Re: [PATCH 10/10] fs: make aio plug

[Jens Axboe <jaxboe@fusionio.com>]

On 2011-01-24 18:59, Jeff Moyer wrote:
> Jens Axboe <jaxboe@fusionio.com> writes:
> 
>> From: Shaohua Li <shaohua.li@intel.com>
>>
>> Signed-off-by: Shaohua Li <shaohua.li@intel.com>
>> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
>> ---
>>  fs/aio.c |    4 ++++
>>  1 files changed, 4 insertions(+), 0 deletions(-)
>>
>> diff --git a/fs/aio.c b/fs/aio.c
>> index c5ea494..1476bed 100644
>> --- a/fs/aio.c
>> +++ b/fs/aio.c
>> @@ -1660,6 +1660,7 @@ long do_io_submit(aio_context_t ctx_id, long nr,
>>  	long ret = 0;
>>  	int i;
>>  	struct hlist_head batch_hash[AIO_BATCH_HASH_SIZE] = { { 0, }, };
>> +	struct blk_plug plug;
>>  
>>  	if (unlikely(nr < 0))
>>  		return -EINVAL;
>> @@ -1676,6 +1677,8 @@ long do_io_submit(aio_context_t ctx_id, long nr,
>>  		return -EINVAL;
>>  	}
>>  
>> +	blk_start_plug(&plug);
>> +
>>  	/*
>>  	 * AKPM: should this return a partial result if some of the IOs were
>>  	 * successfully submitted?
>> @@ -1698,6 +1701,7 @@ long do_io_submit(aio_context_t ctx_id, long nr,
>>  		if (ret)
>>  			break;
>>  	}
>> +	blk_finish_plug(&plug);
>>  	aio_batch_free(batch_hash);
> 
> I'm pretty sure you want blk_finish_plug to run after aio_batch_free.

You mean to cover the iput()? That's not a bad idea, if that ends up
writing it out. I did a few read tests here and confirmed it's sending
down batches of whatever number is submitted.

-- 
Jens Axboe