zram: move zram size warning to documentation

Move zram warning about disksize and size of memory correlation to zram
documentation.

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Sergey Senozhatsky 2014-04-07 15:38:07 -07:00 committed by Linus Torvalds
parent 59fc86a492
commit e64cd51d2f
2 changed files with 5 additions and 15 deletions

View file

@ -33,6 +33,11 @@ Following shows a typical sequence of steps for using zram.
echo 512M > /sys/block/zram0/disksize
echo 1G > /sys/block/zram0/disksize
Note:
There is little point creating a zram of greater than twice the size of memory
since we expect a 2:1 compression ratio. Note that zram uses about 0.1% of the
size of the disk when not in use so a huge zram is wasteful.
3) Activate:
mkswap /dev/zram0
swapon /dev/zram0

View file

@ -535,23 +535,8 @@ static void zram_reset_device(struct zram *zram, bool reset_capacity)
static void zram_init_device(struct zram *zram, struct zram_meta *meta)
{
if (zram->disksize > 2 * (totalram_pages << PAGE_SHIFT)) {
pr_info(
"There is little point creating a zram of greater than "
"twice the size of memory since we expect a 2:1 compression "
"ratio. Note that zram uses about 0.1%% of the size of "
"the disk when not in use so a huge zram is "
"wasteful.\n"
"\tMemory Size: %lu kB\n"
"\tSize you selected: %llu kB\n"
"Continuing anyway ...\n",
(totalram_pages << PAGE_SHIFT) >> 10, zram->disksize >> 10
);
}
/* zram devices sort of resembles non-rotational disks */
queue_flag_set_unlocked(QUEUE_FLAG_NONROT, zram->disk->queue);
zram->meta = meta;
pr_debug("Initialization done!\n");
}