Re: [PATCH v3 7/7] zram: writeback throttle

From: Sergey Senozhatsky
Date: Sun Dec 02 2018 - 21:30:55 EST


On (12/03/18 08:18), Minchan Kim wrote:
>
> Per andrew's comment:
> https://lkml.org/lkml/2018/11/27/156
>
> I need to fix it to represent 4K always.

Aha.

Then we need to increase bd_writes PAGE_SIZE/4K times in writeback_store()?

wb_count = atomic64_inc_return(&zram->stats.bd_writes);
...
if (wb_limit != 0 && wb_count >= wb_limit)
zram->stop_writeback = true;

bd_wb_limit is in 4K units; but in writeback_store() we alloc a full page
and write it to the backing device. So the actual number of written bytes
can be larger on systems with page_size > 4K. Right?

-ss