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Date: Thu, 14 Apr 2022 17:42:25 +0000
From: Hao Lee <haolee.swjtu@gmail.com>
Subject: The answer of Quiz C.8 is not quite reasonable
Message-ID: <20220414174225.GA29861@haolee.io>
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To: paulmck@kernel.org
Cc: perfbook@vger.kernel.org
List-ID: <perfbook.vger.kernel.org>

Hi,

At the beginning of C.3.3 we have supposed the cache line containing "a"
resides _only_ in _CPU1’s_ cache. I think this is why _CPU0_ has to send
a "_read_ invalidate message" to _retrieve_ the cache line and invalid
CPU1's cache line.

However, the answer says the reason is the cache line in question
contains more than just the variable a. I can't understand the logical
relationship between this answer and the question. Am I missing
something here? Thanks.

Regards,
Hao Lee