From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Date: Sun, 28 Apr 2019 08:13:53 +0000 Subject: Re: DISCONTIGMEM is deprecated Message-Id: <20190428081353.GB30901@infradead.org> List-Id: References: <20190419094335.GJ18914@techsingularity.net> <20190419140521.GI7751@bombadil.infradead.org> <0100016a461809ed-be5bd8fc-9925-424d-9624-4a325a7a8860-000000@email.amazonses.com> <25cabb7c-9602-2e09-2fe0-cad3e54595fa@linux.ee> In-Reply-To: <25cabb7c-9602-2e09-2fe0-cad3e54595fa@linux.ee> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Meelis Roos Cc: Christopher Lameter , Mel Gorman , Andrew Morton , Mikulas Patocka , James Bottomley , linux-parisc@vger.kernel.org, linux-mm@kvack.org, Vlastimil Babka , LKML , linux-arch@vger.kernel.org, Tony Luck , Fenghua Yu , linux-ia64@vger.kernel.org On Tue, Apr 23, 2019 at 07:49:57PM +0300, Meelis Roos wrote: > > > ia64 (looks complicated ...) > > > > Well as far as I can tell it was not even used 12 or so years ago on > > Itanium when I worked on that stuff. > > My notes tell that on UP ia64 (RX2620), !NUMA was broken with both > SPARSEMEM and DISCONTIGMEM. NUMA+SPARSEMEM or !NUMA worked. Even > NUMA+DISCONTIGMEM worked, that was my config on 2-CPU RX2660. ia64 has a such a huge number of memory model choices. Maybe we need to cut it down to a small set that actually work. That includes fund bits like the 'VIRTUAL_MEM_MAP' option where the comment claims: # VIRTUAL_MEM_MAP and FLAT_NODE_MEM_MAP are functionally equivalent. # VIRTUAL_MEM_MAP has been retained for historical reasons. but it still is selected as the default if sparsemem is not enabled..