> From: Horton, Remy > Sent: Tuesday, January 23, 2018 10:17 AM > To: Andriy Berestovskyy <a...@semihalf.com>; Van Haaren, Harry > <harry.van.haa...@intel.com> > Cc: dev@dpdk.org > Subject: Re: [dpdk-dev] [PATCH] keepalive: fix keepalive state alignment > > > On 22/01/2018 18:20, Andriy Berestovskyy wrote: > [..] > > On Fri, Jan 19, 2018 at 6:31 PM, Van Haaren, Harry > > <harry.van.haa...@intel.com> wrote: > >> These changes do reduce false-sharing however is there actually a > >> performance benefit? A lot of cache space will be taken up if each > >> core requires its own cache line, which will reduce performance > >> again.. it's a tradeoff. > [..] > > 2. The original code (prior e70a61ad50ab "keepalive: export states") > > had each element aligned to the cache line, not the whole array. > > Aligning each flag element was the original intention, so I see no issue > in restoring it. The monitoring core only reads the entries within > state_flags for which the corresponding active_core is set, so > ultimately the trade-off in cache line usage is one made by the > application when it decides which cores need monitoring. > > ..Remy
No objection here - just making sure the change was intentional and the effects are considered. @Remy as you're the Keepalive maintainer I'll leave Acking to you :) -Harry
