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 02438C433F5 for ; Sat, 28 May 2022 01:51:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235475AbiE1BvP (ORCPT ); Fri, 27 May 2022 21:51:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43776 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231386AbiE1BvP (ORCPT ); Fri, 27 May 2022 21:51:15 -0400 Received: from out30-57.freemail.mail.aliyun.com (out30-57.freemail.mail.aliyun.com [115.124.30.57]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8C2A339830 for ; Fri, 27 May 2022 18:51:12 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R391e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04395;MF=xiaoguang.wang@linux.alibaba.com;NM=1;PH=DS;RN=3;SR=0;TI=SMTPD_---0VEZnDx9_1653702669; Received: from localhost(mailfrom:xiaoguang.wang@linux.alibaba.com fp:SMTPD_---0VEZnDx9_1653702669) by smtp.aliyun-inc.com(127.0.0.1); Sat, 28 May 2022 09:51:10 +0800 From: Xiaoguang Wang To: io-uring@vger.kernel.org Cc: axboe@kernel.dk, asml.silence@gmail.com Subject: [PATCH v3] io_uring: defer alloc_hint update to io_file_bitmap_set() Date: Sat, 28 May 2022 09:51:09 +0800 Message-Id: <20220528015109.48039-1-xiaoguang.wang@linux.alibaba.com> X-Mailer: git-send-email 2.14.4.44.g2045bb6 In-Reply-To: <587a9737-9979-302e-4484-dfdbebe29d78@kernel.dk> References: <587a9737-9979-302e-4484-dfdbebe29d78@kernel.dk> Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org io_file_bitmap_get() returns a free bitmap slot, but if it isn't used later, such as io_queue_rsrc_removal() returns error, in this case, we should not update alloc_hint at all, which still should be considered as a valid candidate for next io_file_bitmap_get() calls. To fix this issue, only update alloc_hint in io_file_bitmap_set(). Signed-off-by: Xiaoguang Wang --- v3: Revert io_file_bitmap_set() type changes. V2: Delete unnecessary check against to alloc_hint. --- fs/io_uring.c | 11 +++-------- 1 file changed, 3 insertions(+), 8 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index ff50e5f1753d..8f476e8760bf 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -5419,15 +5419,11 @@ static int io_file_bitmap_get(struct io_ring_ctx *ctx) unsigned long nr = ctx->nr_user_files; int ret; - if (table->alloc_hint >= nr) - table->alloc_hint = 0; - do { ret = find_next_zero_bit(table->bitmap, nr, table->alloc_hint); - if (ret != nr) { - table->alloc_hint = ret + 1; + if (ret != nr) return ret; - } + if (!table->alloc_hint) break; @@ -9654,8 +9650,7 @@ static inline void io_file_bitmap_set(struct io_file_table *table, int bit) { WARN_ON_ONCE(test_bit(bit, table->bitmap)); __set_bit(bit, table->bitmap); - if (bit == table->alloc_hint) - table->alloc_hint++; + table->alloc_hint = bit + 1; } static inline void io_file_bitmap_clear(struct io_file_table *table, int bit) -- 2.14.4.44.g2045bb6