From: Benjamin Herrenschmidt <benh@kernel•crashing.org>
To: Juergen Kienhoefer <juergen@kienhoefer•com>
Cc: linuxppc-dev list <linuxppc-dev@lists•linuxppc.org>
Subject: Re: cache coherence problem
Date: Tue, 18 Nov 2003 16:22:35 +1100 [thread overview]
Message-ID: <1069132955.7170.120.camel@gaston> (raw)
In-Reply-To: <3FB9A77C.3030101@kienhoefer.com>
On Tue, 2003-11-18 at 16:00, Juergen Kienhoefer wrote:
> Guys,
> Thank you very much for the ideas.
> Basically, what I need to do is:
> dcbst
> sync
> iccci
^^^^^^^
No: icbi
> sync
> isync
> for every 32 bytes of the memory block I put code in.
> Right?
> Cheers
> Juergen
>
>
> Benjamin Herrenschmidt wrote:
>
> >On Tue, 2003-11-18 at 12:16, Juergen Kienhoefer wrote:
> >
> >
> >>Guys,
> >>Look at the folloging test program. It mmaps memory, puts some
> >>instructions in it and executes it.
> >>Sometimes it works, sometimes it crashes with illegal instruction.
> >>This smells like cache problems.
> >>Should the kernel clean the instruction cache for these addresses
> >>in mmap system call?
> >>Thanks for any thoughts!
> >>Juergen
> >>
> >>
> >
> >It's your duty to ensure cache coherency. Actually, the kernel
> >will eventually clean the icache for newly mapped in blank pages,
> >but it will certainly not enforce flush of your writes to memory.
> >
> >You need to first flush the data cache to memory using dcbf or
> >dcbst, then sync for this to complete, then invalidate the
> >instruction cache, sync and isync.
> >
> >Ben.
> >
> >
> >
>
>
** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/
next prev parent reply other threads:[~2003-11-18 5:22 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-11-18 1:16 cache coherence problem Juergen Kienhoefer
2003-11-18 2:36 ` Matt Porter
2003-11-18 2:38 ` Michael R. Zucca
2003-11-19 22:35 ` linas
2003-11-18 3:02 ` Benjamin Herrenschmidt
2003-11-18 5:00 ` Juergen Kienhoefer
2003-11-18 5:22 ` Benjamin Herrenschmidt [this message]
2003-11-18 5:24 ` Benjamin Herrenschmidt
2003-11-18 17:40 ` cache coherence problem: FIXED Juergen Kienhoefer
2003-11-18 8:04 ` cache coherence problem Wolfgang Denk
2003-11-18 9:37 ` Gabriel Paubert
2003-11-19 0:35 ` Benjamin Herrenschmidt
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