Hi Jerome, Sergey On Mon, Jan 09, 2017 at 10:09:20AM -0500, Jerome Marchand wrote: > > > ----- Original Message ----- > > From: "Sergey Senozhatsky" <sergey.senozhatsky@xxxxxxxxx> > > To: "Minchan Kim" <minchan@xxxxxxxxxx> > > Cc: "Jens Axboe" <axboe@xxxxxxxxx>, "Hyeoncheol Lee" <cheol.lee@xxxxxxx>, linux-block@xxxxxxxxxxxxxxx, > > linux-kernel@xxxxxxxxxxxxxxx, "Andrew Morton" <akpm@xxxxxxxxxxxxxxxxxxxx>, "Sergey Senozhatsky" > > <sergey.senozhatsky@xxxxxxxxx>, "Jerome Marchand" <jmarchan@xxxxxxxxxx> > > Sent: Monday, January 9, 2017 3:33:44 PM > > Subject: Re: [RFC] blk: increase logical_block_size to unsigned int Remove Robert's mail. It didn't work and don't know his update mail > > > > On (01/09/17 14:04), Minchan Kim wrote: > > > Mostly, zram is used as swap system on embedded world so it want to do IO > > > as PAGE_SIZE aligned/size IO unit. For that, one of the problem was > > > blk_queue_logical_block_size(zram->disk->queue, PAGE_SIZE) made overflow > > > in *64K page system* so [1] changed it to constant 4096. > > > Since that, partial IO can happen so zram should handle it which makes zram > > > complicated[2]. > > > > > > > I thought that zram partial IO support is there because some file > > systems cannot cope with large logical_block_size. like FAT, for > > example. am I wrong? > > Yes indeed. When we discussed the patch adding the partial I/O, increasing the > size of logical_block was considered. The reason we didn't go the easy path was > that not all block users could handle 64k blocks. FAT is one of them. I thought it might make some FSes which doesn't support 64K block but I didn't know what FSes exactly. I thought most popular FSes in linux may work well(e.g., ext, btrfs, xfs). Thanks for the pointer. I guess there might be more as well as FAT so let's keep it. Thanks, Sergey and Jerome! -- To unsubscribe from this list: send the line "unsubscribe linux-block" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
