-
Shaohua Li authored
There are complaints that raid0 discard handling is slow. Currently we divide discard request into chunks and dispatch to underlayer disks. The block layer will do merge to form big requests. This causes a lot of request split/merge and uses significant CPU time. A simple idea is to calculate the range for each raid disk for an IO request and send a discard request to raid disks, which will avoid the split/merge completely. Previously Coly tried the approach, but the implementation was too complex because of raid0 zones. This patch always split bio in zone boundary and handle bio within one zone. It simplifies the implementation a lot. Reviewed-by:
NeilBrown <neilb@suse.com> Acked-by:
Coly Li <colyli@suse.de> Signed-off-by:
Shaohua Li <shli@fb.com>
29efc390