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 lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (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 73122C982C1 for ; Thu, 17 Sep 2026 05:41:47 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [127.0.0.1]) by lists.ozlabs.org (Postfix) with ESMTP id 4hll4R6DhYz2y21; Thu, 17 Sep 2026 15:41:43 +1000 (AEST) Authentication-Results: lists.ozlabs.org; arc=none smtp.remote-ip="2607:f8b0:4864:39::10" ARC-Seal: i=1; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1789623034; cv=none; b=jZPHP4kWWbVZwefTAzRzXyGkGIBG7X/YkmGll5pUCgJUuBCY0qmO4O6XVhv2Zo/JbaN01ABiNMm3uqDxYfcwupF77AxMS1hPK/IidKoGHjgRxPKkGGl6CC3Jk/u8IuDBkpwJqMegAUTXNVNxygKyMb0fcAUB1a0eJz8juvMbeFTsHYHiRErdtVTL1cQHjv0OBfTDRgIw9hTb5AUd8E3GcVtg1Vq3Oec32ACrc5JjS6I+9sF+tIQkpSWVPLFt6TyVA/cchwBpXg/xSMlJx841HLZWFjfx2RRuMCTeW+rCmNijdCVtnvTsS2AmBORCQTkQ8blA3hxIpACHZD1Eul8P8w== ARC-Message-Signature: i=1; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1789623034; c=relaxed/relaxed; bh=XToDi6fIsVYoV27kQlhNobBUYsIv/tm0eptMLl1rq74=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=LoF6YDll+fKB1mKhc+vLvIW7/MjH6PRYiai0dFGfhw1zbN6Wcb7r5+YcckxBlMqXRlWmpjrVy125I6gfACaoFZLTWdJtr44otYOHrcWkQRIfIUo1ziYXyqkN09/dvzqPMFmHL06xTlpSZnfZmQji9o/PcheRYg4vn5eSb2xeKLZRK3vTr2QDeU3rvp25AlMmKCFbs7eiqa10rbS5Ff6Fe2P26Jn5DNq/gCS9GC31+1A6X5uvpm1wRsF4AmpRFRdaTOpU9KxdsdsHV8MwKErbdmKl9PCWsWq+Rx2nJ4f4eEC2dx9wMHd9XaXV0EmAvx9N+UEgAnPhnSeY1cquT0FhvQ== ARC-Authentication-Results: i=1; lists.ozlabs.org; dmarc=pass (p=none dis=none) header.from=gmail.com; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20251104 header.b=ppNa+9H7; dkim-atps=neutral; spf=pass (client-ip=2607:f8b0:4864:39::10; helo=mail-pj2-x10.google.com; envelope-from=jiangwenxiaomi@gmail.com; receiver=lists.ozlabs.org) smtp.mailfrom=gmail.com Authentication-Results: lists.ozlabs.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20251104 header.b=ppNa+9H7; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=gmail.com (client-ip=2607:f8b0:4864:39::10; helo=mail-pj2-x10.google.com; envelope-from=jiangwenxiaomi@gmail.com; receiver=lists.ozlabs.org) Received: from mail-pj2-x10.google.com (mail-pj2-x10.google.com [IPv6:2607:f8b0:4864:39::10]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange x25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4hlkqY6qjHz2xfP for ; Thu, 17 Sep 2026 15:30:33 +1000 (AEST) Received: by mail-pj2-x10.google.com with SMTP id d9443c01a7336-2db22383fe8so2719275ad.2 for ; Wed, 16 Sep 2026 22:30:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1789623032; x=1790227832; darn=lists.ozlabs.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to:content-type; bh=XToDi6fIsVYoV27kQlhNobBUYsIv/tm0eptMLl1rq74=; b=ppNa+9H7MzTPjnEa16AAJ2mqARjIMZNb2ahfgM+723ui+JVKjvK/t3hgWIBsRrPyAo +YxDjVITA2BHN1hszeenuMCfjCmyp680v5DBblOOngG6l3CB6C4bZXqziQ4FGIrCTQcD lqnnN47YapSCbDESqOVfmO3cNznye6jH70ftFE2MHt6vCOSPneKgnxTa3ilMRY4wtfbf MysxBx8Fryktme5UJuuj+q4AtyZ6g13hfrzdLMD27m9kTGZtulG3lno+V7Kx1RJ/oU1x azOBCTRWb8xTUopLDB/XktAf5H5Kmpo5geICgc8cFEwSTrED3X3d9/bC8F9AUPXZx7fm bubQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1789623032; x=1790227832; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to:content-type; bh=XToDi6fIsVYoV27kQlhNobBUYsIv/tm0eptMLl1rq74=; b=ChnQK7fN/sHkMrrjjPRPSHO/939LZpE0jmhOfAXf9t9nZLrK5hDIfts4Sheh+FShMK WuWwRvQfvbOuhXkTO4BMD2udt96W9DiPwKXWoGaflsOSExzt8AkVAcatEQZxn8TGOPge +UCFCnecVxzfE6+2K19vdsXpsrC/9nP+tec/g+xDFhfXtPwvTpH/tH3w5rv64U0wIoUW Ji2q1p0XcgrhKq1vjWgMrA70LcnyXVo54qFgOgnFTh3SXp4kEl1kg1DSSgujKa9fyAa6 0Cz6KVAnH8ElY8FuHBBKQUFHItnoUULSmVMM4FTPKoEhTF8AwI0ann6xkU/ptD4tRFlW kZug== X-Forwarded-Encrypted: i=1; AKwUvBypnZZ2Ye2bSngq8lqsQDYCvyF4CPYbm3ZjKEtbyM08aY8GjXPq16/RCv/XnitzhLkV0BXVnPcfqb41e1c=@lists.ozlabs.org X-Gm-Message-State: AFuF++mjc6cBJZx+uRsQEkkRJqar4OcckH7Dg68pBgluR3jj7l0SOEw1 ou4wRlaVLV9AoCvYr9Ik72vyIXiUpqJht4N6KnI3hYfIS+1nLMiAzflP X-Gm-Gg: AYBFou3qfo8Rne/DerKLoarhzuBZ5HsGES37hagpt2B0+qiZghiYlHYZSoYtDZkwPnz j1JiLFWS62F+9ZVzLoicLTeVf5PFFqCtSlxhEvXrL6Ddy8x2SEEtS8eDazzzsrvpp9sMTrKsREB uQ+YVP2hWr9IHYce6SMtil15Taj29QHyFxuyAhWBUM1FRaAR8M6O3dWs6aTGI3BDAVHGHy8dvIo o4tbp57IA+2q3hQjtnlKsM1UCDj6pF8HszeZGJ9/BRDsOMBCi1TSpLkIVAiYP6qCL0fpj4Gv5z+ Kse+1eWtzqy50WdLYveR3ONAdVX9vdxx7n4n8zG9hsuUZb6M1szwRqDfPoQe6ZXes0MZzwVE4zA Al1OtQIbzY5sHi/ZZAA9ediobGDFzRH5icJZu4En7IXqOJLfVs9mcRyQkWfK832LVzlbGKSrPSz 0SWwLXreQcpEtq3BCsRuG2Xo8kD7i6MxBr29X7vhKB8UomPG7oH33jf5fW3hiZR9Tl1Pnw/GZwv 9j0t81zaMUg/iqeVE4tofhDfpE= X-Received: by 2002:a17:90b:4a51:b0:39d:ee20:1e28 with SMTP id 98e67ed59e1d1-39e1e510f73mr15610978a91.21.1789623031887; Wed, 16 Sep 2026 22:30:31 -0700 (PDT) Received: from mi-OptiPlex-7060.mioffice.cn ([43.224.245.234]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-39e3abada87sm1955836a91.14.2026.09.16.22.30.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 16 Sep 2026 22:30:31 -0700 (PDT) From: Wen Jiang To: akpm@linux-foundation.org, catalin.marinas@arm.com, linux-mm@kvack.org, urezki@gmail.com, will@kernel.org Cc: Xueyuan.chen21@gmail.com, ajd@linux.ibm.com, anshuman.khandual@arm.com, baohua@kernel.org, chleroy@kernel.org, david@kernel.org, dev.jain@arm.com, jiangwen6@xiaomi.com, leo.yan@arm.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, maddy@linux.ibm.com, mpe@ellerman.id.au, npiggin@gmail.com, rppt@kernel.org, ryan.roberts@arm.com, Xueyuan Chen Subject: [PATCH v8 07/10] mm/vmalloc: extend page table walk to support larger page_shift sizes and eliminate page table rewalk Date: Thu, 17 Sep 2026 13:29:30 +0800 Message-Id: <20260917052933.188679-8-jiangwenxiaomi@gmail.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20260917052933.188679-1-jiangwenxiaomi@gmail.com> References: <20260917052933.188679-1-jiangwenxiaomi@gmail.com> X-Mailing-List: linuxppc-dev@lists.ozlabs.org List-Id: List-Help: List-Owner: List-Post: List-Archive: , List-Subscribe: , , List-Unsubscribe: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: "Barry Song (Xiaomi)" vmap_pages_range_noflush_walk() (formerly vmap_small_pages_range_noflush()) provides a clean interface by taking struct page **pages and mapping them via direct PTE iteration. This avoids the page table rewalk seen when using vmap_range_noflush() for page_shift values other than PAGE_SHIFT. Extend it to support larger page_shift values, and add PMD- and contiguous-PTE mappings as well. Rename it to vmap_pages_range_noflush_walk() since it now handles more than just small pages. For vmalloc() allocations with VM_ALLOW_HUGE_VMAP, we no longer need to iterate over pages one by one via vmap_range_noflush(), which would otherwise lead to page table rewalk. The code is now unified with the PAGE_SHIFT case by simply calling vmap_pages_range_noflush_walk(). Signed-off-by: Barry Song (Xiaomi) Signed-off-by: Wen Jiang Tested-by: Xueyuan Chen Tested-by: Leo Yan Reviewed-by: Dev Jain --- mm/vmalloc.c | 84 +++++++++++++++++++++++++++++++--------------------- 1 file changed, 50 insertions(+), 34 deletions(-) diff --git a/mm/vmalloc.c b/mm/vmalloc.c index a0508bdb7d36f..cf1daf931a6f6 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -535,8 +535,10 @@ void vunmap_range(unsigned long addr, unsigned long end) static int vmap_pages_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, pgprot_t prot, struct page **pages, int *nr, - pgtbl_mod_mask *mask) + pgtbl_mod_mask *mask, unsigned int shift) { + unsigned long pfn, size; + unsigned int steps; int err = 0; pte_t *pte; @@ -567,9 +569,10 @@ static int vmap_pages_pte_range(pmd_t *pmd, unsigned long addr, break; } - set_pte_at(&init_mm, addr, pte, mk_pte(page, prot)); - (*nr)++; - } while (pte++, addr += PAGE_SIZE, addr != end); + pfn = page_to_pfn(page); + size = vmap_set_ptes(pte, addr, end, pfn, prot, shift); + steps = PFN_DOWN(size); + } while (pte += steps, *nr += steps, addr += size, addr != end); lazy_mmu_mode_disable(); *mask |= PGTBL_PTE_MODIFIED; @@ -579,60 +582,88 @@ static int vmap_pages_pte_range(pmd_t *pmd, unsigned long addr, static int vmap_pages_pmd_range(pud_t *pud, unsigned long addr, unsigned long end, pgprot_t prot, struct page **pages, int *nr, - pgtbl_mod_mask *mask) + pgtbl_mod_mask *mask, unsigned int shift) { pmd_t *pmd; unsigned long next; + int err; pmd = pmd_alloc_track(&init_mm, pud, addr, mask); if (!pmd) return -ENOMEM; do { next = pmd_addr_end(addr, end); - if (vmap_pages_pte_range(pmd, addr, next, prot, pages, nr, mask)) - return -ENOMEM; + + if (shift >= PMD_SHIFT) { + struct page *page = pages[*nr]; + phys_addr_t phys_addr; + + if (WARN_ON(!page)) + return -ENOMEM; + if (WARN_ON(!pfn_valid(page_to_pfn(page)))) + return -EINVAL; + + phys_addr = page_to_phys(page); + + if (vmap_try_huge_pmd(pmd, addr, next, phys_addr, prot, shift)) { + *mask |= PGTBL_PMD_MODIFIED; + *nr += 1 << (PMD_SHIFT - PAGE_SHIFT); + continue; + } + } + err = vmap_pages_pte_range(pmd, addr, next, prot, pages, nr, mask, shift); + if (err) + return err; } while (pmd++, addr = next, addr != end); return 0; } static int vmap_pages_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end, pgprot_t prot, struct page **pages, int *nr, - pgtbl_mod_mask *mask) + pgtbl_mod_mask *mask, unsigned int shift) { pud_t *pud; unsigned long next; + int err; pud = pud_alloc_track(&init_mm, p4d, addr, mask); if (!pud) return -ENOMEM; do { next = pud_addr_end(addr, end); - if (vmap_pages_pmd_range(pud, addr, next, prot, pages, nr, mask)) - return -ENOMEM; + err = vmap_pages_pmd_range(pud, addr, next, prot, pages, nr, mask, shift); + if (err) + return err; } while (pud++, addr = next, addr != end); return 0; } static int vmap_pages_p4d_range(pgd_t *pgd, unsigned long addr, unsigned long end, pgprot_t prot, struct page **pages, int *nr, - pgtbl_mod_mask *mask) + pgtbl_mod_mask *mask, unsigned int shift) { p4d_t *p4d; unsigned long next; + int err; p4d = p4d_alloc_track(&init_mm, pgd, addr, mask); if (!p4d) return -ENOMEM; do { next = p4d_addr_end(addr, end); - if (vmap_pages_pud_range(p4d, addr, next, prot, pages, nr, mask)) - return -ENOMEM; + err = vmap_pages_pud_range(p4d, addr, next, prot, pages, nr, mask, shift); + if (err) + return err; } while (p4d++, addr = next, addr != end); return 0; } -static int vmap_small_pages_range_noflush(unsigned long addr, unsigned long end, - pgprot_t prot, struct page **pages) +/* + * It can take an array of pages which are not all contiguous, but it + * may have contiguous chunks, as hinted by @shift. + */ +static int vmap_pages_range_noflush_walk(unsigned long addr, unsigned long end, + pgprot_t prot, struct page **pages, unsigned int shift) { unsigned long start = addr; pgd_t *pgd; @@ -647,7 +678,7 @@ static int vmap_small_pages_range_noflush(unsigned long addr, unsigned long end, next = pgd_addr_end(addr, end); if (pgd_bad(*pgd)) mask |= PGTBL_PGD_MODIFIED; - err = vmap_pages_p4d_range(pgd, addr, next, prot, pages, &nr, &mask); + err = vmap_pages_p4d_range(pgd, addr, next, prot, pages, &nr, &mask, shift); if (err) break; } while (pgd++, addr = next, addr != end); @@ -670,27 +701,12 @@ static int vmap_small_pages_range_noflush(unsigned long addr, unsigned long end, int __vmap_pages_range_noflush(unsigned long addr, unsigned long end, pgprot_t prot, struct page **pages, unsigned int page_shift) { - unsigned int i, nr = (end - addr) >> PAGE_SHIFT; - WARN_ON(page_shift < PAGE_SHIFT); - if (!IS_ENABLED(CONFIG_HAVE_ARCH_HUGE_VMALLOC) || - page_shift == PAGE_SHIFT) - return vmap_small_pages_range_noflush(addr, end, prot, pages); + if (!IS_ENABLED(CONFIG_HAVE_ARCH_HUGE_VMALLOC)) + page_shift = PAGE_SHIFT; - for (i = 0; i < nr; i += 1U << (page_shift - PAGE_SHIFT)) { - int err; - - err = vmap_range_noflush(addr, addr + (1UL << page_shift), - page_to_phys(pages[i]), prot, - page_shift); - if (err) - return err; - - addr += 1UL << page_shift; - } - - return 0; + return vmap_pages_range_noflush_walk(addr, end, prot, pages, page_shift); } int vmap_pages_range_noflush(unsigned long addr, unsigned long end, -- 2.34.1