Hi Sergey and Joonsoo,
On Wed, Apr 26, 2017 at 02:57:03PM +0900, Joonsoo Kim wrote:
> On Wed, Apr 26, 2017 at 11:14:52AM +0900, Sergey Senozhatsky wrote:
> > Hello,
> >
> > On (04/26/17 09:52), js1...@gmail.com wrote:
> > [..]
> > > ret = scnprintf(buf, PAGE_SIZE,
> > > - "%8llu %8llu %8llu %8lu %8ld %8llu %8lu\n",
> > > + "%8llu %8llu %8llu %8lu %8ld %8llu %8lu %8llu %8llu\n",
> > > orig_size << PAGE_SHIFT,
> > > (u64)atomic64_read(&zram->stats.compr_data_size),
> > > mem_used << PAGE_SHIFT,
> > > zram->limit_pages << PAGE_SHIFT,
> > > max_used << PAGE_SHIFT,
> > > (u64)atomic64_read(&zram->stats.same_pages),
> > > - pool_stats.pages_compacted);
> > > + pool_stats.pages_compacted,
> > > + zram_dedup_dup_size(zram),
> > > + zram_dedup_meta_size(zram));
> >
> > hm... should't we subtract zram_dedup_dup_size(zram) from
> > ->stats.compr_data_size? we don't use extra memory for dedupped
> > pages. or don't inc ->stats.compr_data_size for dedupped pages?
>
> Hmm... My intention is to keep previous stat as much as possible. User
> can just notice the saving by only checking mem_used.
>
> However, it's also odd that compr_data_size doesn't show actual
> compressed data size.
Actually, I found it for the last review cycle but didn't say that
intentionally. Because it is also odd to me that pages_stored isn't
increased for same_pages so I thought we can fix it all.
I mean:
* normal page
inc pages_stored
inc compr_data_size
* same_page
inc pages_stored
inc same_pages
* dedup_page
inc pages_stored
inc dup_data_size
IOW, pages_stored should be increased for every write IO.
But the concern is we have said in zram.txt
orig_data_size uncompressed size of data stored in this disk.
This excludes same-element-filled pages (same_pages) since
no memory is allocated for them.
So, we might be too late. :-(
What do you think about it?
If anyone doesn't have any objection, I want to correct it all.
Thanks.
