From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 74A321A239A for ; Wed, 8 Apr 2026 02:51:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775616715; cv=none; b=Xb1Mt5N2jMNUG+b6wY2xZt+w+889K+v/YpklKhgSBGfurU6fM3qJ8pCOFInxYD6Hty5+5BOoOlFlhqc2VGbIj0oDy4VA1OC4v+zyhS25mRCuC8z6wyP65ijpyWaLykvsKzPfcf/VC853dZyVbmILbdCwER7sqrh4EVPNxrIqKTI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775616715; c=relaxed/simple; bh=zaZ8iI84M3gZDm1hFnDFMcUBYZoPlyljQ9RYRlcP8K4=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=hBfgasQfFZwzcqi9rVe61atAvwyc13Zk4yvApFoot3qw1pGd5ERMU29hhvvsuKVRlHAVKgZyNkMuqbXVrQiakCpNXy+31neFtJOFI+1MWZsq1PJ5bK8iP82K/Xp7a8LyupHv2K9THkNwqgd/JdL5x8F5m/4iajBjIlweuR40X+M= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=aKK4jkTJ; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="aKK4jkTJ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5CE7EC19421; Wed, 8 Apr 2026 02:51:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1775616715; bh=zaZ8iI84M3gZDm1hFnDFMcUBYZoPlyljQ9RYRlcP8K4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=aKK4jkTJ5pywEdQAoHMXFLD7R7Mhv5Fnty4Vg5GxCHuMhVafbgKxAzllimIrmfxVz k1L/3VDHClK8mu07LOtpbPbjoWCRs94wrnmP0v3vjSgBSk4dKGJxmq6GZ+4RiXf5Dv ezwuHP0DNCVYdCLaWPBR6CI5rzkzA4fXL0f4ql25HHBqmX3Bfk+9nCWJzmRnuaoFET I1fRFIrfVxkyGP5oWkJc0xIXD2ijRTNoV7RyahVXzArx7n+PTOrf7sKnCQxgOUf0dW 1TEHNCYbfGT0eEbzT7ZkcdMF7XDAbWYwl/ASDIGj1w56XtQsqOVKIMnnNRCUmoXLHN A21hs6OW851Rw== From: "Barry Song (Xiaomi)" To: linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, catalin.marinas@arm.com, will@kernel.org, akpm@linux-foundation.org, urezki@gmail.com Cc: linux-kernel@vger.kernel.org, anshuman.khandual@arm.com, ryan.roberts@arm.com, ajd@linux.ibm.com, rppt@kernel.org, david@kernel.org, Xueyuan.chen21@gmail.com, "Barry Song (Xiaomi)" Subject: [RFC PATCH 7/8] mm/vmalloc: Coalesce same page_shift mappings in vmap to avoid pgtable zigzag Date: Wed, 8 Apr 2026 10:51:14 +0800 Message-Id: <20260408025115.27368-8-baohua@kernel.org> X-Mailer: git-send-email 2.39.3 (Apple Git-146) In-Reply-To: <20260408025115.27368-1-baohua@kernel.org> References: <20260408025115.27368-1-baohua@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit For vmap(), detect pages with the same page_shift and map them in batches, avoiding the pgtable zigzag caused by per-page mapping. Signed-off-by: Barry Song (Xiaomi) --- mm/vmalloc.c | 24 ++++++++++++++++++++---- 1 file changed, 20 insertions(+), 4 deletions(-) diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 6643ec0288cd..3c3b7217693a 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -3551,6 +3551,8 @@ static int vmap_contig_pages_range(unsigned long addr, unsigned long end, pgprot_t prot, struct page **pages) { unsigned int count = (end - addr) >> PAGE_SHIFT; + unsigned int prev_shift = 0, idx = 0; + unsigned long map_addr = addr; int err; err = kmsan_vmap_pages_range_noflush(addr, end, prot, pages, @@ -3562,15 +3564,29 @@ static int vmap_contig_pages_range(unsigned long addr, unsigned long end, unsigned int shift = PAGE_SHIFT + get_vmap_batch_order(pages, count - i, i); - err = vmap_range_noflush(addr, addr + (1UL << shift), - page_to_phys(pages[i]), prot, shift); - if (err) - goto out; + if (!i) + prev_shift = shift; + + if (shift != prev_shift) { + err = vmap_small_pages_range_noflush(map_addr, addr, + prot, pages + idx, + min(prev_shift, PMD_SHIFT)); + if (err) + goto out; + prev_shift = shift; + map_addr = addr; + idx = i; + } addr += 1UL << shift; i += 1U << (shift - PAGE_SHIFT); } + /* Remaining */ + if (map_addr < end) + err = vmap_small_pages_range_noflush(map_addr, end, + prot, pages + idx, min(prev_shift, PMD_SHIFT)); + out: flush_cache_vmap(addr, end); return err; -- 2.39.3 (Apple Git-146)