From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <20040209182013.59140.qmail@web14302.mail.yahoo.com> Date: Mon, 9 Feb 2004 10:20:13 -0800 (PST) From: Kanoj Sarcar Subject: Re: Documentation/vm/locking: why not hold two PT locks? In-Reply-To: <87r7x4ns3m.fsf@cs.uga.edu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: owner-linux-mm@kvack.org Return-Path: To: Ed L Cashin Cc: Robert Love , linux-mm@kvack.org List-ID: --- Ed L Cashin wrote: > Kanoj Sarcar writes: > > ... > > Its been a while since I wrote up those rules in > > the "locking" file, but the example that Robert > has > > pointed out involving two different threads, each > > crabbing one mm lock and trying for the next one, > > is the deadlock I had in mind. There may have been > > new changes in 2.5 timeframe that also requires > > the rule, I am not sure. > > Thanks, Kanoj! > > After further looking into it, one thing in > Documentation/vm/locking > does seem out of date. It says that "Page stealers > hold kernel_lock > to protect against a bunch of races." > > The only page stealing code that I can find is in > rmap.c and vmscan.c. > When vmscan.c:shrink_caches and its callees need to > unmap a page, > rmap.c:try_to_unmap gets called. But nowhere is > there a lock_kernel > call that I could find. Instead, they use trylocks > and get the page > table lock before stealing a page. > > Are there other page stealers? > Hi, When "locking" came into being, vmscan was the only page stealer. Thanks. Kanoj > -- > --Ed L Cashin PGP public key: > http://noserose.net/e/pgp/ > > -- > 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-mm.org/ . > Don't email: > aart@kvack.org __________________________________ Do you Yahoo!? Yahoo! Finance: Get your refund fast by filing online. http://taxes.yahoo.com/filing.html -- 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-mm.org/ . Don't email: aart@kvack.org