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Sun, 22 Feb 2026 15:51:03 -0800 (PST) Date: Sun, 22 Feb 2026 23:51:03 +0000 From: Wei Yang To: Andrew Morton Cc: Wei Yang , will@kernel.org, aneesh.kumar@kernel.org, npiggin@gmail.com, peterz@infradead.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, Qi Zheng , "David Hildenbrand (Arm)" Subject: Re: [PATCH] mm/mmu_gather: define RCU version tlb_remove_table_one() in CONFIG_MMU_GATHER_RCU_TABLE_FREE Message-ID: <20260222235103.firb34hgaddqsc2i@master> Reply-To: Wei Yang References: <20260222004512.839-1-richard.weiyang@gmail.com> <20260222114201.095379dd766b68dcecbab1c5@linux-foundation.org> Precedence: bulk X-Mailing-List: linux-arch@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260222114201.095379dd766b68dcecbab1c5@linux-foundation.org> User-Agent: NeoMutt/20170113 (1.7.2) On Sun, Feb 22, 2026 at 11:42:01AM -0800, Andrew Morton wrote: >On Sun, 22 Feb 2026 00:45:12 +0000 Wei Yang wrote: > >> Before commit 718b13861d22 ("x86: mm: free page table pages by RCU >> instead of semi RCU"), the page table pages will be freed by semi RCU, >> that is: >> >> - batch table freeing: asynchronous free by RCU >> - single table freeing: IPI + synchronous free >> >> This commit introduce a RCU version for single table freeing to support >> PT_RECLAIM. While it is not necessary to limit the RCU version only in >> CONFIG_PT_RECLAIM. It is reasonable to asynchronous free single table by >> RCU if CONFIG_MMU_GATHER_RCU_TABLE_FREE. >> >> This patch moves the definition of single table freeing in >> CONFIG_MMU_GATHER_RCU_TABLE_FREE, so we have both RCU version >> batch/single table freeing if CONFIG_MMU_GATHER_RCU_TABLE_FREE. > >What are the expected (and measured!) benefits of this? > No, this is just a cleanup. Last time checked with Qi and thought it worth a formal patch. [1] [1]: http://lkml.kernel.org/r/fd90c84b-9829-4699-b7df-c43020519ec9@linux.dev -- Wei Yang Help you, Help me