Thanks Sergey, On Mon, Aug 8, 2022 at 9:38 PM Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx> wrote: > > On (22/08/08 12:50), Brian Geffon wrote: > [..] > > > > pr_info("setup backing device %s\n", file_name); > > @@ -722,7 +707,8 @@ static ssize_t writeback_store(struct device *dev, > > > > if (zram_test_flag(zram, index, ZRAM_WB) || > > zram_test_flag(zram, index, ZRAM_SAME) || > > - zram_test_flag(zram, index, ZRAM_UNDER_WB)) > > + zram_test_flag(zram, index, ZRAM_UNDER_WB) || > > + zram_test_flag(zram, index, ZRAM_NO_WB)) > > goto next; > > mark_idle() probably should also test ZRAM_NO_WB bit. While we definitely can add that check in mark_idle() it actually doesn't hurt to allow marking the page as idle as NO_WB only controls the writeback aspect and as long as the page is marked NO_WB it won't be written back, idle or not. Definitely happy to add it in later versions if people like this approach in general.