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From: Pavel Machek <pavel@suse.cz>
To: Andrea Arcangeli <andrea@novell.com>
Cc: Rik van Riel <riel@redhat.com>,
	Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	"Martin J. Bligh" <mbligh@aracnet.com>,
	Andrew Morton <akpm@osdl.org>,
	Linux Kernel list <linux-kernel@vger.kernel.org>
Subject: Re: ptep_establish/establish_pte needs set_pte_atomic and all set_pte must be written in asm
Date: Tue, 28 Sep 2004 11:12:52 +0200	[thread overview]
Message-ID: <20040928091252.GD18819@elf.ucw.cz> (raw)
In-Reply-To: <20040926004608.GS3309@dualathlon.random>

Hi!

> > > But even ppc64 is wrong as far as C is concerned,
> > 
> > Looks fine to me.  From include/asm-ppc64/pgtable.h
> > 
> > static inline void set_pte(pte_t *ptep, pte_t pte)
> > {
> >         if (pte_present(*ptep)) {
> >                 pte_clear(ptep);
> >                 flush_tlb_pending();
> >         }
> >         *ptep = __pte(pte_val(pte)) & ~_PAGE_HPTEFLAGS;
> > }
> 
> As far as the C language is concerned that *ptep = something can be
> implemented with 8 writes of 1 byte each (or alternatively with an
> assembler instruction that may make the written data visible not

I'd say that it is okay to do this in arch-dependend
code. Architecture controls list of compilers allowed.


								Pavel
-- 
People were complaining that M$ turns users into beta-testers...
...jr ghea gurz vagb qrirybcref, naq gurl frrz gb yvxr vg gung jnl!

  parent reply	other threads:[~2004-09-28  9:15 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2004-09-25 15:54 ptep_establish/establish_pte needs set_pte_atomic and all set_pte must be written in asm Andrea Arcangeli
2004-09-25 23:33 ` Benjamin Herrenschmidt
2004-09-26  0:20   ` Andrea Arcangeli
2004-09-26  0:31     ` Rik van Riel
2004-09-26  0:46       ` Andrea Arcangeli
2004-09-26  0:59         ` Benjamin Herrenschmidt
2004-09-26  1:36           ` Andrea Arcangeli
2004-09-26  5:31             ` Benjamin Herrenschmidt
2004-09-26 20:30           ` Paul Mackerras
     [not found]             ` <20040926203640.GR2499@dualathlon.random>
2004-09-27 16:41               ` Andrea Arcangeli
2004-09-28  9:12         ` Pavel Machek [this message]
2004-09-26  0:44     ` Benjamin Herrenschmidt
2004-09-26  1:32       ` Andrea Arcangeli
2004-09-26  5:29         ` Benjamin Herrenschmidt
2004-09-26 15:39           ` Andrea Arcangeli
2004-09-26 14:41       ` Martin J. Bligh
2004-09-26 15:41         ` Andrea Arcangeli
2004-09-25 23:44 ` Rik van Riel
2004-09-26  0:31   ` Andrea Arcangeli
2004-09-26  0:37     ` Rik van Riel

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