From: kanoj@google.engr.sgi.com (Kanoj Sarcar)
To: Kanoj Sarcar <kanoj@google.engr.sgi.com>
Cc: sct@redhat.com, linux-mm@kvack.org
Subject: Re: filecache/swapcache questions
Date: Mon, 21 Jun 1999 16:44:34 -0700 (PDT) [thread overview]
Message-ID: <199906212344.QAA93017@google.engr.sgi.com> (raw)
In-Reply-To: <199906211846.LAA91751@google.engr.sgi.com> from "Kanoj Sarcar" at Jun 21, 99 11:46:27 am
And continuing on with the problems with swapoff ...
While forking, we copy swap handles from the parent into the child
in copy_page_range. There are of course sleep point in dup_mmap
(kmem_cache_alloc would be one, vm_ops->open could be another).
A swapoff coming in at this point might scan the process list, not
find the nascent child, and just delete the device, leaving the
child referencing the old swap handles.
Irregardless of our current discussions about why the mmap_sem
is needed in swapoff to protect ptes, it seems that grabbing it
in swapoff could trivially solve this fork race ... and some code
changes in exit_mmap could also fix the exit race ...
Kanoj
kanoj@engr.sgi.com
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next prev parent reply other threads:[~1999-06-21 23:44 UTC|newest]
Thread overview: 70+ messages / expand[flat|nested] mbox.gz Atom feed top
1999-06-21 5:29 Kanoj Sarcar
1999-06-21 11:25 ` Stephen C. Tweedie
1999-06-21 16:46 ` Kanoj Sarcar
1999-06-21 16:57 ` Stephen C. Tweedie
1999-06-21 17:36 ` Kanoj Sarcar
1999-06-21 17:49 ` Stephen C. Tweedie
1999-06-21 18:46 ` Kanoj Sarcar
1999-06-21 23:44 ` Kanoj Sarcar [this message]
1999-06-24 22:23 ` Andrea Arcangeli
1999-06-24 23:55 ` Kanoj Sarcar
1999-06-25 0:26 ` Andrea Arcangeli
1999-06-28 1:48 ` filecache/swapcache questions [RFC] [RFT] [PATCH] kanoj-mm12-2.3.8 Fix swapoff races Kanoj Sarcar
1999-06-28 10:35 ` Andrea Arcangeli
1999-06-28 17:11 ` filecache/swapcache questions [RFC] [RFT] [PATCH] kanoj-mm12-2.3.8 Kanoj Sarcar
1999-06-28 16:32 ` filecache/swapcache questions [RFC] [RFT] [PATCH] kanoj-mm12-2.3.8 Fix swapoff races Stephen C. Tweedie
1999-06-28 17:25 ` Kanoj Sarcar
1999-06-28 20:40 ` Stephen C. Tweedie
1999-06-28 21:11 ` Kanoj Sarcar
1999-06-28 22:12 ` Stephen C. Tweedie
1999-06-28 23:43 ` Kanoj Sarcar
1999-06-29 11:44 ` Stephen C. Tweedie
1999-06-29 22:01 ` Kanoj Sarcar
1999-06-30 17:28 ` Stephen C. Tweedie
1999-06-30 18:05 ` Kanoj Sarcar
1999-06-28 19:39 ` Chuck Lever
1999-06-28 19:55 ` filecache/swapcache questions [RFC] [RFT] [PATCH] kanoj-mm12-2.3.8 Kanoj Sarcar
1999-06-28 20:33 ` Chuck Lever
1999-06-28 20:51 ` Kanoj Sarcar
1999-06-28 21:32 ` Chuck Lever
1999-06-28 21:38 ` Kanoj Sarcar
1999-06-28 21:50 ` Chuck Lever
1999-06-28 22:15 ` Kanoj Sarcar
1999-06-29 11:23 ` Stephen C. Tweedie
1999-06-29 17:36 ` Kanoj Sarcar
1999-06-28 22:22 ` Stephen C. Tweedie
1999-06-28 22:21 ` Stephen C. Tweedie
1999-06-28 22:57 ` Andrea Arcangeli
1999-06-29 2:13 ` Chuck Lever
1999-06-29 12:01 ` Stephen C. Tweedie
1999-06-29 12:32 ` Andrea Arcangeli
1999-06-30 15:59 ` Stephen C. Tweedie
1999-06-29 1:00 ` Chuck Lever
1999-06-28 22:08 ` Stephen C. Tweedie
1999-06-28 22:59 ` Andrea Arcangeli
1999-06-29 0:53 ` Chuck Lever
1999-06-29 11:14 ` Stephen C. Tweedie
1999-06-28 22:09 ` Stephen C. Tweedie
1999-06-28 20:45 ` filecache/swapcache questions [RFC] [RFT] [PATCH] kanoj-mm12-2.3.8 Fix swapoff races Stephen C. Tweedie
1999-06-28 21:14 ` Chuck Lever
1999-06-28 21:25 ` filecache/swapcache questions [RFC] [RFT] [PATCH] kanoj-mm12-2.3.8 Kanoj Sarcar
1999-06-28 22:15 ` filecache/swapcache questions [RFC] [RFT] [PATCH] kanoj-mm12-2.3.8 Fix swapoff races Stephen C. Tweedie
1999-06-28 22:48 ` Andrea Arcangeli
1999-06-29 1:29 ` Chuck Lever
1999-06-29 11:58 ` Stephen C. Tweedie
1999-06-29 12:09 ` Andrea Arcangeli
1999-06-29 15:27 ` Chuck Lever
1999-06-29 11:55 ` Stephen C. Tweedie
1999-06-29 20:08 ` Andrea Arcangeli
1999-06-28 22:36 ` filecache/swapcache questions Stephen C. Tweedie
1999-06-28 23:24 ` Kanoj Sarcar
-- strict thread matches above, loose matches on Subject: below --
1999-06-15 7:16 Kanoj Sarcar
1999-06-15 7:32 ` Rik van Riel
1999-06-15 15:51 ` Kanoj Sarcar
1999-06-15 20:24 ` Rik van Riel
1999-06-15 21:02 ` Kanoj Sarcar
1999-06-16 20:37 ` Andrea Arcangeli
1999-06-17 23:33 ` Stephen C. Tweedie
1999-06-18 0:20 ` Kanoj Sarcar
1999-06-18 17:00 ` Stephen C. Tweedie
1999-06-18 17:03 ` Kanoj Sarcar
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