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From:   Muchun Song <smuchun@gmail.com>
Date:   Wed, 30 Dec 2020 21:41:30 +0800
Message-ID: <CAPSr9jHa8nT=Y1R2w9v7UUFJNXhCFohwDGwyv7WOWjKADZEchw@mail.gmail.com>
Subject: Re: [PATCH] mm/page_alloc: remove the static for local variable node_order
To:     Matthew Wilcox <willy@infradead.org>
Cc:     Hui Su <sh_def@163.com>, Andrew Morton <akpm@linux-foundation.org>,
        linux-mm@kvack.org, linux-kernel <linux-kernel@vger.kernel.org>,
        Michal Hocko <mhocko@suse.com>
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On Wed, Dec 30, 2020 at 8:45 PM Matthew Wilcox <willy@infradead.org> wrote:
>
> On Wed, Dec 30, 2020 at 07:40:14PM +0800, Hui Su wrote:
> > local variable node_order do not need the static here.
>
> It bloody well does.  It can be up to 2^10 entries on x86 (and larger
> on others) That's 4kB which you've now moved onto the stack.

This is not the first time I have seen similar changes. So what
do you think about adding a comment here to avoid another one
do this in the feature?

>
> Please, learn more about what you're doing.  I suggest sending patches
> to drivers/staging; that will help you learn how to submit patches to
> linux.