linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: Manfred Spraul <manfreds@colorfullife.com>
To: "Stephen C. Tweedie" <sct@redhat.com>
Cc: "David S. Miller" <davem@redhat.com>,
	alan@lxorguk.ukuu.org.uk, kanoj@google.engr.sgi.com,
	linux-kernel@vger.rutgers.edu, linux-mm@kvack.org,
	torvalds@transmeta.com
Subject: Re: zap_page_range(): TLB flush race
Date: Tue, 11 Apr 2000 16:41:38 +0200	[thread overview]
Message-ID: <38F339A2.FB3F1699@colorfullife.com> (raw)
In-Reply-To: <20000411101418.E2740@redhat.com>

"Stephen C. Tweedie" wrote:
> 
> 
> OK, I'm sure there are optimisation issues, but I was worried about
> correctness problems from what Alan said.
> 

They are correctness problems:
[I'm only reading the asm source, I might be wrong]

* s390 has hardware support for tlb flush ipis.
* it doesn't support hardware contexts (address space numbers, region
id,...)
* They need the old pte value and the virtual address for their flush
ipi.

-->
	set_pte()
	flush_tlb_page()
doesn't work.

Obviously their work-around
	flush_tlb_page()
	set_pte()
is wrong as well, and it breaks all other architectures :-/

They need an atomic set_and_flush_pte() macro.
OTHO on i386 a tlb flush during set_pte() would cause a dramatic
slowdown.

--
	Manfred
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux.eu.org/Linux-MM/

  reply	other threads:[~2000-04-11 14:41 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2000-04-08 20:06 Manfred Spraul
2000-04-08 21:11 ` Kanoj Sarcar
2000-04-08 22:46   ` Manfred Spraul
2000-04-08 23:31     ` Kanoj Sarcar
2000-04-08 23:37       ` Alan Cox
2000-04-08 23:54         ` Kanoj Sarcar
2000-04-09  9:10         ` Manfred Spraul
2000-04-09  9:19           ` David S. Miller
2000-04-10 22:21         ` Stephen C. Tweedie
2000-04-10 23:12           ` David S. Miller
2000-04-11  9:14             ` Stephen C. Tweedie
2000-04-11 14:41               ` Manfred Spraul [this message]
2000-04-11 16:40                 ` Andrea Arcangeli
2000-04-11 17:45                   ` Manfred Spraul
2000-04-11 18:14                     ` Kanoj Sarcar
2000-04-12 10:02                     ` Jamie Lokier
2000-04-11 11:56           ` Alan Cox
2000-04-08 23:44   ` David S. Miller
2000-04-09  0:20     ` Kanoj Sarcar

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=38F339A2.FB3F1699@colorfullife.com \
    --to=manfreds@colorfullife.com \
    --cc=alan@lxorguk.ukuu.org.uk \
    --cc=davem@redhat.com \
    --cc=kanoj@google.engr.sgi.com \
    --cc=linux-kernel@vger.rutgers.edu \
    --cc=linux-mm@kvack.org \
    --cc=sct@redhat.com \
    --cc=torvalds@transmeta.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox