Re: [PATCH] Swap delay accounting, include lock_page() delays

2007-10-31 Thread Balbir Singh
Nick Piggin wrote:
> On Wednesday 31 October 2007 18:41, Nick Piggin wrote:
>> On Wednesday 31 October 2007 18:52, Balbir Singh wrote:
>>> Reported-by: Nick Piggin <[EMAIL PROTECTED]>
>>>
>>> The delay incurred in lock_page() should also be accounted in swap delay
>>> accounting
>>>
>>> Signed-off-by: Balbir Singh <[EMAIL PROTECTED]>
>> Ah right, I forgot to resend this one, sorry. Thanks for remembering.
> 
> Although, I think I had a bit more detail in the changelog which
> I think should be kept.
> 
> Basically, swap delay accounting seems quite broken as of now,
> because what it is counting is the time required to allocate a new
> page and submit the IO, but not actually the time to perform the IO
> at all (which I'd expect will be significant, although possibly in
> some workloads the actual page allocation will dominate).
> 

This looks quite good to me. I'm off attending a wedding, I'll resend
the patch when I am back.

-- 
Warm Regards,
Balbir Singh
Linux Technology Center
IBM, ISTL
-
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Re: [PATCH] Swap delay accounting, include lock_page() delays

2007-10-31 Thread Nick Piggin
On Wednesday 31 October 2007 18:41, Nick Piggin wrote:
> On Wednesday 31 October 2007 18:52, Balbir Singh wrote:
> > Reported-by: Nick Piggin <[EMAIL PROTECTED]>
> >
> > The delay incurred in lock_page() should also be accounted in swap delay
> > accounting
> >
> > Signed-off-by: Balbir Singh <[EMAIL PROTECTED]>
>
> Ah right, I forgot to resend this one, sorry. Thanks for remembering.

Although, I think I had a bit more detail in the changelog which
I think should be kept.

Basically, swap delay accounting seems quite broken as of now,
because what it is counting is the time required to allocate a new
page and submit the IO, but not actually the time to perform the IO
at all (which I'd expect will be significant, although possibly in
some workloads the actual page allocation will dominate).

>
> > ---
> >
> >  mm/memory.c |2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff -puN mm/swapfile.c~fix-delay-accounting-swap-accounting
> > mm/swapfile.c diff -puN mm/memory.c~fix-delay-accounting-swap-accounting
> > mm/memory.c ---
> > linux-2.6-latest/mm/memory.c~fix-delay-accounting-swap-accounting   2007-10
> >-3 1 12:58:05.0 +0530 +++
> > linux-2.6-latest-balbir/mm/memory.c 2007-10-31 13:02:50.0 +0530
> > @@ -2084,9 +2084,9 @@ static int do_swap_page(struct mm_struct
> > count_vm_event(PGMAJFAULT);
> > }
> >
> > -   delayacct_clear_flag(DELAYACCT_PF_SWAPIN);
> > mark_page_accessed(page);
> > lock_page(page);
> > +   delayacct_clear_flag(DELAYACCT_PF_SWAPIN);
> >
> > /*
> >  * Back out if somebody else already faulted in this pte.
> > _

-
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Re: [PATCH] Swap delay accounting, include lock_page() delays

2007-10-31 Thread Nick Piggin
On Wednesday 31 October 2007 18:52, Balbir Singh wrote:
> Reported-by: Nick Piggin <[EMAIL PROTECTED]>
>
> The delay incurred in lock_page() should also be accounted in swap delay
> accounting
>
> Signed-off-by: Balbir Singh <[EMAIL PROTECTED]>

Ah right, I forgot to resend this one, sorry. Thanks for remembering.


> ---
>
>  mm/memory.c |2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff -puN mm/swapfile.c~fix-delay-accounting-swap-accounting mm/swapfile.c
> diff -puN mm/memory.c~fix-delay-accounting-swap-accounting mm/memory.c
> ---
> linux-2.6-latest/mm/memory.c~fix-delay-accounting-swap-accounting 
> 2007-10-3
>1 12:58:05.0 +0530 +++
> linux-2.6-latest-balbir/mm/memory.c   2007-10-31 13:02:50.0 +0530 @@
> -2084,9 +2084,9 @@ static int do_swap_page(struct mm_struct
>   count_vm_event(PGMAJFAULT);
>   }
>
> - delayacct_clear_flag(DELAYACCT_PF_SWAPIN);
>   mark_page_accessed(page);
>   lock_page(page);
> + delayacct_clear_flag(DELAYACCT_PF_SWAPIN);
>
>   /*
>* Back out if somebody else already faulted in this pte.
> _
-
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[PATCH] Swap delay accounting, include lock_page() delays

2007-10-31 Thread Balbir Singh


Reported-by: Nick Piggin <[EMAIL PROTECTED]>

The delay incurred in lock_page() should also be accounted in swap delay
accounting

Signed-off-by: Balbir Singh <[EMAIL PROTECTED]>
---

 mm/memory.c |2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff -puN mm/swapfile.c~fix-delay-accounting-swap-accounting mm/swapfile.c
diff -puN mm/memory.c~fix-delay-accounting-swap-accounting mm/memory.c
--- linux-2.6-latest/mm/memory.c~fix-delay-accounting-swap-accounting   
2007-10-31 12:58:05.0 +0530
+++ linux-2.6-latest-balbir/mm/memory.c 2007-10-31 13:02:50.0 +0530
@@ -2084,9 +2084,9 @@ static int do_swap_page(struct mm_struct
count_vm_event(PGMAJFAULT);
}
 
-   delayacct_clear_flag(DELAYACCT_PF_SWAPIN);
mark_page_accessed(page);
lock_page(page);
+   delayacct_clear_flag(DELAYACCT_PF_SWAPIN);
 
/*
 * Back out if somebody else already faulted in this pte.
_

-- 
Warm Regards,
Balbir Singh
Linux Technology Center
IBM, ISTL
-
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[PATCH] Swap delay accounting, include lock_page() delays

2007-10-31 Thread Balbir Singh


Reported-by: Nick Piggin [EMAIL PROTECTED]

The delay incurred in lock_page() should also be accounted in swap delay
accounting

Signed-off-by: Balbir Singh [EMAIL PROTECTED]
---

 mm/memory.c |2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff -puN mm/swapfile.c~fix-delay-accounting-swap-accounting mm/swapfile.c
diff -puN mm/memory.c~fix-delay-accounting-swap-accounting mm/memory.c
--- linux-2.6-latest/mm/memory.c~fix-delay-accounting-swap-accounting   
2007-10-31 12:58:05.0 +0530
+++ linux-2.6-latest-balbir/mm/memory.c 2007-10-31 13:02:50.0 +0530
@@ -2084,9 +2084,9 @@ static int do_swap_page(struct mm_struct
count_vm_event(PGMAJFAULT);
}
 
-   delayacct_clear_flag(DELAYACCT_PF_SWAPIN);
mark_page_accessed(page);
lock_page(page);
+   delayacct_clear_flag(DELAYACCT_PF_SWAPIN);
 
/*
 * Back out if somebody else already faulted in this pte.
_

-- 
Warm Regards,
Balbir Singh
Linux Technology Center
IBM, ISTL
-
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Re: [PATCH] Swap delay accounting, include lock_page() delays

2007-10-31 Thread Nick Piggin
On Wednesday 31 October 2007 18:52, Balbir Singh wrote:
 Reported-by: Nick Piggin [EMAIL PROTECTED]

 The delay incurred in lock_page() should also be accounted in swap delay
 accounting

 Signed-off-by: Balbir Singh [EMAIL PROTECTED]

Ah right, I forgot to resend this one, sorry. Thanks for remembering.


 ---

  mm/memory.c |2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)

 diff -puN mm/swapfile.c~fix-delay-accounting-swap-accounting mm/swapfile.c
 diff -puN mm/memory.c~fix-delay-accounting-swap-accounting mm/memory.c
 ---
 linux-2.6-latest/mm/memory.c~fix-delay-accounting-swap-accounting 
 2007-10-3
1 12:58:05.0 +0530 +++
 linux-2.6-latest-balbir/mm/memory.c   2007-10-31 13:02:50.0 +0530 @@
 -2084,9 +2084,9 @@ static int do_swap_page(struct mm_struct
   count_vm_event(PGMAJFAULT);
   }

 - delayacct_clear_flag(DELAYACCT_PF_SWAPIN);
   mark_page_accessed(page);
   lock_page(page);
 + delayacct_clear_flag(DELAYACCT_PF_SWAPIN);

   /*
* Back out if somebody else already faulted in this pte.
 _
-
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Re: [PATCH] Swap delay accounting, include lock_page() delays

2007-10-31 Thread Nick Piggin
On Wednesday 31 October 2007 18:41, Nick Piggin wrote:
 On Wednesday 31 October 2007 18:52, Balbir Singh wrote:
  Reported-by: Nick Piggin [EMAIL PROTECTED]
 
  The delay incurred in lock_page() should also be accounted in swap delay
  accounting
 
  Signed-off-by: Balbir Singh [EMAIL PROTECTED]

 Ah right, I forgot to resend this one, sorry. Thanks for remembering.

Although, I think I had a bit more detail in the changelog which
I think should be kept.

Basically, swap delay accounting seems quite broken as of now,
because what it is counting is the time required to allocate a new
page and submit the IO, but not actually the time to perform the IO
at all (which I'd expect will be significant, although possibly in
some workloads the actual page allocation will dominate).


  ---
 
   mm/memory.c |2 +-
   1 file changed, 1 insertion(+), 1 deletion(-)
 
  diff -puN mm/swapfile.c~fix-delay-accounting-swap-accounting
  mm/swapfile.c diff -puN mm/memory.c~fix-delay-accounting-swap-accounting
  mm/memory.c ---
  linux-2.6-latest/mm/memory.c~fix-delay-accounting-swap-accounting   2007-10
 -3 1 12:58:05.0 +0530 +++
  linux-2.6-latest-balbir/mm/memory.c 2007-10-31 13:02:50.0 +0530
  @@ -2084,9 +2084,9 @@ static int do_swap_page(struct mm_struct
  count_vm_event(PGMAJFAULT);
  }
 
  -   delayacct_clear_flag(DELAYACCT_PF_SWAPIN);
  mark_page_accessed(page);
  lock_page(page);
  +   delayacct_clear_flag(DELAYACCT_PF_SWAPIN);
 
  /*
   * Back out if somebody else already faulted in this pte.
  _

-
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Re: [PATCH] Swap delay accounting, include lock_page() delays

2007-10-31 Thread Balbir Singh
Nick Piggin wrote:
 On Wednesday 31 October 2007 18:41, Nick Piggin wrote:
 On Wednesday 31 October 2007 18:52, Balbir Singh wrote:
 Reported-by: Nick Piggin [EMAIL PROTECTED]

 The delay incurred in lock_page() should also be accounted in swap delay
 accounting

 Signed-off-by: Balbir Singh [EMAIL PROTECTED]
 Ah right, I forgot to resend this one, sorry. Thanks for remembering.
 
 Although, I think I had a bit more detail in the changelog which
 I think should be kept.
 
 Basically, swap delay accounting seems quite broken as of now,
 because what it is counting is the time required to allocate a new
 page and submit the IO, but not actually the time to perform the IO
 at all (which I'd expect will be significant, although possibly in
 some workloads the actual page allocation will dominate).
 

This looks quite good to me. I'm off attending a wedding, I'll resend
the patch when I am back.

-- 
Warm Regards,
Balbir Singh
Linux Technology Center
IBM, ISTL
-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/