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Shutemov" Subject: Re: [PATCH v2 0/3] trim the uses of compound_head() Message-ID: References: <20210224084807.2179942-1-yuzhao@google.com> <20210226091718.2927291-1-yuzhao@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Feb 26, 2021 at 11:52:03AM +0100, Vlastimil Babka wrote: > On 2/26/21 10:17 AM, Yu Zhao wrote: > > Patch series "mm: lru related cleanups" starting at commit 42895ea73bcd > > ("mm/vmscan.c: use add_page_to_lru_list()") bloated vmlinux by 1777 > > bytes, according to: > > https://lore.kernel.org/linux-mm/85b3e8f2-5982-3329-c20d-cf062b8da71e@suse.cz/ > > Huh, I thought Andrew didn't want to send it for 5.12: > https://lore.kernel.org/linux-mm/20210223145011.0181eed96ab0091a493b51f6@linux-foundation.org/ > > > It turned out many places inline Page{Active,Unevictable} which in > > turn include compound_head(). > > > > From the v1: > > Removing compound_head() entirely from Page{Active,Unevictable} may > > not be the best option (for the moment) because there may be other > > cases that need compound_head(). > > > > In addition to picking a couple pieces of low-hanging fruit, this v2 > > removes compound_head() completely from Page{Active,Unevictable}. > > > > bloat-o-meter result before and after the series: > > add/remove: 0/0 grow/shrink: 6/92 up/down: 697/-7656 (-6959) > > Good that you found a way to more than undo the bloat then. But we need to be > careful so bugs are not introduced due to pressure to not have bloated 5.12. I was very conservative and only picked a few pieces of low-hanging fruit. The pressure is good -- if you hadn't noticed it and Andrew hadn't been emphatic about it, it'd have been left for another time and to another person, and so on.