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 1B591C4321E for ; Mon, 5 Dec 2022 09:39:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231230AbiLEJjj (ORCPT ); Mon, 5 Dec 2022 04:39:39 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53954 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230092AbiLEJji (ORCPT ); Mon, 5 Dec 2022 04:39:38 -0500 Received: from dggsgout11.his.huawei.com (dggsgout11.his.huawei.com [45.249.212.51]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 64C1A18B14; Mon, 5 Dec 2022 01:39:37 -0800 (PST) Received: from mail02.huawei.com (unknown [172.30.67.153]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4NQdmg5WH9z4f3k6N; Mon, 5 Dec 2022 17:39:31 +0800 (CST) Received: from [10.174.176.73] (unknown [10.174.176.73]) by APP1 (Coremail) with SMTP id cCh0CgAH_qxVvI1jJs9iBg--.28715S3; Mon, 05 Dec 2022 17:39:34 +0800 (CST) Subject: Re: [PATCH v2 4/5] blk-iocost: fix sleeping in atomic context warnning To: Yu Kuai , Tejun Heo , Jens Axboe Cc: hch@lst.de, josef@toxicpanda.com, cgroups@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, yi.zhang@huawei.com, "yukuai (C)" References: <20221104023938.2346986-1-yukuai1@huaweicloud.com> <20221104023938.2346986-5-yukuai1@huaweicloud.com> <3da991c6-21e4-8ed8-ba75-ccb92059f0ae@huaweicloud.com> <1f52ccb1-c357-a2a0-ef9d-48d7e2eb51f8@kernel.dk> From: Yu Kuai Message-ID: Date: Mon, 5 Dec 2022 17:39:33 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=gbk; format=flowed Content-Transfer-Encoding: 8bit X-CM-TRANSID: cCh0CgAH_qxVvI1jJs9iBg--.28715S3 X-Coremail-Antispam: 1UD129KBjvdXoW7Gr1UJF17JFWUZr17AFy7ZFb_yoWDKrb_ur yvvr4UJ3s8uF4v9a90kryDAFZag3W7Jr1kGryfJF17Zw1Fvay7JF1xXr93JFZaqrW0vr4U Cryj93ya9w129jkaLaAFLSUrUUUUUb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUIcSsGvfJTRUUUb3kFF20E14v26r4j6ryUM7CY07I20VC2zVCF04k26cxKx2IYs7xG 6rWj6s0DM7CIcVAFz4kK6r1j6r18M28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8w A2z4x0Y4vE2Ix0cI8IcVAFwI0_tr0E3s1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Gr1j 6F4UJwA2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x0267AKxVW0oV Cq3wAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0 I7IYx2IY67AKxVWUXVWUAwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j6r 4UM4x0Y48IcVAKI48JM4x0x7Aq67IIx4CEVc8vx2IErcIFxwACI402YVCY1x02628vn2kI c2xKxwCYjI0SjxkI62AI1cAE67vIY487MxAIw28IcxkI7VAKI48JMxC20s026xCaFVCjc4 AY6r1j6r4UMI8I3I0E5I8CrVAFwI0_Jr0_Jr4lx2IqxVCjr7xvwVAFwI0_JrI_JrWlx4CE 17CEb7AF67AKxVWUtVW8ZwCIc40Y0x0EwIxGrwCI42IY6xIIjxv20xvE14v26r1j6r1xMI IF0xvE2Ix0cI8IcVCY1x0267AKxVW8JVWxJwCI42IY6xAIw20EY4v20xvaj40_Zr0_Wr1U MIIF0xvEx4A2jsIE14v26r1j6r4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Gr0_Gr1UYxBIda VFxhVjvjDU0xZFpf9x0JUp6wZUUUUU= X-CM-SenderInfo: 51xn3trlr6x35dzhxuhorxvhhfrp/ X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Hi, Tejun ÔÚ 2022/11/23 18:22, Yu Kuai дµÀ: > Hi, Tejun > > ÔÚ 2022/11/23 8:42, Tejun Heo дµÀ: >> On Tue, Nov 22, 2022 at 05:14:29PM -0700, Jens Axboe wrote: >>>>> Then match_strdup() and kfree() in match_NUMBER() can be replaced with >>>>> get_buffer() and put_buffer(). >>>> >>>> Sorry about the late reply. Yeah, something like this. > I wonder can we just use arary directly in stack? The max size is just 24 bytes, which should be fine: HEX: "0xFFFFFFFFFFFFFFFF" --> 18 DEC: "18446744073709551615" --> 20 OCT: "01777777777777777777777" --> 23 Something like: #define U64_MAX_SIZE 23 static int match_strdup_local(const substring_t *s, char *buf) { size_t len = s->to - s->from; if (len > U64_MAX_SIZE) return -ERANGE; if (!s->from) return -EINVAL; memcpy(buf, s->from, len); buf[len] = '\0'; return 0; } static int match_u64int(substring_t *s, u64 *result, int base) { char buf[U64_MAX_SIZE + 1]; int ret; u64 val; ret = match_strdup_local(s, buf); if (ret) return ret; ret = kstrtoull(buf, base, &val); if (!ret) *result = val;; return ret; }