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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EB4B6C433F5 for ; Wed, 19 Jan 2022 14:36:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1355265AbiASOgf (ORCPT ); Wed, 19 Jan 2022 09:36:35 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46498 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1355150AbiASOfw (ORCPT ); Wed, 19 Jan 2022 09:35:52 -0500 Received: from mail-lf1-x129.google.com (mail-lf1-x129.google.com [IPv6:2a00:1450:4864:20::129]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 32FCAC06173E for ; Wed, 19 Jan 2022 06:35:52 -0800 (PST) Received: by mail-lf1-x129.google.com with SMTP id s30so10181249lfo.7 for ; Wed, 19 Jan 2022 06:35:52 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=j/VfafbxJ+vp6TLOD2d5aFbCUTwMb6Qu1uU6PUy6ZDY=; b=n4drYZuOGRVaLSjc8TCdkAEho4IJaYZ60oRRsBXU3CqKfIbodkO13DsVi9mKd75nEL h52jVxTTNYbXogL7r90cYBS0+S1KXGaHn4Akz7c3zMGhgX41CFjlZaz7pqiEvukt6Enn jKH0UKNqgSIxqEIvo6BYKPCJ2ro3lW6ACAwta68WfbVY9tbQDQ08s2yQ/kRuCqFLItPS N3sIu75MJeH83hoA30XnRH1YTbW44XuRWc3k5t9ogPfsmbkbCbFJctpZ/l1Gd84xZHx8 k70WEJcOILSZ27+O7OC2el6tOUg6PqstDykMHzl26HULJigKqwq2FCLOPczdOAGwInQq dfug== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=j/VfafbxJ+vp6TLOD2d5aFbCUTwMb6Qu1uU6PUy6ZDY=; b=PcXjFPv5YS7wV5gWUxjUMOaBv6QegrfflSahWRxaqbRqnfZJE4hwicpCWAOpV/qQWo 0UOUYz59gnGxCrxdskO1agWiajjdOop8UoqeNpxBfB12DL1ZbsjIlbrnmnV7u7oeHcy7 v0cILZ2qIUlul+Deri6Byp0mT6JIShHLL1HStyclIPD8zAhRT7j2hq65a8gY/3F37wkh BHdFANdHSxXjIu1sCHDUA4OcFrOVHywFFwpmmpqju29i+ES77gULXvZBFeRtha432ofs 049zAT1c2XwJ2U7GuDQBHArrkwurDoQQ8CFUQHbvjm+di+gdwUsLwTFTB2PDfHn3q4Tx qlxQ== X-Gm-Message-State: AOAM532XExom/T6rYrs3e0Wu7s5fOCCNUyKCYYWbAMPJQMMNZU7M7tNo YaKTxLLd5ITcgbCjPg6cfvE= X-Google-Smtp-Source: ABdhPJzM4vt8SBI2cvh6mvOuLZiZ9NRRzOvQ0dRdNvjMgpr1qMTGrZphWnTn9S8hUfj9Rxn72EwbnQ== X-Received: by 2002:a05:651c:30b:: with SMTP id a11mr19706790ljp.458.1642602950546; Wed, 19 Jan 2022 06:35:50 -0800 (PST) Received: from pc638.lan ([155.137.26.201]) by smtp.gmail.com with ESMTPSA id z13sm179943lfr.183.2022.01.19.06.35.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 19 Jan 2022 06:35:50 -0800 (PST) From: "Uladzislau Rezki (Sony)" To: Andrew Morton Cc: linux-mm@kvack.org, LKML , Christoph Hellwig , Matthew Wilcox , Nicholas Piggin , Uladzislau Rezki , Oleksiy Avramchenko , Uladzislau Rezki Subject: [PATCH 2/3] mm/vmalloc: Add adjust_search_size parameter Date: Wed, 19 Jan 2022 15:35:39 +0100 Message-Id: <20220119143540.601149-2-urezki@gmail.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220119143540.601149-1-urezki@gmail.com> References: <20220119143540.601149-1-urezki@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Uladzislau Rezki Extend the find_vmap_lowest_match() function with one more parameter. It is "adjust_search_size" boolean variable, so it is possible to control an accuracy of search block if a specific alignment is required. With this patch, a search size is always adjusted, to serve a request as fast as possible because of performance reason. But there is one exception though, it is short ranges where requested size corresponds to passed vstart/vend restriction together with a specific alignment request. In such scenario an adjustment wold not lead to success allocation. Signed-off-by: Uladzislau Rezki Signed-off-by: Uladzislau Rezki (Sony) --- mm/vmalloc.c | 37 ++++++++++++++++++++++++++++--------- 1 file changed, 28 insertions(+), 9 deletions(-) diff --git a/mm/vmalloc.c b/mm/vmalloc.c index ed0f9eaa61a9..52ee67107046 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -1192,22 +1192,28 @@ is_within_this_va(struct vmap_area *va, unsigned long size, /* * Find the first free block(lowest start address) in the tree, * that will accomplish the request corresponding to passing - * parameters. + * parameters. Please note, with an alignment bigger than PAGE_SIZE, + * a search length is adjusted to account for worst case alignment + * overhead. */ static __always_inline struct vmap_area * -find_vmap_lowest_match(unsigned long size, - unsigned long align, unsigned long vstart) +find_vmap_lowest_match(unsigned long size, unsigned long align, + unsigned long vstart, bool adjust_search_size) { struct vmap_area *va; struct rb_node *node; + unsigned long length; /* Start from the root. */ node = free_vmap_area_root.rb_node; + /* Adjust the search size for alignment overhead. */ + length = adjust_search_size ? size + align - 1 : size; + while (node) { va = rb_entry(node, struct vmap_area, rb_node); - if (get_subtree_max_size(node->rb_left) >= size && + if (get_subtree_max_size(node->rb_left) >= length && vstart < va->va_start) { node = node->rb_left; } else { @@ -1217,9 +1223,9 @@ find_vmap_lowest_match(unsigned long size, /* * Does not make sense to go deeper towards the right * sub-tree if it does not have a free block that is - * equal or bigger to the requested search size. + * equal or bigger to the requested search length. */ - if (get_subtree_max_size(node->rb_right) >= size) { + if (get_subtree_max_size(node->rb_right) >= length) { node = node->rb_right; continue; } @@ -1235,7 +1241,7 @@ find_vmap_lowest_match(unsigned long size, if (is_within_this_va(va, size, align, vstart)) return va; - if (get_subtree_max_size(node->rb_right) >= size && + if (get_subtree_max_size(node->rb_right) >= length && vstart <= va->va_start) { /* * Shift the vstart forward. Please note, we update it with @@ -1283,7 +1289,7 @@ find_vmap_lowest_match_check(unsigned long size, unsigned long align) get_random_bytes(&rnd, sizeof(rnd)); vstart = VMALLOC_START + rnd; - va_1 = find_vmap_lowest_match(size, align, vstart); + va_1 = find_vmap_lowest_match(size, align, vstart, false); va_2 = find_vmap_lowest_linear_match(size, align, vstart); if (va_1 != va_2) @@ -1434,12 +1440,25 @@ static __always_inline unsigned long __alloc_vmap_area(unsigned long size, unsigned long align, unsigned long vstart, unsigned long vend) { + bool adjust_search_size = true; unsigned long nva_start_addr; struct vmap_area *va; enum fit_type type; int ret; - va = find_vmap_lowest_match(size, align, vstart); + /* + * Do not adjust when: + * a) align <= PAGE_SIZE, because it does not make any sense. + * All blocks(their start addresses) are at least PAGE_SIZE + * aligned anyway; + * b) a short range where a requested size corresponds to exactly + * specified [vstart:vend] interval and an alignment > PAGE_SIZE. + * With adjusted search length an allocation would not succeed. + */ + if (align <= PAGE_SIZE || (align > PAGE_SIZE && (vend - vstart) == size)) + adjust_search_size = false; + + va = find_vmap_lowest_match(size, align, vstart, adjust_search_size); if (unlikely(!va)) return vend; -- 2.30.2