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 20C62C433EF for ; Sun, 12 Jun 2022 11:00:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236260AbiFLK7s (ORCPT ); Sun, 12 Jun 2022 06:59:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46986 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236372AbiFLK7o (ORCPT ); Sun, 12 Jun 2022 06:59:44 -0400 Received: from mail-pg1-x532.google.com (mail-pg1-x532.google.com [IPv6:2607:f8b0:4864:20::532]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 95F9A101D7 for ; Sun, 12 Jun 2022 03:59:43 -0700 (PDT) Received: by mail-pg1-x532.google.com with SMTP id y187so3179931pgd.3 for ; Sun, 12 Jun 2022 03:59:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=KOvsSU9XTYiyPG05mkPxbcZK+WV8KoV3IqO1Kxkz2mQ=; b=S3ZlbUrRojojjIhHasyuA8Q7ueqx9964FuHucVt6WQ6gQGh+UKvKpDAvYnkaX4tBJ4 1VjKNBYdx7iHsmu3IhV5u12mh4PITeDsIVzEfahlIBF2iGe+R3gEwChGEgcWR0VUZHfO EVZ8Rlb28+LTvFjHpQMlIloDJtOTwTGR525WK5gC+X1oQuNtWGGGCuScwDYo6k2p/BaY TiphGyY3Dq5kbEAfv8dYUlA81+/+JXrLoQiSJT1JixtX6VenU6fNpBkbjI1X314rvoeL INR+O5ozfQfVpUkO1dnUZlhiEd8VyfLHInwXzWCr7AybYvtKkq/EBd8wXp11C+JrJqK0 PDgA== 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:mime-version :content-transfer-encoding; bh=KOvsSU9XTYiyPG05mkPxbcZK+WV8KoV3IqO1Kxkz2mQ=; b=BBLQk3c6nNVfvLxeFjN4dq2QdIjYeIBGTJVyutaUSNPlp//eirewTu3Gor1ZrxaZbE +RADwpHt45+ibYuWTeYXiU8q5egfflE8jhU+IovvwnQW6FDy0Hy2gQdyMCwQpMcdA5z9 Nr+Skz9yo5VT6nujvbqkFaYak7YVfHfiOOev7FctUBsMOaQj6ZGgEJMPNk3VvhNCPgHr GUoiJKZ9GOtqbkqlaoHBIWpwavQuFG4OliBUvCEBKLXwOrHKH2ViEE79NMAQgXYJBAE4 7iSpVl8KedBtwyzp7QLQtPib/RaimTzriJMPTbCQA6uRkZFjj8yeqslaERHhmmpexEJW WJ0g== X-Gm-Message-State: AOAM533+CO1KvR5OuinzbRlSJ0k0lmvPhm84k5Wvn/7GNVxI01GV+sN0 6UhRPC7qcu6RqeMVFJYzibU= X-Google-Smtp-Source: ABdhPJy3zhw6Y6fH1x62wnxGwYD6JRNynUl32ho21VM2s+6nnYE4swFb317ciK7XozkVIWdJnKUF/A== X-Received: by 2002:a63:2a47:0:b0:3fe:2437:5d25 with SMTP id q68-20020a632a47000000b003fe24375d25mr22530054pgq.539.1655031582805; Sun, 12 Jun 2022 03:59:42 -0700 (PDT) Received: from localhost.localdomain ([139.177.225.240]) by smtp.gmail.com with ESMTPSA id x2-20020a1709028ec200b001621ce92196sm2853401plo.86.2022.06.12.03.59.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 12 Jun 2022 03:59:42 -0700 (PDT) From: wuchi To: akpm@linux-foundation.org, alexs@kernel.org, sjhuang@iluvatar.ai, sfr@canb.auug.org.au Cc: linux-kernel@vger.kernel.org Subject: [PATCH] lib/genalloc: Set chunk size to real size which gen_pool managed. Date: Sun, 12 Jun 2022 18:59:37 +0800 Message-Id: <20220612105937.30862-1-wuchi.zero@gmail.com> X-Mailer: git-send-email 2.32.0 (Apple Git-132) MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The demand size (chunk->avail > size > round_down(chunk->avail)) will lead to meaningless algo calls in gen_pool_alloc_algo_owner without the patch, alse move the follow code: size = nbits << order out of read-side critical section. Signed-off-by: wuchi --- lib/genalloc.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/lib/genalloc.c b/lib/genalloc.c index 00fc50d0a640..1b1843613fb8 100644 --- a/lib/genalloc.c +++ b/lib/genalloc.c @@ -193,6 +193,7 @@ int gen_pool_add_owner(struct gen_pool *pool, unsigned long virt, phys_addr_t ph if (unlikely(chunk == NULL)) return -ENOMEM; + size = nbits << pool->min_alloc_order; chunk->phys_addr = phys; chunk->start_addr = virt; chunk->end_addr = virt + size - 1; @@ -293,6 +294,7 @@ unsigned long gen_pool_alloc_algo_owner(struct gen_pool *pool, size_t size, return 0; nbits = (size + (1UL << order) - 1) >> order; + size = nbits << order; rcu_read_lock(); list_for_each_entry_rcu(chunk, &pool->chunks, next_chunk) { if (size > atomic_long_read(&chunk->avail)) @@ -314,7 +316,6 @@ unsigned long gen_pool_alloc_algo_owner(struct gen_pool *pool, size_t size, } addr = chunk->start_addr + ((unsigned long)start_bit << order); - size = nbits << order; atomic_long_sub(size, &chunk->avail); if (owner) *owner = chunk->owner; @@ -499,6 +500,7 @@ void gen_pool_free_owner(struct gen_pool *pool, unsigned long addr, size_t size, *owner = NULL; nbits = (size + (1UL << order) - 1) >> order; + size = nbits << order; rcu_read_lock(); list_for_each_entry_rcu(chunk, &pool->chunks, next_chunk) { if (addr >= chunk->start_addr && addr <= chunk->end_addr) { @@ -506,7 +508,6 @@ void gen_pool_free_owner(struct gen_pool *pool, unsigned long addr, size_t size, start_bit = (addr - chunk->start_addr) >> order; remain = bitmap_clear_ll(chunk->bits, start_bit, nbits); BUG_ON(remain); - size = nbits << order; atomic_long_add(size, &chunk->avail); if (owner) *owner = chunk->owner; -- 2.20.1