>>>>> "Benjamin" == Benjamin Marzinski <bmarzins@xxxxxxxxxx> writes: Benjamin> On Mon, Jan 20, 2020 at 03:20:14PM -0500, John Stoffel wrote: >> >>>>> "Benjamin" == Benjamin Marzinski <bmarzins@xxxxxxxxxx> writes: >> Benjamin> On Sat, Jan 18, 2020 at 12:43:49PM -0500, John Stoffel wrote: >> >> >>>>> "Benjamin" == Benjamin Marzinski <bmarzins@xxxxxxxxxx> writes: >> >> Benjamin> The way that the checkers async mode worked in multipathd didn't make Benjamin> much sense. When multipathd starts up, all checker classes are in the Benjamin> sync mode, and any pathinfo() calls on devices would run the checker in Benjamin> sync mode. However, the First time a checker class was used in Benjamin> checkerloop, it would set that checker class to async (assuming Benjamin> force_sync wasn't set). After that, no matter when a checker from that Benjamin> class was called, it would always run in async mode. Multipathd doesn't Benjamin> need to run checkers in sync mode at all, so don't. >> >> >> >> Sorry, I had a hard time parsing this description, especially the last >> >> sentence. Do you mean that checkers should default to async then, >> >> instead of sync mode? And from looking at the code, don't you mean >> >> that you force sync mode? I guess the question is whether checker >> >> classes should default sync, or async. And if they move to async, >> >> should they stay there? >> >> >> Benjamin> Sorry. I mean that right now multipathd runs the checkers from pathinfo(), Benjamin> wait_for_pending_paths() and check_path(). When multipathd starts, all Benjamin> checkers are in sync mode. The first time a checker is run from Benjamin> check_path(), it is switched to async mode, and stays there for the rest Benjamin> of the time multipathd is runing. >> Benjamin> There is no need for multipathd to run checkers in sync mode at all, so Benjamin> we shouldn't be doing so for these first checks. >> >> Thanks, that makes the entire issue much more clear. This raises the >> question of why there is a sync mode at all then? In any case, the >> above makes the issue more understandable. Benjamin> The multipath command, which uses the same checkers, runs in sync mode. Crystal clean now. Thanks for your patience! -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
