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From: Richard Henderson <rth@twiddle.net>
To: Paul Mackerras <paulus@samba.org>
Cc: David Mosberger <davidm@hpl.hp.com>,
	torvalds@transmeta.com, linux-kernel@vger.kernel.org,
	davem@redhat.com
Subject: Re: [PATCH] avoid unnecessary cache flushes
Date: Tue, 4 Sep 2001 09:44:12 -0700	[thread overview]
Message-ID: <20010904094412.B18163@twiddle.net> (raw)
In-Reply-To: <15247.29338.3671.548678@cargo.ozlabs.ibm.com> <20010903131436.A16069@twiddle.net> <15251.59286.154267.431231@napali.hpl.hp.com> <20010903134125.B16069@twiddle.net> <15252.13330.652765.959658@cargo.ozlabs.ibm.com>
In-Reply-To: <15252.13330.652765.959658@cargo.ozlabs.ibm.com>; from paulus@samba.org on Tue, Sep 04, 2001 at 11:53:22AM +1000

On Tue, Sep 04, 2001 at 11:53:22AM +1000, Paul Mackerras wrote:
> If the page is a private page (private COW or anonymous page) then I
> don't see where the kernel would be modifying the page.

ptrace set breakpoint?

> For alpha, the thing that my patch does that might hurt is the change
> from flush_icache_page to flush_icache_range in kernel/ptrace.c.  Any
> comment on that?

Hum.  Yes.  We need a way to distinguish between userspace and
kernelspace icache flushes.

Previously, flush_icache_page was used exclusively for userspace
and flush_icache_range exclusively for kernelspace.  Since I _do_
have address space numbers, I can avoid the "flush all" by allocating
a new ASN for the user process.  Which doesn't work for the kernel
of course; there I do have to flush all.


r~

      parent reply	other threads:[~2001-09-04 16:44 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2001-08-31 11:18 [PATCH] avoid unnecessary cache flushes Paul Mackerras
2001-08-31 22:45 ` David S. Miller
2001-09-01  8:35   ` Paul Mackerras
2001-09-01  8:55     ` David S. Miller
2001-09-01 11:47       ` Paul Mackerras
2001-09-01 12:24         ` David S. Miller
2001-09-03 20:14 ` Richard Henderson
2001-09-03 20:27   ` David Mosberger
2001-09-03 20:41     ` Richard Henderson
2001-09-03 21:00       ` David Mosberger
2001-09-04 16:37         ` Richard Henderson
2001-09-04 17:06           ` David Mosberger
2001-09-04  1:53       ` Paul Mackerras
2001-09-04  2:31         ` Andrea Arcangeli
2001-09-04  4:08           ` Paul Mackerras
2001-09-04 12:58             ` Andrea Arcangeli
2001-09-04 16:44         ` Richard Henderson [this message]

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