Re: [PATCH v6] mm/filemap: remove hugetlb special casing in filemap.c

From: Andrew Morton
Date: Fri Aug 18 2023 - 14:04:09 EST


On Thu, 17 Aug 2023 11:18:36 -0700 Sidhartha Kumar <sidhartha.kumar@xxxxxxxxxx> 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?