Thread (104 messages) 104 messages, 13 authors, 2023-12-05

Re: [PATCH 21/21] nvme: Support atomic writes

From: John Garry <john.g.garry@oracle.com>
Date: 2023-10-05 16:19:04
Also in: linux-block, linux-fsdevel, linux-nvme, linux-xfs, lkml

On 05/10/2023 14:32, Pankaj Raghav wrote:
quoted
quoted
te_unit_[min| max]_sectors expects sectors (512 bytes unit)
as input but no conversion is done here from device logical block size
to SECTORs.
Yeah, you are right. I think that we can just use:

blk_queue_atomic_write_unit_max_sectors(disk->queue,
atomic_bs >> SECTOR_SHIFT);
Makes sense.
I still don't grok the difference between max_bytes and unit_max_sectors here.
(Maybe NVMe spec does not differentiate it?)
I think that max_bytes does not need to be a power-of-2 and could be 
relaxed.

Having said that, max_bytes comes into play for merging of bios - so if 
we are in a scenario with no merging, then may a well leave 
atomic_write_max_bytes == atomic_write_unit_max.

But let us check this proposal to relax.
I assume min_sectors should be as follows instead of setting it to 1 (512 bytes)?

blk_queue_atomic_write_unit_min_sectors(disk->queue, bs >> SECTORS_SHIFT);
Yeah, right, we want unit_min to be the logical block size.

Thanks,
John

Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help