From: Remy Horton <remy.horton@intel.com>
To: Andriy Berestovskyy <aber@semihalf.com>,
"Van Haaren, Harry" <harry.van.haaren@intel.com>
Cc: "dev@dpdk.org" <dev@dpdk.org>
Subject: Re: [dpdk-dev] [PATCH] keepalive: fix keepalive state alignment
Date: Tue, 23 Jan 2018 10:16:54 +0000 [thread overview]
Message-ID: <14e524b4-b844-63ef-b686-6bddf468a464@intel.com> (raw)
In-Reply-To: <CAOysbxoRFMfn2W-ekdtSQ-3xkLwLANt-E4WWupihUh1gwR+TKQ@mail.gmail.com>
On 22/01/2018 18:20, Andriy Berestovskyy wrote:
[..]
> On Fri, Jan 19, 2018 at 6:31 PM, Van Haaren, Harry
> <harry.van.haaren@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
next prev parent reply other threads:[~2018-01-23 10:16 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-19 14:47 Andriy Berestovskyy
2018-01-19 17:31 ` Van Haaren, Harry
2018-01-22 18:20 ` Andriy Berestovskyy
2018-01-23 10:16 ` Remy Horton [this message]
2018-01-23 10:27 ` Van Haaren, Harry
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