On 2011-05-26 17:18, Boaz Harrosh wrote:
> On 05/26/2011 12:30 AM, Benny Halevy wrote:
>> By default, unless pnfs is used coalesce pages until pg_bsize
>> (rsize or wsize) is reached.
>>
>> pnfs layout drivers define their own pg_test methods that use
>> pnfs_generic_pg_test and need to define their own I/O size
>> limits (e.g. based on the file stripe size).
>>
>> Signed-off-by: Benny Halevy <bhalevy@xxxxxxxxxxx>
>> ---
>> fs/nfs/pagelist.c | 17 +++++++----------
>> 1 files changed, 7 insertions(+), 10 deletions(-)
>>
>> diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
>> index 0209ffb..c795660 100644
>> --- a/fs/nfs/pagelist.c
>> +++ b/fs/nfs/pagelist.c
>> @@ -204,6 +204,11 @@ nfs_wait_on_request(struct nfs_page *req)
>> TASK_UNINTERRUPTIBLE);
>> }
>>
>> +static bool nfs_generic_pg_test(struct nfs_pageio_descriptor *desc, struct nfs_page *prev, struct nfs_page *req)
>> +{
>> + return desc->pg_count + req->wb_bytes <= desc->pg_bsize;
>> +}
>> +
>> /**
>> * nfs_pageio_init - initialise a page io descriptor
>> * @desc: pointer to descriptor
>> @@ -229,7 +234,7 @@ void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
>> desc->pg_ioflags = io_flags;
>> desc->pg_error = 0;
>> desc->pg_lseg = NULL;
>> - desc->pg_test = NULL;
>> + desc->pg_test = nfs_generic_pg_test;
>> }
>>
>> /**
>> @@ -259,13 +264,7 @@ static bool nfs_can_coalesce_requests(struct nfs_page *prev,
>> return false;
>> if (prev->wb_pgbase + prev->wb_bytes != PAGE_CACHE_SIZE)
>> return false;
>> - /*
>> - * Non-whole file layouts need to check that req is inside of
>> - * pgio->pg_lseg.
>> - */
>> - if (pgio->pg_test && !pgio->pg_test(pgio, prev, req))
>> - return false;
>> - return true;
>> + return pgio->pg_test(pgio, prev, req);
>> }
>>
>> /**
>> @@ -294,8 +293,6 @@ static int nfs_pageio_do_add_request(struct nfs_pageio_descriptor *desc,
>> if (desc->pg_bsize < PAGE_SIZE)
>> return 0;
>
> What about this part? what is desc->pg_bsize? Is it not what was negotiated with the
> MDS? this too should be ignored in PNFS. Maybe just add it to the generic test? me think
Agreed.
Benny
>
> Boaz
>
>> newlen += desc->pg_count;
>> - if (newlen > desc->pg_bsize)
>> - return 0;
>> prev = nfs_list_entry(desc->pg_list.prev);
>> if (!nfs_can_coalesce_requests(prev, req, desc))
>> return 0;
>
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