From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CE4BD44C4EA; Thu, 3 Sep 2026 09:29:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788427760; cv=none; b=USH4aDbcvODQx+iwM5RK42eMa57pQmGYT+8jLYc1ajmQ4Lxnbn5gZiCwXjCfwulsYZUm3ViOPGFNgxsH6dtv2RreuizevXJyVw5a6+TjM1f3eC5KEfJBdquGT5dQhp/pG+CFIL8YXx5Lo9mclWdgAI1GOKWyULaIE7F1xIcQOHs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788427760; c=relaxed/simple; bh=nn6iME8vaNp2UgCAoNFVxRTydFn/sut+ZKMPmrBTGcY=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=JFqEdqNuqbbWYIt0trpJgSH7RWt3SUVk74dD+hRpZ8XeV6oOZOxdWesijVUzX8cxdMxMbpa163C9WkgbowKbaHr6q6viGZatumWSTKe6VbQDyk7wvbqooxzOdPYnQdC/ZC63NjfrP5wFerrx+1Nh7eCenvt8lzM76AZ+E6hJKRc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Dc6BWw33; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Dc6BWw33" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 68CC71F00A3A; Thu, 3 Sep 2026 09:29:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788427758; bh=Vh6C9475l7fwGbJW046+hBcY6H+bSMsG/gNT4fxLjjs=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=Dc6BWw33eFqwAnKvbc/2ePznb+TuDl0/311Ux4UcmLpxp+Q7abEWleHxCmOOjQISw oxCvkgwUnvtbnN1PkSRcDoVvsxlVhC+tVD0ujqYa0LKTnJBa1Lxkpx/clqx1AifPrg 89KPF1umm9Vn3HD8boxt8mlCJEBKSPLFszutpFOFbMTY0woer4WLnp/ulHkGjUvo65 byO2lSGgdZd2gn6wbRjX2cmc6YakGRyG6RGGlMcDzz4zQ3AjxSuDeNrUrFMYvkfXow Ssj5NCfXrndepmRJnJTTmdkwbXvvAPcREhb15+xSkqIijaAybqP3yKMoF8SGTPEpxF QgQ0M0o4xuRvg== From: "Mike Rapoport (Microsoft)" Date: Thu, 03 Sep 2026 12:28:30 +0300 Subject: [PATCH v3 4/6] mm/vmalloc: make set_area_direct_map HUGE_VMAP friendly Precedence: bulk X-Mailing-List: linux-s390@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260903-execmem-set-vm-perms-v0-2-v3-4-949b64a9f755@kernel.org> References: <20260903-execmem-set-vm-perms-v0-2-v3-0-949b64a9f755@kernel.org> In-Reply-To: <20260903-execmem-set-vm-perms-v0-2-v3-0-949b64a9f755@kernel.org> To: Andrew Morton Cc: =?utf-8?q?Adrian_Barna=C5=9B?= , Albert Ou , Alexander Gordeev , Alexandre Ghiti , Andy Lutomirski , Borislav Petkov , Brendan Jackman , Catalin Marinas , Christian Borntraeger , Dave Hansen , David Hildenbrand , Gerald Schaefer , Heiko Carstens , Huacai Chen , Ingo Molnar , Len Brown , Mike Rapoport , 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 X-Mailer: b4 0.17-dev 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); - /* HUGE_VMALLOC passes small pages to set_direct_map */ - for (i = 0; i < area->nr_pages; i++) - if (page_address(area->pages[i])) - set_direct_map(area->pages[i], 1); + WARN_ON_ONCE(err); + } + } } /* -- 2.53.0