From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Bottomley Subject: Re: scsi command slab allocation under memory pressure Date: 31 Jan 2003 08:46:44 -0500 Sender: linux-scsi-owner@vger.kernel.org Message-ID: <1044020591.2002.16.camel@mulgrave> References: <20030129104731.A2811@beaverton.ibm.com> <3E382E2C.4030201@splentec.com> <20030129121117.A3389@beaverton.ibm.com> <20030130225738.1874c2e0.akpm@digeo.com> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: Received: (from root@localhost) by pogo.mtv1.steeleye.com (8.9.3/8.9.3) id FAA19445 for ; Fri, 31 Jan 2003 05:46:52 -0800 In-Reply-To: <20030130225738.1874c2e0.akpm@digeo.com> List-Id: linux-scsi@vger.kernel.org To: Andrew Morton Cc: Patrick Mansfield , luben@splentec.com, SCSI Mailing List On Fri, 2003-01-31 at 01:57, Andrew Morton wrote: > Please do not reinvent the mm/mempool.c functionality. > > 'twould be better to just use it ;) Unfortunately, in this instance, mempool is a slight overkill. The problem is that we need to guarantee that a command (or set of commands) be available to a given device regardless of what's going on in the rest of the system. Thus we might need a mempool for each active device, rather than a mempool for all devices and a mechanism for giving fine grained control to the pool depth per device. Mempool would fit all of the above, I was just concerned that it looks to be a rather heavy addition (in terms of structure size) per device. James