From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 7089331194C for ; Tue, 1 Sep 2026 06:24:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788243869; cv=none; b=XJ5itAE0JfilE4Ol0LZK1z+b6lvv1n+Nu6JouKnjFxv1HH6sLmm0BpOpxTLo12LicxuYnVMzUlzeTECWwUK3LHwarR52f5up8hkaW/rWRnLu09Us2MDD8M739AG82O+NwIZcLODaHieaMywC0/4HntySK+ZE2o5P8Gu3/U+DUb8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788243869; c=relaxed/simple; bh=yGLpijKUnjl1pokicm77fJ/NhLlkoUbwE3wNND1awVA=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=krSww/gyC2mG3u5SuU+peNqhQEFZXx4Ipn22oWpRpXfRQux/921PS43+6u3a6DrjxbIbsCLN5QORJrhkjGk/z8dNVQSxXqfD2jY49RHCTjmQaKwdcvMEuVHZAkzftN08a0sw5jUzlPdT8tivQPnsJt4I3+lf+HRAM5qtxM/uOZM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b=bH/tFopJ; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b="bH/tFopJ" Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id EA2811756; Mon, 31 Aug 2026 23:24:22 -0700 (PDT) Received: from [10.164.19.53] (unknown [10.164.19.53]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 40DCF3F85F; Mon, 31 Aug 2026 23:24:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1788243866; bh=yGLpijKUnjl1pokicm77fJ/NhLlkoUbwE3wNND1awVA=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=bH/tFopJqfTyFZdaC2O5krSp6aX3s4cOqW1YfXSVEx7FdoXaPlQDAuMXyICg02PKP o0Nm7zjaLI95sCxwUqMzNrvLVC961DwPDaKG5yy/XqXZFrLCCihKnmxI1PdpBd9XYJ c1SJppfR2ExblfSqCMlH/X3uQuTDi5m4qZGeA/NA= Message-ID: <55e7bc2a-dfdd-4cbb-9bf6-ea3bf4b03cce@arm.com> Date: Tue, 1 Sep 2026 11:54:17 +0530 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 3/8] mm: move anon-exclusive batch helper to mm.h To: Barry Song Cc: akpm@linux-foundation.org, david@kernel.org, ljs@kernel.org, hughd@google.com, chrisl@kernel.org, kasong@tencent.com, riel@surriel.com, liam@infradead.org, vbabka@kernel.org, harry@kernel.org, jannh@google.com, lance.yang@linux.dev, baolin.wang@linux.alibaba.com, shikemeng@huaweicloud.com, nphamcs@gmail.com, baoquan.he@linux.dev, youngjun.park@lge.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, rppt@kernel.org, surenb@google.com, mhocko@suse.com, pfalcato@suse.de, ryan.roberts@arm.com, anshuman.khandual@arm.com References: <20260901054358.4049095-1-dev.jain@arm.com> <20260901054358.4049095-4-dev.jain@arm.com> Content-Language: en-US From: Dev Jain In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On 01/09/26 11:19 am, Barry Song wrote: > On Tue, Sep 1, 2026 at 1:44 PM Dev Jain wrote: >> >> In preparation for optimizing large folio unmapping, we need to reuse >> the page_anon_exclusive_batch helper in rmap.c and rmap.h and obey the >> existing use in mprotect.c . >> >> Therefore, move it from mprotect.c to mm.h. Gate with CONFIG_MMU since >> both rmap and mprotect users are built only for CONFIG_MMU. >> >> While at it, change start_idx and max_len to unsigned long type for >> future proofing against THP support at >= PUD level. Also shorten >> expected_anon_exclusive -> anon_exclusive. >> >> Signed-off-by: Dev Jain >> --- >> include/linux/mm.h | 19 +++++++++++++++++++ >> mm/mprotect.c | 17 ----------------- >> 2 files changed, 19 insertions(+), 17 deletions(-) >> >> diff --git a/include/linux/mm.h b/include/linux/mm.h >> index dd09c438fa23e..63da8813bc5df 100644 >> --- a/include/linux/mm.h >> +++ b/include/linux/mm.h >> @@ -244,6 +244,25 @@ static inline unsigned long folio_page_idx(const struct folio *folio, >> return page - &folio->page; >> } >> >> +#ifdef CONFIG_MMU >> +/* >> + * Get max length of consecutive PTEs pointing to PageAnonExclusive() pages or >> + * !PageAnonExclusive() pages, starting from start_idx. Caller must enforce >> + * that the PTEs point to consecutive pages of the same anon large folio. >> + */ >> +static __always_inline int page_anon_exclusive_batch(unsigned long start_idx, >> + unsigned long max_len, struct page *first_page, bool anon_exclusive) >> +{ >> + int idx; >> + >> + for (idx = start_idx + 1; idx < start_idx + max_len; ++idx) { >> + if (anon_exclusive != PageAnonExclusive(first_page + idx)) >> + break; >> + } >> + return idx - start_idx; >> +} >> +#endif >> + > > Hi Dev, > > I really don't want everything to become a top-level header > file. If these are only mm-internal things, could we move them > to mm/internal.h or another more appropriate header? What do you suggest? I had it in mm/internal.h initially, but because I had to use the helper this time in patch 4, I couldn't do that. The helper will now be used by mprotect.c, rmap.c and rmap.h. I can keep it in rmap.h and make mprotect.c include rmap.h too. > > Best Regards > Barry