From patchwork Fri Apr 21 02:50:29 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tejun Heo X-Patchwork-Id: 676454 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 F1567C77B73 for ; Fri, 21 Apr 2023 02:51:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233734AbjDUCvN (ORCPT ); Thu, 20 Apr 2023 22:51:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43272 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233699AbjDUCvG (ORCPT ); Thu, 20 Apr 2023 22:51:06 -0400 Received: from mail-pj1-x1034.google.com (mail-pj1-x1034.google.com [IPv6:2607:f8b0:4864:20::1034]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2FCD86EB9; Thu, 20 Apr 2023 19:51:01 -0700 (PDT) Received: by mail-pj1-x1034.google.com with SMTP id 98e67ed59e1d1-247122e9845so1180197a91.0; Thu, 20 Apr 2023 19:51:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1682045460; x=1684637460; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:sender:from:to:cc:subject:date :message-id:reply-to; bh=67LgqNT8XF4vwy6yP32eHkU2I1u0Y3vukwyzktySQbU=; b=ZiAbVoUZ8IJAvox8IcFlDfaPh+VjoBXLmk6VAgIov93QLpk2pLax3y6rXcov36Ldwu vpOMojneq8Km6ua5QR8wSfoPVEPpscDPScZeepJ7zfN+3badZWA3SHeJXMjD2pwdkhGb vPeMUQ7KlKoxz1V2kEeNA2ueeYAYmySfRamPHAPEckyonnguEcP0WtfyngHomfQ4alcJ 1PYEaUKSL9FghM7WlQernDRjNWvawyRwvBLatXB/MZENORCKFR+W2Zp7opGS1hMYGR1H Xj4v9NlzxiP+br94U+xXJp6izZ/+DT1OvWx7LelKejYjbPDhd3qUUJipzuxJ03KHGBV+ pUsA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1682045460; x=1684637460; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:sender:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=67LgqNT8XF4vwy6yP32eHkU2I1u0Y3vukwyzktySQbU=; b=cj6ug0K2Lj0LvW3pZooOj8/iE/SHIVL+3D4EKcEjcwc2OFR0+jUpTSr+UoCzbeHPSE Dk3Z1IjIqeYoy8TLjaXs2lrj47vtid2NcwxocdbToeiuFVXVQUcfj0qNT/jq+wo7qhdB LIFWTRLgvoF40umkhVHhbL1o38UNQrxUPWUNwpGkkglPUEwwoxqfsusGcgPicJ68tiEA wKoeyVsLwez0UOjeFcEgwUusK9R9M3QlZstjLTv9N7VPKx0yji1arfVi8VSG2Wox9lqS hV5V94F/iJC8jb0jLsETWcYRDJBS8vcOjFyyTcAgNM+3ox/AT65Gd7uXMN33DXQbsgL5 TbSg== X-Gm-Message-State: AAQBX9cREaDSwj1V+Afk1hvHmFEzmUILZvfo+QDaFjDJCfQeu9jBcWwi LnyOfHEfO7sthaoJbDZ+5OI= X-Google-Smtp-Source: AKy350ZYr+N8r41JuwzmIMgGzxWuOG+gKGnToOJFJc5nn8AIZ3wgdSVHFaVF8j1iwe2ohapy4B4hgw== X-Received: by 2002:a17:90a:d14f:b0:24b:6349:4f87 with SMTP id t15-20020a17090ad14f00b0024b63494f87mr1686085pjw.6.1682045460086; Thu, 20 Apr 2023 19:51:00 -0700 (PDT) Received: from localhost (2603-800c-1a02-1bae-a7fa-157f-969a-4cde.res6.spectrum.com. [2603:800c:1a02:1bae:a7fa:157f:969a:4cde]) by smtp.gmail.com with ESMTPSA id d4-20020a170902b70400b001a681d123a0sm1717302pls.297.2023.04.20.19.50.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 20 Apr 2023 19:50:59 -0700 (PDT) Sender: Tejun Heo From: Tejun Heo To: jiangshanlai@gmail.com Cc: linux-kernel@vger.kernel.org, kernel-team@meta.com, Tejun Heo , Ming Qian , Shijie Qin , Zhou Peng , Mauro Carvalho Chehab , linux-media@vger.kernel.org Subject: [PATCH 05/22] media: amphion: Use alloc_ordered_workqueue() to create ordered workqueues Date: Thu, 20 Apr 2023 16:50:29 -1000 Message-Id: <20230421025046.4008499-6-tj@kernel.org> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230421025046.4008499-1-tj@kernel.org> References: <20230421025046.4008499-1-tj@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org BACKGROUND ========== When multiple work items are queued to a workqueue, their execution order doesn't match the queueing order. They may get executed in any order and simultaneously. When fully serialized execution - one by one in the queueing order - is needed, an ordered workqueue should be used which can be created with alloc_ordered_workqueue(). However, alloc_ordered_workqueue() was a later addition. Before it, an ordered workqueue could be obtained by creating an UNBOUND workqueue with @max_active==1. This originally was an implementation side-effect which was broken by 4c16bd327c74 ("workqueue: restore WQ_UNBOUND/max_active==1 to be ordered"). Because there were users that depended on the ordered execution, 5c0338c68706 ("workqueue: restore WQ_UNBOUND/max_active==1 to be ordered") made workqueue allocation path to implicitly promote UNBOUND workqueues w/ @max_active==1 to ordered workqueues. While this has worked okay, overloading the UNBOUND allocation interface this way creates other issues. It's difficult to tell whether a given workqueue actually needs to be ordered and users that legitimately want a min concurrency level wq unexpectedly gets an ordered one instead. With planned UNBOUND workqueue updates to improve execution locality and more prevalence of chiplet designs which can benefit from such improvements, this isn't a state we wanna be in forever. This patch series audits all callsites that create an UNBOUND workqueue w/ @max_active==1 and converts them to alloc_ordered_workqueue() as necessary. WHAT TO LOOK FOR ================ The conversions are from alloc_workqueue(WQ_UNBOUND | flags, 1, args..) to alloc_ordered_workqueue(flags, args...) which don't cause any functional changes. If you know that fully ordered execution is not ncessary, please let me know. I'll drop the conversion and instead add a comment noting the fact to reduce confusion while conversion is in progress. If you aren't fully sure, it's completely fine to let the conversion through. The behavior will stay exactly the same and we can always reconsider later. As there are follow-up workqueue core changes, I'd really appreciate if the patch can be routed through the workqueue tree w/ your acks. Thanks. Signed-off-by: Tejun Heo Cc: Ming Qian Cc: Shijie Qin Cc: Zhou Peng Cc: Mauro Carvalho Chehab Cc: linux-media@vger.kernel.org --- drivers/media/platform/amphion/vpu_core.c | 2 +- drivers/media/platform/amphion/vpu_v4l2.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/media/platform/amphion/vpu_core.c b/drivers/media/platform/amphion/vpu_core.c index f9ec1753f7c8..57d56c680c07 100644 --- a/drivers/media/platform/amphion/vpu_core.c +++ b/drivers/media/platform/amphion/vpu_core.c @@ -254,7 +254,7 @@ static int vpu_core_register(struct device *dev, struct vpu_core *core) if (vpu_core_is_exist(vpu, core)) return 0; - core->workqueue = alloc_workqueue("vpu", WQ_UNBOUND | WQ_MEM_RECLAIM, 1); + core->workqueue = alloc_ordered_workqueue("vpu", WQ_MEM_RECLAIM); if (!core->workqueue) { dev_err(core->dev, "fail to alloc workqueue\n"); return -ENOMEM; diff --git a/drivers/media/platform/amphion/vpu_v4l2.c b/drivers/media/platform/amphion/vpu_v4l2.c index 6773b885597c..a48edb445eea 100644 --- a/drivers/media/platform/amphion/vpu_v4l2.c +++ b/drivers/media/platform/amphion/vpu_v4l2.c @@ -740,7 +740,7 @@ int vpu_v4l2_open(struct file *file, struct vpu_inst *inst) inst->fh.ctrl_handler = &inst->ctrl_handler; file->private_data = &inst->fh; inst->state = VPU_CODEC_STATE_DEINIT; - inst->workqueue = alloc_workqueue("vpu_inst", WQ_UNBOUND | WQ_MEM_RECLAIM, 1); + inst->workqueue = alloc_ordered_workqueue("vpu_inst", WQ_MEM_RECLAIM); if (inst->workqueue) { INIT_WORK(&inst->msg_work, vpu_inst_run_work); ret = kfifo_init(&inst->msg_fifo, From patchwork Fri Apr 21 02:50:45 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tejun Heo X-Patchwork-Id: 676071 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 26BC9C7618E for ; Fri, 21 Apr 2023 02:52:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234068AbjDUCwk (ORCPT ); Thu, 20 Apr 2023 22:52:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43566 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233750AbjDUCvx (ORCPT ); Thu, 20 Apr 2023 22:51:53 -0400 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 0DF417D84; Thu, 20 Apr 2023 19:51:30 -0700 (PDT) Received: by mail-pf1-x433.google.com with SMTP id d2e1a72fcca58-63b60366047so1513112b3a.1; Thu, 20 Apr 2023 19:51:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1682045489; x=1684637489; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:sender:from:to:cc:subject:date :message-id:reply-to; bh=8AHaFd45rL0q5b4AB3LAX24oOzN6BIEVC1RaqbCPXVU=; b=kilWJuIJweTRgBTwgFCwGu9lFsKgCOqZCxPqrZnLjD1QVK+XFkDNp2XuD+d81qgDhP GbCxA77d9pzcU4CDGX2f32KQ2wxlODcfSZQqzWPbjPQG/XVb4BMk+OoPVaeu8yBqD/nZ tKxdqKZuZ2+JLyTixbOJLEL/V8Oj72FHGk5nMRvlLUjbDuVxhI2GoJtMhWmtLjxTfRc2 7iVSR6lx3r2gH32/oKvSkD9XTXegBICwHtrtzLq3MXu+QT52PIgVSCJZbgy1V/tPKUl6 bt9GvindBpEKhbuYIGtwTF74485YSuFrlxtVVXfCIX+lc6JqiCeks/82b8HKH9024NzJ qY1A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1682045489; x=1684637489; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:sender:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=8AHaFd45rL0q5b4AB3LAX24oOzN6BIEVC1RaqbCPXVU=; b=Z/FoNZ7umK6QzhQo7OrgReDm1S1hOT4gys1wB3jdgO6Wsrv2xTWHsutWThUdnEbwST 4Au30H0tr5WZqi6jBoRdGibax5mcOLFabrOlcLsGwm/ys6w0UcRYOMEYWY851eLAPUOe 93oEhGvX+13xuQkZiQ4ABCC8OLzB44Ss7ZMY7O8rFkmDoVw3UAw1ykvX4CMM9WSG12b9 h0j2xVaCx4ZLb2Qrzh49wciGY69KMOLxDnfMtkpOytn81EMC8piPLvGEeXvwce/ZxNEM 1uGmii5haV84EHpuAVVYgDvmY08vP51Powc6Uc1QsuaXvTBcMWGWETa6i1idyfk2xXA4 /Jjg== X-Gm-Message-State: AAQBX9cCacuF0ByUtkyTUR4eLncD1V96yY6DnWIqGrnyA2jHqRq4O8Gn X2lTCuT1w6H4KB7AMAHXLUUZm6Tmohg= X-Google-Smtp-Source: AKy350br98lwPtK/oCaUCu1Sr/3XVVJszaE3p5fpyg1vr9SLs10BhdO9PcPxNFfj1oMvq0YlikENeA== X-Received: by 2002:a05:6a00:1582:b0:63d:3ddb:5f3f with SMTP id u2-20020a056a00158200b0063d3ddb5f3fmr4982153pfk.0.1682045489387; Thu, 20 Apr 2023 19:51:29 -0700 (PDT) Received: from localhost (2603-800c-1a02-1bae-a7fa-157f-969a-4cde.res6.spectrum.com. [2603:800c:1a02:1bae:a7fa:157f:969a:4cde]) by smtp.gmail.com with ESMTPSA id z21-20020a62d115000000b0063d24fcc2b7sm1908694pfg.1.2023.04.20.19.51.28 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 20 Apr 2023 19:51:29 -0700 (PDT) Sender: Tejun Heo From: Tejun Heo To: jiangshanlai@gmail.com Cc: linux-kernel@vger.kernel.org, kernel-team@meta.com, Tejun Heo , Philipp Zabel , Mauro Carvalho Chehab , linux-media@vger.kernel.org Subject: [PATCH 21/22] media: coda: Use alloc_ordered_workqueue() to create ordered workqueues Date: Thu, 20 Apr 2023 16:50:45 -1000 Message-Id: <20230421025046.4008499-22-tj@kernel.org> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230421025046.4008499-1-tj@kernel.org> References: <20230421025046.4008499-1-tj@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org BACKGROUND ========== When multiple work items are queued to a workqueue, their execution order doesn't match the queueing order. They may get executed in any order and simultaneously. When fully serialized execution - one by one in the queueing order - is needed, an ordered workqueue should be used which can be created with alloc_ordered_workqueue(). However, alloc_ordered_workqueue() was a later addition. Before it, an ordered workqueue could be obtained by creating an UNBOUND workqueue with @max_active==1. This originally was an implementation side-effect which was broken by 4c16bd327c74 ("workqueue: restore WQ_UNBOUND/max_active==1 to be ordered"). Because there were users that depended on the ordered execution, 5c0338c68706 ("workqueue: restore WQ_UNBOUND/max_active==1 to be ordered") made workqueue allocation path to implicitly promote UNBOUND workqueues w/ @max_active==1 to ordered workqueues. While this has worked okay, overloading the UNBOUND allocation interface this way creates other issues. It's difficult to tell whether a given workqueue actually needs to be ordered and users that legitimately want a min concurrency level wq unexpectedly gets an ordered one instead. With planned UNBOUND workqueue updates to improve execution locality and more prevalence of chiplet designs which can benefit from such improvements, this isn't a state we wanna be in forever. This patch series audits all callsites that create an UNBOUND workqueue w/ @max_active==1 and converts them to alloc_ordered_workqueue() as necessary. WHAT TO LOOK FOR ================ The conversions are from alloc_workqueue(WQ_UNBOUND | flags, 1, args..) to alloc_ordered_workqueue(flags, args...) which don't cause any functional changes. If you know that fully ordered execution is not ncessary, please let me know. I'll drop the conversion and instead add a comment noting the fact to reduce confusion while conversion is in progress. If you aren't fully sure, it's completely fine to let the conversion through. The behavior will stay exactly the same and we can always reconsider later. As there are follow-up workqueue core changes, I'd really appreciate if the patch can be routed through the workqueue tree w/ your acks. Thanks. Signed-off-by: Tejun Heo Cc: Philipp Zabel Cc: Mauro Carvalho Chehab Cc: linux-media@vger.kernel.org --- drivers/media/platform/chips-media/coda-common.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/media/platform/chips-media/coda-common.c b/drivers/media/platform/chips-media/coda-common.c index af71eea04dbd..c8ecfe760028 100644 --- a/drivers/media/platform/chips-media/coda-common.c +++ b/drivers/media/platform/chips-media/coda-common.c @@ -3268,7 +3268,7 @@ static int coda_probe(struct platform_device *pdev) &dev->iram.blob); } - dev->workqueue = alloc_workqueue("coda", WQ_UNBOUND | WQ_MEM_RECLAIM, 1); + dev->workqueue = alloc_ordered_workqueue("coda", WQ_MEM_RECLAIM); if (!dev->workqueue) { dev_err(&pdev->dev, "unable to alloc workqueue\n"); ret = -ENOMEM;