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From: heechul@illinois.edu (heechul Yun)
To: linux-arm-kernel@lists.infradead.org
Subject: Unnecessary cache-line flush on page table updates ?
Date: Fri, 1 Jul 2011 00:04:42 -0700	[thread overview]
Message-ID: <BANLkTin7aJXjpEH_WzJi5zaAtH8kFcTZeg@mail.gmail.com> (raw)

Catalin,

Based on TRM of Cortex A9, the MMU reads page table entries from L1-D
cache not from memory. Then I think we do not need to flush the cache
line in the following code because MMU will always see up-to-date view
of page table in both UP and SMP systems.

linux/arch/arm/mm/proc-v7.S

ENTRY(cpu_v7_set_pte_ext)
	...
        mcr     p15, 0, r0, c7, c10, 1          @ flush_pte from
D-cache // why we need this in A9?
        ?

If this is a necessary one, could you please explain the reason? Thanks.

             reply	other threads:[~2011-07-01  7:04 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-07-01  7:04 heechul Yun [this message]
2011-07-01 10:10 ` Unnecessary cache-line flush on page table updates ? Catalin Marinas
2011-07-01 21:42   ` heechul Yun
2011-07-04  9:45     ` Catalin Marinas
2011-07-04 10:02       ` Russell King - ARM Linux
2011-07-04 10:43         ` Catalin Marinas
2011-07-04 11:13           ` Russell King - ARM Linux
2011-07-04 15:58             ` Catalin Marinas
2011-07-04 19:58               ` Russell King - ARM Linux
2011-07-04 23:20                 ` Russell King - ARM Linux
2011-07-06 16:05                   ` Catalin Marinas
2011-07-06 18:08                     ` Russell King - ARM Linux
2011-07-11 16:49                       ` Catalin Marinas
2011-07-11 17:01                         ` Russell King - ARM Linux
2011-07-12 13:09                           ` Catalin Marinas
2011-07-15 16:24                             ` Russell King - ARM Linux
2011-07-05 10:07                 ` Catalin Marinas
2011-07-04 21:55             ` Russell King - ARM Linux
2011-07-05  9:26               ` Catalin Marinas
2011-07-05  9:46                 ` Russell King - ARM Linux
2011-07-06 15:52                   ` Catalin Marinas
2011-07-06 15:55                     ` Russell King - ARM Linux
2011-07-06 16:15                       ` Catalin Marinas
2011-07-05 10:48                 ` Russell King - ARM Linux
2011-07-05 13:54                   ` Catalin Marinas
2011-07-05 14:15                     ` Russell King - ARM Linux
2011-07-05 14:40                       ` Catalin Marinas
2011-07-04 13:05           ` Russell King - ARM Linux
2011-07-04 13:15             ` Catalin Marinas
2011-07-04 14:59       ` heechul Yun
2011-07-04 21:24     ` heechul Yun

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