From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Teigland Date: Wed, 12 Nov 2008 17:14:10 -0600 Subject: [Cluster-devel] Re: [DLM] Fix up memory alloc/kmap In-Reply-To: <1226401377.9571.2.camel@quoit> References: <1224860742.25004.130.camel@quoit> <1226401377.9571.2.camel@quoit> Message-ID: <20081112231410.GF29551@redhat.com> List-Id: To: cluster-devel.redhat.com MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit On Tue, Nov 11, 2008 at 11:02:57AM +0000, Steven Whitehouse wrote: > In addition kmap was being used incorrectly. The reason that this hasn't > been seen before is that the pages are allocated using ls->ls_allocation > which doesn't allow highmem pages to be returned. I haven't changed that > since although kmap implies a GFP_KERNEL allocation, without highmem > pages, they will be no-ops for now and thus safe. Also sendpage does its > own kmap (if required, which is only if the protocol is emulating > sendpage via sock_no_sendpage) so that the k(un)map pair around that > call can be removed. Sorry, I don't understand this, it's late and I'm probably being dense... - We can remove kmap/kunmap from send_to_sock() because... - We can remove kmap/kunmap from sctp_init_assoc() because... - We cannot remove kmap/kunmap from dlm_lowcomms_get_buffer/ dlm_lowcomms_commit_buffer because...