Date: Fri, 11 Jul 2014 10:42:05 -0400
From: Tejun Heo <tj@kernel.org>
To: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>, Mel Gorman <mgorman@suse.de>,
        David Rientjes <rientjes@google.com>,
        Mike Galbraith <umgwanakikbuti@gmail.com>,
        Peter Zijlstra <peterz@infradead.org>,
        "Rafael J . Wysocki" <rafael.j.wysocki@intel.com>,
        Christoph Lameter <cl@linux-foundation.org>,
        Vladimir Davydov <vdavydov@parallels.com>,
        Johannes Weiner <hannes@cmpxchg.org>,
        "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
        Rik van Riel <riel@redhat.com>, Wanpeng Li <liwanp@linux.vnet.ibm.com>,
        Zhang Yanfei <zhangyanfei@cn.fujitsu.com>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Jianyu Zhan <nasa4836@gmail.com>, malc <av1474@comtv.ru>,
        Joonsoo Kim <iamjoonsoo.kim@lge.com>,
        Fabian Frederick <fabf@skynet.be>, Tony Luck <tony.luck@intel.com>,
        linux-mm@kvack.org, linux-hotplug@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [RFC Patch V1 07/30] mm: Use cpu_to_mem()/numa_mem_id() to
 support memoryless node
Message-ID: <20140711144205.GA27706@htj.dyndns.org>
References: <1405064267-11678-1-git-send-email-jiang.liu@linux.intel.com>
 <1405064267-11678-8-git-send-email-jiang.liu@linux.intel.com>
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Hello,

On Fri, Jul 11, 2014 at 03:37:24PM +0800, Jiang Liu wrote:
> When CONFIG_HAVE_MEMORYLESS_NODES is enabled, cpu_to_node()/numa_node_id()
> may return a node without memory, and later cause system failure/panic
> when calling kmalloc_node() and friends with returned node id.

The patch itself looks okay to me but is this the right way to handle
this?  Can't we just let the allocators fall back to the nearest node
with memory?  Why do we need to impose this awareness of memory-less
node on all the users?

Thanks.

-- 
tejun
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