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Fri, 25 Apr 2025 08:32:33 -0700 (PDT) Date: Fri, 25 Apr 2025 11:32:32 -0400 From: Johannes Weiner To: Wenchao Hao Cc: Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm/compaction: do not break pages whose order is larger than target order Message-ID: <20250425153232.GA108388@cmpxchg.org> References: <20250424153815.4003-1-haowenchao22@gmail.com> <20250424194200.GD840@cmpxchg.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Fri, Apr 25, 2025 at 10:28:42PM +0800, Wenchao Hao wrote: > On Fri, Apr 25, 2025 at 3:42 AM Johannes Weiner wrote: > > > > On Thu, Apr 24, 2025 at 11:38:15PM +0800, Wenchao Hao wrote: > > > When scanning free pages for memory compaction, if the compaction target > > > order is explicitly specified, do not split pages in buddy whose order > > > are larger than compaction target order. > > > > Have you observed this to be an issue in practice? > > > > compact_finished() would have bailed if such a page had existed. > > > > Yes, when proactive memory compaction is enabled, there may be situations > where the order of isolated free pages is greater than the compaction > requested order, and compact_finished() will return continue. proactive compaction has an order of -1?