Is there a case for introducing blk_plug in write_one_page() can't
seem to find that support in the code flow
write_one_page()->mpage_writepage()
Regards,
Amit Sahrawat
On Fri, Feb 3, 2012 at 7:31 PM, Amit Sahrawat <amit.sahrawat83@xxxxxxxxx> wrote:
> Hi Peter,
> Thanks for pointing out.
>
> While checking the plug support in Write code flow, I came across this
> main point from which - we invoke
> writepages(mapping->a_ops->writepages(mapping, wbc)) from almost all
> the the filesystems.
>
> By mistake I checked 2 different kernel versions for this code(and
> missed that the current version already has put plug in
> mpage_writepages) ... so may be this patch is not worth considering.
>
> Regards,
> Amit Sahrawat
>
>
> On Fri, Feb 3, 2012 at 7:02 PM, Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> wrote:
>> On Fri, 2012-02-03 at 18:57 +0530, Amit Sahrawat wrote:
>>> This will cover all the invocations for writepages to be called with
>>> plugging support.
>>
>> This changelog fails to explain why this is a good thing... I thought
>> the idea of the new plugging stuff was that we now don't need to
>> sprinkle plugs all over the kernel..
>>
>>> Signed-off-by: Amit Sahrawat <a.sahrawat@xxxxxxxxxxx>
>>> ---
>>> mm/page-writeback.c | 4 ++++
>>> 1 files changed, 4 insertions(+), 0 deletions(-)
>>>
>>> diff --git a/mm/page-writeback.c b/mm/page-writeback.c
>>> index 363ba70..2bea32c 100644
>>> --- a/mm/page-writeback.c
>>> +++ b/mm/page-writeback.c
>>> @@ -1866,14 +1866,18 @@ EXPORT_SYMBOL(generic_writepages);
>>>
>>> int do_writepages(struct address_space *mapping, struct writeback_control *wbc)
>>> {
>>> + struct blk_plug plug;
>>> int ret;
>>>
>>> if (wbc->nr_to_write <= 0)
>>> return 0;
>>> +
>>> + blk_start_plug(&plug);
>>> if (mapping->a_ops->writepages)
>>> ret = mapping->a_ops->writepages(mapping, wbc);
>>> else
>>> ret = generic_writepages(mapping, wbc);
>>> + blk_finish_plug(&plug);
>>> return ret;
>>> }
>>>
>>
>>
>>
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxx. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href