On Tue, 27 Nov 2018 11:07:54 +0900 Minchan Kim <minc...@kernel.org> wrote:
> On Mon, Nov 26, 2018 at 12:58:33PM -0800, Andrew Morton wrote: > > On Mon, 26 Nov 2018 17:28:12 +0900 Minchan Kim <minc...@kernel.org> wrote: > > > > > +File /sys/block/zram<id>/bd_stat > > > + > > > +The stat file represents device's backing device statistics. It consists > > > of > > > +a single line of text and contains the following stats separated by > > > whitespace: > > > + bd_count size of data written in backing device. > > > + Unit: pages > > > + bd_reads the number of reads from backing device > > > + Unit: pages > > > + bd_writes the number of writes to backing device > > > + Unit: pages > > > > Using `pages' is a bad choice. And I assume this means that > > writeback_limit is in pages as well, which is worse. > > > > Page sizes are not constant! We want userspace which was developed on > > 4k pagesize to work the same on 64k pagesize. > > > > Arguably, we could require that well-written userspace remember to use > > getpagesize(). However we have traditionally tried to avoid that by > > performing the pagesize normalization within the kernel. > > zram works based on page so I used that term but I agree it's rather > vague. If there is no objection, I will use (Unit: 4K) instead of > (Unit: pages). Is that still true if PAGE_SIZE=64k?
