-17 Thread Andrew Morton
On Mon, 15 Jul 2013 13:47:51 +0300 Kirill A. Shutemov kirill.shute...@linux.intel.com wrote: From: Kirill A. Shutemov kirill.shute...@linux.intel.com Locking head page means locking entire compound page. If we try to lock tail page, something went wrong. .. --- a/mm/filemap.c +++

Re: [PATCH 5/8] thp, mm: locking tail page is a bug

2013-07-17 Thread Kirill A. Shutemov
Andrew Morton wrote: On Mon, 15 Jul 2013 13:47:51 +0300 Kirill A. Shutemov kirill.shute...@linux.intel.com wrote: From: Kirill A. Shutemov kirill.shute...@linux.intel.com Locking head page means locking entire compound page. If we try to lock tail page, something went wrong. ..

Re: [PATCH 5/8] thp, mm: locking tail page is a bug

2013-07-17 Thread Dave Hansen
On 07/17/2013 02:09 PM, Andrew Morton wrote: lock_page() is a pretty commonly called function, and I assume quite a lot of people run with CONFIG_DEBUG_VM=y. Is the overhead added by this patch really worthwhile? I always thought of it as a developer-only thing. I don't think any of the big

Re: [PATCH 5/8] thp, mm: locking tail page is a bug

2013-07-17 Thread Hugh Dickins
On Wed, 17 Jul 2013, Dave Hansen wrote: On 07/17/2013 02:09 PM, Andrew Morton wrote: lock_page() is a pretty commonly called function, and I assume quite a lot of people run with CONFIG_DEBUG_VM=y. Is the overhead added by this patch really worthwhile? I always thought of it as a

Re: [PATCH 5/8] thp, mm: locking tail page is a bug

2013-07-17 Thread Dave Jones
On Wed, Jul 17, 2013 at 05:58:13PM -0700, Hugh Dickins wrote: On Wed, 17 Jul 2013, Dave Hansen wrote: On 07/17/2013 02:09 PM, Andrew Morton wrote: lock_page() is a pretty commonly called function, and I assume quite a lot of people run with CONFIG_DEBUG_VM=y. Is the overhead

[PATCH 5/8] thp, mm: locking tail page is a bug

2013-07-15 Thread Kirill A. Shutemov
From: "Kirill A. Shutemov" Locking head page means locking entire compound page. If we try to lock tail page, something went wrong. Signed-off-by: Kirill A. Shutemov Acked-by: Dave Hansen --- mm/filemap.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/mm/filemap.c b/mm/filemap.c index

[PATCH 5/8] thp, mm: locking tail page is a bug

2013-07-15 Thread Kirill A. Shutemov
From: Kirill A. Shutemov kirill.shute...@linux.intel.com Locking head page means locking entire compound page. If we try to lock tail page, something went wrong. Signed-off-by: Kirill A. Shutemov kirill.shute...@linux.intel.com Acked-by: Dave Hansen dave.han...@linux.intel.com --- mm/filemap.c

[PATCH 5/8] thp, mm: locking tail page is a bug

2013-06-11 Thread Kirill A. Shutemov
From: "Kirill A. Shutemov" Locking head page means locking entire compound page. If we try to lock tail page, something went wrong. Signed-off-by: Kirill A. Shutemov Acked-by: Dave Hansen --- mm/filemap.c |2 ++ 1 file changed, 2 insertions(+) diff --git a/mm/filemap.c b/mm/filemap.c

[PATCH 5/8] thp, mm: locking tail page is a bug

2013-06-11 Thread Kirill A. Shutemov
From: Kirill A. Shutemov kirill.shute...@linux.intel.com Locking head page means locking entire compound page. If we try to lock tail page, something went wrong. Signed-off-by: Kirill A. Shutemov kirill.shute...@linux.intel.com Acked-by: Dave Hansen dave.han...@linux.intel.com --- mm/filemap.c