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Subject: Re: [PATCH] mm/slub: embed __slab_alloc to its caller
From:   Abel Wu <abel.w@icloud.com>
In-Reply-To: <alpine.DEB.2.22.394.2102021009470.50959@www.lameter.com>
Date:   Wed, 3 Feb 2021 09:41:58 +0800
Cc:     Pekka Enberg <penberg@kernel.org>,
        David Rientjes <rientjes@google.com>,
        Joonsoo Kim <iamjoonsoo.kim@lge.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Vlastimil Babka <vbabka@suse.cz>, hewenliang4@huawei.com,
        wuyun.wu@huawei.com, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org
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References: <20210202080515.2689-1-abel.w@icloud.com>
 <alpine.DEB.2.22.394.2102021009470.50959@www.lameter.com>
To:     Christoph Lameter <cl@linux.com>
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> On Feb 2, 2021, at 6:11 PM, Christoph Lameter <cl@linux.com> wrote:
> 
> On Tue, 2 Feb 2021, Abel Wu wrote:
> 
>> Since slab_alloc_node() is the only caller of __slab_alloc(), embed
>> __slab_alloc() to its caller to save function call overhead. This
>> will also expand the caller's code block size a bit, but hackbench
>> tests on both host and guest didn't show a difference w/ or w/o
>> this patch.
> 
> slab_alloc_node is an always_inline function. It is intentional that only
> the fast path was inlined and not the slow path.

Oh I got it. Thanks for your excellent explanation.

Best Regards,
	Abel