From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id B9FD4C79F82 for ; Tue, 8 Sep 2026 11:12:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=qE5NwVzsN2BzrOO5o8wvglaekFUALkKc4kBKRql+Ovk=; b=Fr1Z8ZUaVHOnHw p+dgMvKtQQFzTzKyylhxzWo4ZAxZnLU7vgmm3WKbmBcBtt5KmRKrS6c5v0u9B0NmKsULMZkbmQqQj fX0deOCamnQnYSz/xZ98RwXGpot7fXV2n16MCNlgD5xJigX9NTVd1s7dEUc3ZvPKY6CUcp8JRoEym nhMBuS40eH0CwXi8CZGzVp7nZ2WPhnbgfVyybfvDuGnElLdS+LUZjgvo42ZVP3j+dyx9c9w87YASE QbQbSuaN6muUSr5BphxI79I+6FWPIlB3MLpeZqkRyXf1uQv+ukmRshCGbG1OPYJMfNml3GrE9paUr q/N0/bYEE9pAPZ8IShJg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1x3tkb-00000008rIZ-1gph; Tue, 08 Sep 2026 11:12:29 +0000 Received: from sea.source.kernel.org ([2600:3c0a:e001:78e:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1x3tka-00000008rIL-0HGs; Tue, 08 Sep 2026 11:12:28 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 7FC6D412D4; Tue, 8 Sep 2026 11:12:27 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5CCEF1F00A3A; Tue, 8 Sep 2026 11:12:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788865947; bh=+8zEZzYXKDWjMscmRriONU7KthgG+ikNsFsSCx8Kl7U=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=j0YvJw5XRabkDRwY07U/Nr51yNYPwxCyv+z3STNN3DvhiZbQ2LLliKVdQxWj7ppq+ zv9BhrPbhWQJAVescoenFKCBK8dIe4FnLE41q0oGajg4NKGEFMqenvTN8qGcT5KALG fQMcuKC+7NJE6h1JkAWJGjRFe7kuNrWWBJi63S3F7fZ6YaNOkz2UdfAh8vmFC5EXcp bHxMCUACQA7hH4tJIGFFrWqfN8HNtsfKVFr7W/ZxLarzhz8HriGsNqqucFmQRW8PiZ axL0F5cVKdHUSq7uODecJDsNjdMRPzRgNMNU9BLViewX8ONteqjFxwoO/2vXDW+IOk Uivt3hlM1NCZw== Date: Tue, 8 Sep 2026 14:12:12 +0300 From: Mike Rapoport To: "David Hildenbrand (Arm)" Cc: Andrew Morton , Adrian =?utf-8?Q?Barna=C5=9B?= , Albert Ou , Alexander Gordeev , Alexandre Ghiti , Andy Lutomirski , Borislav Petkov , Brendan Jackman , Catalin Marinas , Christian Borntraeger , Dave Hansen , Gerald Schaefer , Heiko Carstens , Huacai Chen , Ingo Molnar , Len Brown , Palmer Dabbelt , Paul Walmsley , Pavel Machek , Peter Zijlstra , "H. Peter Anvin" , "Rafael J. Wysocki" , Ryan Roberts , Sven Schnelle , Thomas Gleixner , Uladzislau Rezki , Vasily Gorbik , WANG Xuerui , Will Deacon , x86@kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-pm@vger.kernel.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, loongarch@lists.linux.dev Subject: Re: [PATCH v3 4/6] mm/vmalloc: make set_area_direct_map HUGE_VMAP friendly Message-ID: References: <20260903-execmem-set-vm-perms-v0-2-v3-0-949b64a9f755@kernel.org> <20260903-execmem-set-vm-perms-v0-2-v3-4-949b64a9f755@kernel.org> <2b0f5877-e71a-4824-adeb-5af2dd8b0269@kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <2b0f5877-e71a-4824-adeb-5af2dd8b0269@kernel.org> X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org On Tue, Sep 08, 2026 at 12:41:48PM +0200, David Hildenbrand (Arm) wrote: > On 9/3/26 11:28, Mike Rapoport (Microsoft) wrote: > > set_area_direct_map() always updates direct map alias permissions in > > single page increments. > > > > For HUGE_VMAP areas it's suboptimal. Not only the loop in > > set_area_direct_map() needlessly has more iterations (e.g times 512 on > > x86), but it also causes fragmentation of the direct map that could be > > avoided for the HUGE_VMAP areas populated with large pages. > > > > All pages in an area are always of the same order: either same-order > > large pages when VM_ALLOW_HUGE_VMAP is set and all huge pages were > > successfully allocated, or order-0 page when VM_ALLOW_HUGE_VMAP is > > cleared or when huge pages allocation fails and fallback path is taken. > > > > Instead of updating the direct map permissions for every order-0 page in > > an area, use the area's page_order as the loop increment and update the > > large pages in one call to set_direct_map_{invalid,default}_noflush(). > > > > Signed-off-by: Mike Rapoport (Microsoft) > > --- > > mm/vmalloc.c | 13 ++++++++----- > > 1 file changed, 8 insertions(+), 5 deletions(-) > > > > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > > index 5506b180f5c27..6ed6c160abed7 100644 > > --- a/mm/vmalloc.c > > +++ b/mm/vmalloc.c > > @@ -3367,12 +3367,15 @@ static inline void set_area_direct_map(const struct vm_struct *area, > > int (*set_direct_map)(struct page *page, > > unsigned int nr)) > > { > > - unsigned long i; > > + unsigned int nr = (1U << vm_area_page_order(area)); > > + > > + for (unsigned long i = 0; i < area->nr_pages; i += nr) { > > + if (page_address(area->pages[i])) { > > + int err = set_direct_map(area->pages[i], nr); > > Do we really expect some pages to have a directmap and others not? Every page in the area can be allocated separately and __vmalloc_area_node() has if (!(gfp_mask & (GFP_DMA | GFP_DMA32))) gfp_mask |= __GFP_HIGHMEM; so generally speaking yes :) > -- > Cheers, > > David -- Sincerely yours, Mike. _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv