From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 14 Aug 2007 14:15:12 -0700 (PDT) From: Christoph Lameter Subject: Re: [RFC 4/9] Atomic reclaim: Save irq flags in vmscan.c In-Reply-To: <20070814204454.GC22202@one.firstfloor.org> Message-ID: References: <20070814153021.446917377@sgi.com> <20070814153501.766137366@sgi.com> <20070814203329.GA22202@one.firstfloor.org> <20070814204454.GC22202@one.firstfloor.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Andi Kleen Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: On Tue, 14 Aug 2007, Andi Kleen wrote: > > Hmmmm... The spinlock is its own flag. > > Yes, but it's not CPU local. Taking the spinlock from another CPU's > interrupt handler is perfectly safe, just not from the local CPU. > If you use the spinlock as flag you would need to lock out everybody. So every spinlock would have an array of chars sized to NR_CPUS and set the flag when the lock is taken? -- 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: email@kvack.org