From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 27 Sep 2000 15:56:08 +0200 From: Andrea Arcangeli Subject: Re: [patch] vmfixes-2.4.0-test9-B2 - fixing deadlocks Message-ID: <20000927155608.D27898@athlon.random> References: <20000925172442.J2615@redhat.com> <20000925190347.E27677@athlon.random> <20000925190657.N2615@redhat.com> <20000925213242.A30832@athlon.random> <20000925205457.Y2615@redhat.com> <20000926160554.B13832@athlon.random> <20000926191027.A16692@athlon.random> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: ; from cr@sap.com on Wed, Sep 27, 2000 at 10:11:43AM +0200 Sender: owner-linux-mm@kvack.org Return-Path: To: Christoph Rohland Cc: "Stephen C. Tweedie" , Ingo Molnar , Linus Torvalds , Rik van Riel , Roger Larsson , MM mailing list , linux-kernel@vger.kernel.org List-ID: On Wed, Sep 27, 2000 at 10:11:43AM +0200, Christoph Rohland wrote: > I just checked one oracle system and it did not lock the memory. And I If that memory is used for I/O cache then such memory should released when the system runs into swap instead of swapping it out too (otherwise it's not cache anymore and it could be slower than re-reading from disk the real data in rawio). > Customers with performance problems very often start with too little > memory, but they cannot upgrade until this really big job finishes :-( > > Another issue about shm swapping is interactive transactions, where > some users have very large contexts and go for a coffee before > submitting. This memory can be swapped. Agreed, that's why I said shm performance under swap is very important as well (I'm not understimating it). But again: if the shm contains I/O cache it should be released and not swapped out. Swapping out shmfs that contains I/O cache would be exactly like swapping out page-cache. Andrea -- 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.eu.org/Linux-MM/