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From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Andrew Morton <akpm@osdl.org>
Cc: Mike Waychison <mikew@google.com>,
	linux-mm@kvack.org,
	Linux Kernel list <linux-kernel@vger.kernel.org>,
	Linus Torvalds <torvalds@osdl.org>
Subject: Re: [RFC] page fault retry with NOPAGE_RETRY
Date: Fri, 22 Sep 2006 08:05:04 +1000	[thread overview]
Message-ID: <1158876304.26347.129.camel@localhost.localdomain> (raw)
In-Reply-To: <20060920105317.7c3eb5f4.akpm@osdl.org>

> So I think there's a nasty DoS here if we permit infinite retries.  But
> it's not just that - there might be other situations under really heavy
> memory pressure where livelocks like this can occur.  It's just a general
> robustness-of-implementation issue.

Got it. Now, changing args to no_page() will be a pretty big task....

Ben.



WARNING: multiple messages have this Message-ID (diff)
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Andrew Morton <akpm@osdl.org>
Cc: Mike Waychison <mikew@google.com>,
	linux-mm@kvack.org,
	Linux Kernel list <linux-kernel@vger.kernel.org>,
	Linus Torvalds <torvalds@osdl.org>
Subject: Re: [RFC] page fault retry with NOPAGE_RETRY
Date: Fri, 22 Sep 2006 08:05:04 +1000	[thread overview]
Message-ID: <1158876304.26347.129.camel@localhost.localdomain> (raw)
In-Reply-To: <20060920105317.7c3eb5f4.akpm@osdl.org>

> So I think there's a nasty DoS here if we permit infinite retries.  But
> it's not just that - there might be other situations under really heavy
> memory pressure where livelocks like this can occur.  It's just a general
> robustness-of-implementation issue.

Got it. Now, changing args to no_page() will be a pretty big task....

Ben.


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  reply	other threads:[~2006-09-21 22:05 UTC|newest]

Thread overview: 55+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-09-14 22:55 [RFC] page fault retry with NOPAGE_RETRY Benjamin Herrenschmidt
2006-09-14 22:55 ` Benjamin Herrenschmidt
2006-09-15  0:19 ` Linus Torvalds
2006-09-15  0:19   ` Linus Torvalds
2006-09-15  7:11 ` Andrew Morton
2006-09-15  7:11   ` Andrew Morton
2006-09-15  7:35   ` Andrew Morton
2006-09-15  7:35     ` Andrew Morton
2006-09-15 13:30     ` Hugh Dickins
2006-09-15 13:30       ` Hugh Dickins
2006-09-16  1:03       ` Benjamin Herrenschmidt
2006-09-16  1:03         ` Benjamin Herrenschmidt
2006-09-19 23:35   ` Mike Waychison
2006-09-19 23:50     ` Benjamin Herrenschmidt
2006-09-19 23:50       ` Benjamin Herrenschmidt
2006-09-19 23:59       ` Andrew Morton
2006-09-19 23:59         ` Andrew Morton
2006-09-20  0:06         ` Benjamin Herrenschmidt
2006-09-20  0:06           ` Benjamin Herrenschmidt
2006-09-20  0:05       ` Benjamin Herrenschmidt
2006-09-20  0:05         ` Benjamin Herrenschmidt
2006-09-20  0:21         ` Andrew Morton
2006-09-20  0:21           ` Andrew Morton
2006-09-20  1:57           ` Benjamin Herrenschmidt
2006-09-20  1:57             ` Benjamin Herrenschmidt
2006-09-20  3:05             ` Andrew Morton
2006-09-20  3:05               ` Andrew Morton
2006-09-20  5:04               ` Benjamin Herrenschmidt
2006-09-20  5:04                 ` Benjamin Herrenschmidt
2006-09-20  5:26                 ` Andrew Morton
2006-09-20  5:26                   ` Andrew Morton
2006-09-20  6:54                   ` Benjamin Herrenschmidt
2006-09-20  6:54                     ` Benjamin Herrenschmidt
2006-09-20 17:53                     ` Andrew Morton
2006-09-20 17:53                       ` Andrew Morton
2006-09-21 22:05                       ` Benjamin Herrenschmidt [this message]
2006-09-21 22:05                         ` Benjamin Herrenschmidt
2006-09-21 22:41                         ` Andrew Morton
2006-09-21 22:41                           ` Andrew Morton
2006-09-21 23:09                           ` Benjamin Herrenschmidt
2006-09-21 23:09                             ` Benjamin Herrenschmidt
2006-09-23 14:21                       ` Hugh Dickins
2006-09-23 14:21                         ` Hugh Dickins
2006-09-23 19:46                         ` Andrew Morton
2006-09-23 19:46                           ` Andrew Morton
2006-09-23 22:35                           ` Benjamin Herrenschmidt
2006-09-23 22:35                             ` Benjamin Herrenschmidt
2006-09-20  5:06               ` Benjamin Herrenschmidt
2006-09-20  5:06                 ` Benjamin Herrenschmidt
2006-09-20  1:14       ` Mike Waychison
2006-09-20  1:14         ` Mike Waychison
2006-09-20  2:02         ` Benjamin Herrenschmidt
2006-09-20  2:02           ` Benjamin Herrenschmidt
2006-09-15 21:35 ` Arnd Bergmann
2006-09-15 21:35   ` Arnd Bergmann

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