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Date:   Fri, 14 Dec 2018 10:24:52 -0800
From:   Matthew Wilcox <willy@infradead.org>
To:     Roman Gushchin <guroan@gmail.com>
Cc:     linux-mm@kvack.org, Alexey Dobriyan <adobriyan@gmail.com>,
        Johannes Weiner <hannes@cmpxchg.org>,
        Michal Hocko <mhocko@suse.com>,
        Vlastimil Babka <vbabka@suse.cz>, linux-kernel@vger.kernel.org,
        kernel-team@fb.com, Roman Gushchin <guro@fb.com>
Subject: Re: [RFC 1/4] mm: refactor __vunmap() to avoid duplicated call to
 find_vm_area()
Message-ID: <20181214182452.GD10600@bombadil.infradead.org>
References: <20181214180720.32040-1-guro@fb.com>
 <20181214180720.32040-2-guro@fb.com>
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On Fri, Dec 14, 2018 at 10:07:17AM -0800, Roman Gushchin wrote:
> __vunmap() calls find_vm_area() twice without an obvious reason:
> first directly to get the area pointer, second indirectly by calling
> remove_vm_area(), which is again searching for the area.
> 
> To remove this redundancy, let's split remove_vm_area() into
> __remove_vm_area(struct vmap_area *), which performs the actual area
> removal, and remove_vm_area(const void *addr) wrapper, which can
> be used everywhere, where it has been used before.
> 
> On my test setup, I've got up to 12% speed up on vfree()'ing 1000000
> of 4-pages vmalloc blocks.
> 
> Signed-off-by: Roman Gushchin <guro@fb.com>
> Acked-by: Johannes Weiner <hannes@cmpxchg.org>

Reviewed-by: Matthew Wilcox <willy@infradead.org>