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 0E6C73CA497; Sun, 23 Aug 2026 11:47:04 +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=1787485625; cv=none; b=vGDFYv1/V1jedPaXYh2dpRMp+WTEhxkwMUgcd85b2HwKods9olnmSw9mmDR5m5hdc/d5Gn3Y0cUzkRZOTXkkHyOi3UQTyTNoAsF9Jg6UWu/iT9gKyK+9dXjLpoOEiEj1bGD9Ej1EgppySQqDb2Epqp6gzdtZLa0tA/x1netCFqQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787485625; c=relaxed/simple; bh=ObSy1Srnr2wwaKpK5XKSyY61dD30oFw71iPOumKLGOk=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=rqJ+myx0m+zBU6jNXM+6BWjRX2/T7UHwIYKwzCji3XLb+oGWPRCUIzRMDcCu4XAoBh4sD2oKNy5qKEA0jFZK89/dfrwRgixOPm6uKJy8Iovev0hMqp/qKTUm8r7lGtiXV7xnW0c8E8nauH2xrtagSJElDIwoT7hq4KqVf+5nZYM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=MIM7FsVq; 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="MIM7FsVq" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 879281F000E9; Sun, 23 Aug 2026 11:46:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1787485623; bh=JNbaKBJKZiPBWFXiQZSzBAcWECdyW1psqwwnhscXogA=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=MIM7FsVqFQDwxEVqELOzWyRouVAcV/zT99s47WF8sDGz0/F3hE64vb8Nc7ZGQ6TZQ guKkDJgym0SQoUX7GbxQVEzrbPfAdBfUlyqfFTws30j9T4oZBaJ7m1FzhBRlM8Y541 hk6+RYrgiHCw7kuAJrpr8CJzF6KPkdCCz8i4QVZemN8l3ab46v110aaqS4AR28vYwb XER8Eo2D0JhPLqBYOMP72mYryOFYB59Iciip8vmWeHAvcBSgfnOEyWj3W057KVdhr+ 06QPG/smqTW3N4dHyZfBcpY04dITAwYDaqovV12DxZIUwhAjWFVLe3/5Bz9DqWxsND NhbUa8zPT1Xug== From: "Mike Rapoport (Microsoft)" Date: Sun, 23 Aug 2026 14:46:15 +0300 Subject: [PATCH v2 4/6] mm/vmalloc: make set_area_direct_map HUGE_VMAP friendly Precedence: bulk X-Mailing-List: linux-pm@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: <20260823-execmem-set-vm-perms-v0-2-v2-4-b013a37d84b3@kernel.org> References: <20260823-execmem-set-vm-perms-v0-2-v2-0-b013a37d84b3@kernel.org> In-Reply-To: <20260823-execmem-set-vm-perms-v0-2-v2-0-b013a37d84b3@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 a3e2e4244c0f..395358b363fc 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -3361,12 +3361,15 @@ 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