Hello Karam,
On Mon, Oct 06, 2014 at 02:31:05PM +0900, karam....@lge.com wrote:
> From: "karam.lee" <karam....@lge.com>
>
> Recently rw_page block device operation is added.
> This patch implements rw_page operation for zram block device so
> zram can process page sized I/O without bio.
It's a performance enhance patch? If you had, pz, inclulde the result
in the description.
> ---
> ---
> drivers/block/zram/zram_drv.c | 60
> +++++++++++++++++++++++++++++++++++------
> 1 file changed, 52 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
> index 48eccb3..b76a5dc 100644
> --- a/drivers/block/zram/zram_drv.c
> +++ b/drivers/block/zram/zram_drv.c
> @@ -368,7 +368,7 @@ static int zram_decompress_page(struct zram *zram, char
> *mem, u32 index)
> }
>
> static int zram_bvec_read(struct zram *zram, struct bio_vec *bvec,
> - u32 index, int offset, struct bio *bio)
> + u32 index, int offset)
Isn't it cleanup? Please, separate it into another patch.
> {
> int ret;
> struct page *page;
> @@ -535,14 +535,13 @@ out:
> }
>
> static int zram_bvec_rw(struct zram *zram, struct bio_vec *bvec, u32 index,
> - int offset, struct bio *bio)
> + int offset, int rw)
> {
> int ret;
> - int rw = bio_data_dir(bio);
>
> if (rw == READ) {
> atomic64_inc(&zram->stats.num_reads);
> - ret = zram_bvec_read(zram, bvec, index, offset, bio);
> + ret = zram_bvec_read(zram, bvec, index, offset);
> } else {
> atomic64_inc(&zram->stats.num_writes);
> ret = zram_bvec_write(zram, bvec, index, offset);
> @@ -718,7 +717,7 @@ out:
>
> static void __zram_make_request(struct zram *zram, struct bio *bio)
> {
> - int offset;
> + int offset, rw;
> u32 index;
> struct bio_vec bvec;
> struct bvec_iter iter;
> @@ -733,6 +732,7 @@ static void __zram_make_request(struct zram *zram, struct
> bio *bio)
> return;
> }
>
> + rw = bio_data_dir(bio);
> bio_for_each_segment(bvec, bio, iter) {
> int max_transfer_size = PAGE_SIZE - offset;
>
> @@ -747,15 +747,15 @@ static void __zram_make_request(struct zram *zram,
> struct bio *bio)
> bv.bv_len = max_transfer_size;
> bv.bv_offset = bvec.bv_offset;
>
> - if (zram_bvec_rw(zram, &bv, index, offset, bio) < 0)
> + if (zram_bvec_rw(zram, &bv, index, offset, rw) < 0)
> goto out;
>
> bv.bv_len = bvec.bv_len - max_transfer_size;
> bv.bv_offset += max_transfer_size;
> - if (zram_bvec_rw(zram, &bv, index + 1, 0, bio) < 0)
> + if (zram_bvec_rw(zram, &bv, index + 1, 0, rw) < 0)
> goto out;
> } else
> - if (zram_bvec_rw(zram, &bvec, index, offset, bio) < 0)
> + if (zram_bvec_rw(zram, &bvec, index, offset, rw) < 0)
> goto out;
>
> update_position(&index, &offset, &bvec);
> @@ -810,8 +810,52 @@ static void zram_slot_free_notify(struct block_device
> *bdev,
> atomic64_inc(&zram->stats.notify_free);
> }
>
> +static int zram_rw_page(struct block_device *bdev, sector_t sector,
> + struct page *page, int rw)
> +{
> + int offset, ret = 1;
> + u32 index;
> + u64 start, end, bound;
> + struct zram *zram;
> + struct bio_vec bv;
> +
> + zram = bdev->bd_disk->private_data;
> +
> + if (unlikely(sector&
> + (ZRAM_SECTOR_PER_LOGICAL_BLOCK - 1)))
> + goto out;
> +
> + start = sector;
> + end = start + (PAGE_SIZE >> SECTOR_SHIFT);
> + bound = zram->disksize >> SECTOR_SHIFT;
> + if (unlikely(start >= bound || end > bound || start > end))
> + goto out;
Please modify valid_io_request to used for your purpose and share it
with zram_make_request.
And please include Jerome because I'd like to confirm this patch in
partial_io system for just in case.
> +
> + down_read(&zram->init_lock);
> + if (unlikely(!init_done(zram))) {
> + ret = -ENOMEM;
> + goto out_unlock;
> + }
> +
> + index = sector >> SECTORS_PER_PAGE_SHIFT;
> + offset = sector & (SECTORS_PER_PAGE - 1) << SECTOR_SHIFT;
> +
> + bv.bv_page = page;
> + bv.bv_len = PAGE_SIZE;
> + bv.bv_offset = 0;
> +
> + ret = zram_bvec_rw(zram, &bv, index, offset, rw);
> + page_endio(page, rw, ret);
> +
> +out_unlock:
> + up_read(&zram->init_lock);
> +out:
> + return ret;
> +}
> +
> static const struct block_device_operations zram_devops = {
> .swap_slot_free_notify = zram_slot_free_notify,
> + .rw_page = zram_rw_page,
> .owner = THIS_MODULE
> };
>
> --
> 1.7.9.5
>
> --
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--
Kind regards,
Minchan Kim
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