From patchwork Thu Mar 9 16:58:30 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jens Axboe X-Patchwork-Id: 13168003 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 8B461C61DA4 for ; Thu, 9 Mar 2023 17:04:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230102AbjCIREl (ORCPT ); Thu, 9 Mar 2023 12:04:41 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57184 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230135AbjCIREP (ORCPT ); Thu, 9 Mar 2023 12:04:15 -0500 Received: from mail-pf1-x433.google.com (mail-pf1-x433.google.com [IPv6:2607:f8b0:4864:20::433]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1F3FDE7777 for ; Thu, 9 Mar 2023 08:58:32 -0800 (PST) Received: by mail-pf1-x433.google.com with SMTP id cp12so1926498pfb.5 for ; Thu, 09 Mar 2023 08:58:32 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20210112.gappssmtp.com; s=20210112; t=1678381111; h=content-transfer-encoding:content-language:cc:to:subject:from :user-agent:mime-version:date:message-id:from:to:cc:subject:date :message-id:reply-to; bh=6aCfv4STRRGIFkooAouQgbwMrAUQE9quqkucriFKPYk=; b=Llo1R/k5N0zREQ/pLb/1BYlV3O55lWVv/Gla1SBVOy2tG8jh3oPNCsiXcyFYSCRfIZ jNOM3E7OxXQMoYrDhi8pddlu9Pcp0ZyiVAaO/jXllP+JGXPObOjatWzQl72YXcKFTd+5 LFkUTge+oi82I5jGM2hO2eTJgyYefzeZNpoVMYhDT6JsrhS6/LDRwe8FSBJ7bsKD8o5o aF1G80q//U+OgryOciiWNdyNjSj2wWCnNiQaH8vz4z/hk1Y2kxeqIIJ0ooBzDu09df0a sBSGnnUbBFhH6ppnUP9EMXaFQ4TnWbpe40xtkl7IQZZ/33e2KkwtO4YGU2T+zTUEBqUf U1cg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1678381111; h=content-transfer-encoding:content-language:cc:to:subject:from :user-agent:mime-version:date:message-id:x-gm-message-state:from:to :cc:subject:date:message-id:reply-to; bh=6aCfv4STRRGIFkooAouQgbwMrAUQE9quqkucriFKPYk=; b=iGtpICe8iz28R+VF2noW9iSMHcBB/WRla7dN9ZffUlXx/lSIGqyfjn8eiZy0zdD1un AgltVZwEUS8Ql/M6ICh0O/6hgEeyDVzQwCNEwiMycmXQXITonf/VnvOD+xN6eZsLi/FZ raMD50gBTYYRt1IMMapDTgS+NOHPcxrHMvhuqVqu4FsJcQWzdk5JPXlHyTgcxw2Pao3a MG5uzSup1dPZu/orbcRiyraWU/mkWxhi7Oew0cP8XZSNJPSOm0d6l3ErktV/2oh+q+AZ 9omgvV6NxKMcvFxFAdV1V8/JR9qhHsNfMh9rJ3zIGOs5btP8VGdpbwhIG2h+A0S2PH5h Kyyg== X-Gm-Message-State: AO0yUKXvriD8+4aol8oGHXC4Nd1EKG5gZDvkV8od1M81GfEUnv6/oUwR UzaDQZKnAPE8boMmq+Kv9JB6KsSDDWhKZjhZUpQ0sQ== X-Google-Smtp-Source: AK7set8tn5g8f1nzJsCoEmhlYLTYLcWgOqV+i+6HP7ciPqBQxGRrr+WTlJy/3Mw0K0myaea7Z/5OWg== X-Received: by 2002:a05:6a00:2d29:b0:5e4:f141:568b with SMTP id fa41-20020a056a002d2900b005e4f141568bmr21850676pfb.3.1678381111226; Thu, 09 Mar 2023 08:58:31 -0800 (PST) Received: from [172.20.4.229] ([50.233.106.125]) by smtp.gmail.com with ESMTPSA id j14-20020a62e90e000000b005a8de0f4c76sm11793147pfh.17.2023.03.09.08.58.30 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 09 Mar 2023 08:58:30 -0800 (PST) Message-ID: Date: Thu, 9 Mar 2023 09:58:30 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux aarch64; rv:102.0) Gecko/20100101 Thunderbird/102.8.0 From: Jens Axboe Subject: =?utf-8?q?=5BPATCH=5D_io=5Furing=3A_silence_variable_=E2=80=98prev?= =?utf-8?q?=E2=80=99_set_but_not_used_warning?= To: io-uring Cc: Vincenzo Palazzo Content-Language: en-US Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org If io_uring.o is built with W=1, it triggers a warning: io_uring/io_uring.c: In function ?__io_submit_flush_completions?: io_uring/io_uring.c:1502:40: warning: variable ?prev? set but not used [-Wunused-but-set-variable] 1502 | struct io_wq_work_node *node, *prev; | ^~~~ which is due to the wq_list_for_each() iterator always keeping a 'prev' variable. Most users need this to remove an entry from a list, for example, but __io_submit_flush_completions() never does that. Add a basic helper that doesn't track prev instead, and use that in that function. Reported-by: Vincenzo Palazzo Signed-off-by: Jens Axboe Reviewed-by: Vincenzo Palazzo --- Resend, not sure if the previous went through... diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index fd1cc35a1c00..722624b6d0dc 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -1499,14 +1499,14 @@ void io_free_batch_list(struct io_ring_ctx *ctx, struct io_wq_work_node *node) static void __io_submit_flush_completions(struct io_ring_ctx *ctx) __must_hold(&ctx->uring_lock) { - struct io_wq_work_node *node, *prev; struct io_submit_state *state = &ctx->submit_state; + struct io_wq_work_node *node; __io_cq_lock(ctx); /* must come first to preserve CQE ordering in failure cases */ if (state->cqes_count) __io_flush_post_cqes(ctx); - wq_list_for_each(node, prev, &state->compl_reqs) { + __wq_list_for_each(node, &state->compl_reqs) { struct io_kiocb *req = container_of(node, struct io_kiocb, comp_list); diff --git a/io_uring/slist.h b/io_uring/slist.h index 7c198a40d5f1..0eb194817242 100644 --- a/io_uring/slist.h +++ b/io_uring/slist.h @@ -3,6 +3,9 @@ #include +#define __wq_list_for_each(pos, head) \ + for (pos = (head)->first; pos; pos = (pos)->next) + #define wq_list_for_each(pos, prv, head) \ for (pos = (head)->first, prv = NULL; pos; prv = pos, pos = (pos)->next) @@ -113,4 +116,4 @@ static inline struct io_wq_work *wq_next_work(struct io_wq_work *work) return container_of(work->list.next, struct io_wq_work, list); } -#endif // INTERNAL_IO_SLIST_H \ No newline at end of file +#endif // INTERNAL_IO_SLIST_H