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Date:   Fri, 18 Aug 2023 11:03:09 -0700
From:   Andrew Morton <akpm@linux-foundation.org>
To:     Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc:     linux-kernel@vger.kernel.org, linux-mm@kvack.org,
        songmuchun@bytedance.com, mike.kravetz@oracle.com,
        willy@infradead.org
Subject: Re: [PATCH v6] mm/filemap: remove hugetlb special casing in
 filemap.c
Message-Id: <20230818110309.e9debd8b988cb8ca4a1019be@linux-foundation.org>
In-Reply-To: <20230817181836.103744-1-sidhartha.kumar@oracle.com>
References: <20230817181836.103744-1-sidhartha.kumar@oracle.com>
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On Thu, 17 Aug 2023 11:18:36 -0700 Sidhartha Kumar <sidhartha.kumar@oracle.com> wrote:

> Perf was used to check the performance differences after the patch. Overall
> the performance is similar to mainline with a very small larger overhead that
> occurs in __filemap_add_folio() and hugetlb_add_to_page_cache(). This is because
> of the larger overhead that occurs in xa_load() and xa_store() as the
> xarray is now using more entries to store hugetlb folios in the page cache.

So... why merge the patch?  To save 40 lines of code?

I mean, if a patch which added 40 lines yielded a "very small"
reduction in overhead, we'd probably merge it!

Or is there some wider reason for this which the changelog omitted?