Hi Greg, I added all Acked-by and rebased on next-20130202. Please apply this.
On Mon, Feb 04, 2013 at 08:46:08AM +0900, Minchan Kim wrote: > Now zram allocates new page with GFP_KERNEL in zram I/O path > if IO is partial. Unfortunately, It may cause deadlock with > reclaim path like below. > > write_page from fs > fs_lock > allocation(GFP_KERNEL) > reclaim > pageout > write_page from fs > fs_lock <-- deadlock > > This patch fixes it by using GFP_NOIO. In read path, we > reorganize code flow so that kmap_atomic is called after the > GFP_NOIO allocation. > > Cc: [email protected] > Acked-by: Jerome Marchand <[email protected]> > Acked-by: Nitin Gupta <[email protected]> > [ [email protected]: don't use GFP_ATOMIC ] > Signed-off-by: Pekka Enberg <[email protected]> > Signed-off-by: Minchan Kim <[email protected]> > --- > drivers/staging/zram/zram_drv.c | 9 +++++---- > 1 file changed, 5 insertions(+), 4 deletions(-) > > diff --git a/drivers/staging/zram/zram_drv.c b/drivers/staging/zram/zram_drv.c > index 941b7c6..262265e 100644 > --- a/drivers/staging/zram/zram_drv.c > +++ b/drivers/staging/zram/zram_drv.c > @@ -217,11 +217,12 @@ static int zram_bvec_read(struct zram *zram, struct > bio_vec *bvec, > return 0; > } > > - user_mem = kmap_atomic(page); > if (is_partial_io(bvec)) > /* Use a temporary buffer to decompress the page */ > - uncmem = kmalloc(PAGE_SIZE, GFP_KERNEL); > - else > + uncmem = kmalloc(PAGE_SIZE, GFP_NOIO); > + > + user_mem = kmap_atomic(page); > + if (!is_partial_io(bvec)) > uncmem = user_mem; > > if (!uncmem) { > @@ -268,7 +269,7 @@ static int zram_bvec_write(struct zram *zram, struct > bio_vec *bvec, u32 index, > * This is a partial IO. We need to read the full page > * before to write the changes. > */ > - uncmem = kmalloc(PAGE_SIZE, GFP_KERNEL); > + uncmem = kmalloc(PAGE_SIZE, GFP_NOIO); > if (!uncmem) { > pr_info("Error allocating temp memory!\n"); > ret = -ENOMEM; > -- > 1.7.9.5 > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to [email protected]. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: <a href=mailto:"[email protected]";> [email protected] </a> -- Kind regards, Minchan Kim -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
