Re: [PATCH 5.4 024/138] dm mpath: pass IO start time to path selector
From: Gabriel Krisman Bertazi
Date: Mon Jul 27 2020 - 12:34:46 EST
Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> writes:
> From: Gabriel Krisman Bertazi <krisman@xxxxxxxxxxxxx>
> [ Upstream commit 087615bf3acdafd0ba7c7c9ed5286e7b7c80fe1b ]
> The HST path selector needs this information to perform path
> prediction. For request-based mpath, struct request's io_start_time_ns
> is used, while for bio-based, use the start_time stored in dm_io.
This patch is not -stable material. It is only needed for a new feature
merged in 5.8.
Gabriel Krisman Bertazi