[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <alpine.DEB.2.10.1508191701010.30666@chino.kir.corp.google.com>
Date: Wed, 19 Aug 2015 17:02:54 -0700 (PDT)
From: David Rientjes <rientjes@...gle.com>
To: Jiang Liu <jiang.liu@...ux.intel.com>
cc: Andrew Morton <akpm@...ux-foundation.org>,
Mel Gorman <mgorman@...e.de>,
Mike Galbraith <umgwanakikbuti@...il.com>,
Peter Zijlstra <peterz@...radead.org>,
"Rafael J . Wysocki" <rafael.j.wysocki@...el.com>,
Tang Chen <tangchen@...fujitsu.com>, Tejun Heo <tj@...nel.org>,
Cliff Whickman <cpw@....com>,
Robin Holt <robinmholt@...il.com>,
Tony Luck <tony.luck@...el.com>, linux-mm@...ck.org,
linux-hotplug@...r.kernel.org, linux-kernel@...r.kernel.org,
x86@...nel.org
Subject: Re: [Patch V3 3/9] sgi-xp: Replace cpu_to_node() with cpu_to_mem()
to support memoryless node
On Wed, 19 Aug 2015, Jiang Liu wrote:
> > Why not simply fix build_zonelists_node() so that the __GFP_THISNODE
> > zonelists are set up to reference the zones of cpu_to_mem() for memoryless
> > nodes?
> >
> > It seems much better than checking and maintaining every __GFP_THISNODE
> > user to determine if they are using a memoryless node or not. I don't
> > feel that this solution is maintainable in the longterm.
> Hi David,
> There are some usage cases, such as memory migration,
> expect the page allocator rejecting memory allocation requests
> if there is no memory on local node. So we have:
> 1) alloc_pages_node(cpu_to_node(), __GFP_THISNODE) to only allocate
> memory from local node.
> 2) alloc_pages_node(cpu_to_mem(), __GFP_THISNODE) to allocate memory
> from local node or from nearest node if local node is memoryless.
>
Right, so do you think it would be better to make the default zonelists be
setup so that cpu_to_node()->zonelists == cpu_to_mem()->zonelists and then
individual callers that want to fail for memoryless nodes check
populated_zone() themselves?
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists