Hi Mika,
On Mon, Apr 03, 2017 at 08:52:33AM +0300, Mika Penttilä wrote:
>
> Hi!
>
> On 04/03/2017 08:17 AM, Minchan Kim wrote:
> > For architecture(PAGE_SIZE > 4K), zram have supported partial IO.
> > However, the mixed code for handling normal/partial IO is too mess,
> > error-prone to modify IO handler functions with upcoming feature
> > so this patch aims for cleaning up zram's IO handling functions.
> >
> > Signed-off-by: Minchan Kim <minc...@kernel.org>
> > ---
> > drivers/block/zram/zram_drv.c | 333
> > +++++++++++++++++++++++-------------------
> > 1 file changed, 184 insertions(+), 149 deletions(-)
> >
> > diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
> > index 28c2836f8c96..7938f4b98b01 100644
> > --- a/drivers/block/zram/zram_drv.c
> > +++ b/drivers/block/zram/zram_drv.c
> > @@ -45,6 +45,8 @@ static const char *default_compressor = "lzo";
> > /* Module params (documentation at end) */
> > static unsigned int num_devices = 1;
> >
> > +static void zram_free_page(struct zram *zram, size_t index);
> > +
> > static inline bool init_done(struct zram *zram)
> > {
> > return zram->disksize;
> > @@ -98,10 +100,17 @@ static void zram_set_obj_size(struct zram_meta *meta,
> > meta->table[index].value = (flags << ZRAM_FLAG_SHIFT) | size;
> > }
> >
> > +#if PAGE_SIZE != 4096
> > static inline bool is_partial_io(struct bio_vec *bvec)
> > {
> > return bvec->bv_len != PAGE_SIZE;
> > }
> > +#else
>
> For page size of 4096 bv_len can still be < 4096 and partial pages should be
> supported
> (uncompress before write etc). ?
zram declares this.
#define ZRAM_LOGICAL_BLOCK_SIZE (1<<12)
blk_queue_physical_block_size(zram->disk->queue, PAGE_SIZE);
blk_queue_logical_block_size(zram->disk->queue,
ZRAM_LOGICAL_BLOCK_SIZE);
So, I thought there is no such partial IO in 4096 page architecture.
Am I missing something? Could you tell the scenario if it happens?
Thanks!
