lkml.org 
[lkml]   [2007]   [Aug]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH] flush icache before set_pte() on ia64 take9 [2/2] flush icache at set_pte
From
From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Date: Thu, 9 Aug 2007 13:57:21 +0900

> Changelog v8 -> v9.
> - removed sync_icache_dcache().
> - modified set_pte() rather than adding new complexed macro.
>
> Old stories
> - For synching icache and dcache before set_pte(), I added a new macro for
> ia64, sync_icache_dcache(). I inserted it in proper places.
> Comments from reviewer was negative becasue ia64 specific codes are
> scattered over vm codes and it will not be able to be maintained.
> An advice was hide all in set_pte() because flush_xxx_cache cannot pass
> enough information to arch.
>
> Current ia64 kernel flushes icache by lazy_mmu_prot_update() *after*
> set_pte(). This is too late. This patch removes lazy_mmu_prot_update and
> add modfied set_pte() for flushing if necessary.
>
> This patch flush icache of a page when
> new pte has exec bit.
> && new pte has present bit
> && new pte is user's page.
> && (old *ptep is not present
> || new pte's pfn is not same to old *ptep's ptn)
> && new pte's page has no Pg_arch_1 bit.
> Pg_arch_1 is set when a page is cache consistent.
>
> I think this condition checks are much easier to understand than considering
> "Where sync_icache_dcache() should be inserted ?".
>
> pte_user() for ia64 was removed by http://lkml.org/lkml/2007/6/12/67 as
> clean-up. So, I added it again.
>
> Signed-Off-By: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>

If this patch works I am very happy with it, since lazy_mmu_prot_update()
is now completely gone as a result.

Acked-by: David S. Miller <davem@davemloft.net>
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2007-08-09 07:13    [W:1.530 / U:0.104 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site