From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 27 Apr 2005 23:33:35 -0700 From: Andrew Morton Subject: Re: [PATCH/RFC 0/4] VM: Manual and Automatic page cache reclaim Message-Id: <20050427233335.492d0b6f.akpm@osdl.org> In-Reply-To: <20050427150848.GR8018@localhost> References: <20050427150848.GR8018@localhost> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Martin Hicks Cc: linux-mm@kvack.org, raybry@sgi.com, ak@suse.de List-ID: Martin Hicks wrote: > > The patches introduce two different ways to free up page cache from a > node: manually through a syscall and automatically through flag > modifiers to a mempolicy. Backing up and thinking about this a bit more.... > Currently if a job is started and there is page cache lying around on a > particular node then allocations will spill onto remote nodes and page > cache won't be reclaimed until the whole system is short on memory. > This can result in a signficiant performance hit for HPC applications > that planned on that memory being allocated locally. Why do it this way at all? Is it not possible to change the page allocator's zone fallback mechanism so that once the local node's zones' pages are all allocated, we don't simply advance onto the next node? Instead, could we not perform a bit of reclaim on this node's zones first? Only advance onto the next nodes if things aren't working out? -- 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