On 08/18/2017 09:13 AM, Shaohua Li wrote: > discard request usually is very big and easily use all bandwidth budget > of a cgroup. discard request size doesn't really mean the size of data > written, so it doesn't make sense to account it into bandwidth budget. > This patch ignores discard requests size. It makes sense to account > discard request into iops budget though.
Some (most) devices to touch media for a discard operation, but the cost tends to be fairly constant and independent of discard size. Would it make sense to just treat it as a constant cost? Zero cost seems wrong. -- Jens Axboe
