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Date: Fri, 3 Nov 2000 09:56:15 -0500
Message-Id: <200011031456.JAA21492@tsx-prime.MIT.EDU>
From: "Theodore Y. Ts'o" <tytso@MIT.EDU>
To: "David S. Miller" <davem@redhat.com>
CC: davej@suse.de, torvalds@transmeta.com, linux-kernel@vger.kernel.org,
        linux-mm@kvack.org
In-Reply-To: David S. Miller's message of Fri, 3 Nov 2000 03:33:37 -0800,
	<200011031133.DAA10265@pizda.ninka.net>
Subject: Re: BUG FIX?: mm->rss is modified in some places without holding the  page_table_lock
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   Date: Fri, 3 Nov 2000 03:33:37 -0800
   From: "David S. Miller" <davem@redhat.com>

      Given that we don't have a 64-bit atomic_t type, what do people
      think of Davej's patch?  (attached, below)

   Broken, in 9 out of 10 places where he adds page_table_lock
   acquisitions, this lock is already held --> instant deadlock.

   This report is complicated by the fact that people were forgetting
   that vmlist_*_{lock,unlock}(mm) was actually just spin_{lock,unlock}
   on mm->page_table_lock.  I fixed that already by removing the dumb
   vmlist locking macros which were causing all of this confusion.

Are you saying that the original bug report may not actually be a
problem?  Is ms->rss actually protected in _all_ of the right places, but
people got confused because of the syntactic sugar?

						- Ted
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