On Mon, Sep 17, 2018 at 7:10 PM Um, Taeil <taeilum@xxxxxxxxxx> wrote: > > Currently, we allocate PAGE_SIZE * 2 for zswap_dstmem which is used as compression destination buffer. > > However, we pass only half of the size (PAGE_SIZE) to crypto_comp_compress. > > This might not be a problem for CPU based existing lzo, lz4 crypto compression driver implantation. > > However, this could be a problem for some H/W acceleration compression drivers, which honor destination buffer size when it prepares H/W resources. How exactly could it be a problem? > > Actually, this patch is aligned with what zram is passing when it calls crypto_comp_compress. > > The following simple patch will solve this problem. I tested it with existing crypto/lzo.c and crypto/lz4.c compression driver and it works fine. > > > > > > --- mm/zswap.c.orig 2018-09-14 14:36:37.984199232 -0700 > > +++ mm/zswap.c 2018-09-14 14:36:53.340189681 -0700 > > @@ -1001,7 +1001,7 @@ static int zswap_frontswap_store(unsigne > > struct zswap_entry *entry, *dupentry; > > struct crypto_comp *tfm; > > int ret; > > - unsigned int hlen, dlen = PAGE_SIZE; > > + unsigned int hlen, dlen = PAGE_SIZE * 2; > > unsigned long handle, value; > > char *buf; > > u8 *src, *dst; > > > > > > > > Thank you, > > Taeil > >
