Re: [PATCH] mm/hugetlb: Get rid of NODEMASK_ALLOC

From: Mike Kravetz <mike.kravetz@oracle.com>
To: Oscar Salvador <osalvador@suse.de>, akpm@linux-foundation.org
Cc: n-horiguchi@ah.jp.nec.com, linux-mm@kvack.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] mm/hugetlb: Get rid of NODEMASK_ALLOC
Date: Tue, 2 Apr 2019 11:37:20 -0700	[thread overview]
Message-ID: <8152cb75-da42-0fe7-9aac-82b1b8929f09@oracle.com> (raw)
In-Reply-To: <20190402133415.21983-1-osalvador@suse.de>

On 4/2/19 6:34 AM, Oscar Salvador wrote:
> NODEMASK_ALLOC is used to allocate a nodemask bitmap, ant it does it by
                                                          ^
> first determining whether it should be allocated in the stack or dinamically
                                                                    ^
> depending on NODES_SHIFT.
> Right now, it goes the dynamic path whenever the nodemask_t is above 32
> bytes.
> 
> Although we could bump it to a reasonable value, the largest a nodemask_t
> can get is 128 bytes, so since __nr_hugepages_store_common is called from
> a rather shore stack we can just get rid of the NODEMASK_ALLOC call here.
               ^
In addition, the possible call stacks after this routine are not too deep.
Worst case is high order page allocation.

> 
> This reduces some code churn and complexity.
> 
> Signed-off-by: Oscar Salvador <osalvador@suse.de>

Not a huge deal, but a few typos in the commit message.  Thanks for the
clean up.
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>

-- 
Mike Kravetz