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AJvYcCWGl15v+zb4fZBvOjun4Yj8ZtmJrawMQEFzUugpf5HB1mSVboGb33nVUpmjqbAJ3RS76+zxiyc+4HMmM5d+fuKlA+txIyaKuTI1tSf4ShfYZFB16wo51JNQ2ZK5HaW6g3uPakStDmJAsVuefOoFMpiz10iXqMvo+g== X-Gm-Message-State: AOJu0YxC+Amu32OG5b2/ZAXAuHcrgVSMJbiVSgqhnwCK5ljUxnXgwMiz +Jg91Rsit1xsB741pTnK/CePHJC08vX5IvGKie4pTM7pG0wSrkg= X-Google-Smtp-Source: AGHT+IGIuqcpUfq3tRIl3Tp+ivSdarRw1h1Pz+NBzSyS6B+Wv1klEWD1UlLYSK6t5b6FwD/aGF7AqA== X-Received: by 2002:a05:6808:16a8:b0:3c3:7e7a:8236 with SMTP id bb40-20020a05680816a800b003c37e7a8236mr846136oib.18.1711562306195; Wed, 27 Mar 2024 10:58:26 -0700 (PDT) Received: from serve.minyard.net ([47.184.181.2]) by smtp.gmail.com with ESMTPSA id bl16-20020a056808309000b003c3ca856452sm1579224oib.55.2024.03.27.10.58.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 27 Mar 2024 10:58:25 -0700 (PDT) Sender: Corey Minyard Received: from mail.minyard.net (unknown [IPv6:2001:470:b8f6:1b:ac74:4d5d:21e4:a88a]) by serve.minyard.net (Postfix) with ESMTPSA id 6CA7D1800B9; Wed, 27 Mar 2024 17:58:24 +0000 (UTC) Date: Wed, 27 Mar 2024 12:58:23 -0500 From: Corey Minyard To: Allen Pais Cc: linux-kernel@vger.kernel.org, tj@kernel.org, keescook@chromium.org, vkoul@kernel.org, marcan@marcan.st, sven@svenpeter.dev, florian.fainelli@broadcom.com, rjui@broadcom.com, sbranden@broadcom.com, paul@crapouillou.net, Eugeniy.Paltsev@synopsys.com, manivannan.sadhasivam@linaro.org, vireshk@kernel.org, Frank.Li@nxp.com, leoyang.li@nxp.com, zw@zh-kernel.org, wangzhou1@hisilicon.com, haijie1@huawei.com, shawnguo@kernel.org, s.hauer@pengutronix.de, sean.wang@mediatek.com, matthias.bgg@gmail.com, angelogioacchino.delregno@collabora.com, afaerber@suse.de, logang@deltatee.com, daniel@zonque.org, haojian.zhuang@gmail.com, robert.jarzmik@free.fr, andersson@kernel.org, konrad.dybcio@linaro.org, orsonzhai@gmail.com, baolin.wang@linux.alibaba.com, zhang.lyra@gmail.com, patrice.chotard@foss.st.com, linus.walleij@linaro.org, wens@csie.org, jernej.skrabec@gmail.com, peter.ujfalusi@gmail.com, kys@microsoft.com, haiyangz@microsoft.com, wei.liu@kernel.org, decui@microsoft.com, jassisinghbrar@gmail.com, mchehab@kernel.org, maintainers@bluecherrydvr.com, aubin.constans@microchip.com, ulf.hansson@linaro.org, manuel.lauss@gmail.com, mirq-linux@rere.qmqm.pl, jh80.chung@samsung.com, oakad@yahoo.com, hayashi.kunihiko@socionext.com, mhiramat@kernel.org, brucechang@via.com.tw, HaraldWelte@viatech.com, pierre@ossman.eu, duncan.sands@free.fr, stern@rowland.harvard.edu, oneukum@suse.com, openipmi-developer@lists.sourceforge.net, dmaengine@vger.kernel.org, asahi@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-rpi-kernel@lists.infradead.org, linux-mips@vger.kernel.org, imx@lists.linux.dev, linuxppc-dev@lists.ozlabs.org, linux-mediatek@lists.infradead.org, linux-actions@lists.infradead.org, linux-arm-msm@vger.kernel.org, linux-riscv@lists.infradead.org, linux-sunxi@lists.linux.dev, linux-tegra@vger.kernel.org, linux-hyperv@vger.kernel.org, linux-rdma@vger.kernel.org, linux-media@vger.kernel.org, linux-mmc@vger.kernel.org, linux-omap@vger.kernel.org, linux-renesas-soc@vger.kernel.org, linux-s390@vger.kernel.org, netdev@vger.kernel.org, linux-usb@vger.kernel.org Subject: Re: [PATCH 6/9] ipmi: Convert from tasklet to BH workqueue Message-ID: Reply-To: minyard@acm.org References: <20240327160314.9982-1-apais@linux.microsoft.com> <20240327160314.9982-7-apais@linux.microsoft.com> Precedence: bulk X-Mailing-List: imx@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240327160314.9982-7-apais@linux.microsoft.com> On Wed, Mar 27, 2024 at 04:03:11PM +0000, Allen Pais wrote: > The only generic interface to execute asynchronously in the BH context is > tasklet; however, it's marked deprecated and has some design flaws. To > replace tasklets, BH workqueue support was recently added. A BH workqueue > behaves similarly to regular workqueues except that the queued work items > are executed in the BH context. > > This patch converts drivers/infiniband/* from tasklet to BH workqueue. I think you mean drivers/char/ipmi/* here. I believe that work queues items are execute single-threaded for a work queue, so this should be good. I need to test this, though. It may be that an IPMI device can have its own work queue; it may not be important to run it in bh context. -corey > > Based on the work done by Tejun Heo > Branch: https://git.kernel.org/pub/scm/linux/kernel/git/tj/wq.git for-6.10 > > Signed-off-by: Allen Pais > --- > drivers/char/ipmi/ipmi_msghandler.c | 30 ++++++++++++++--------------- > 1 file changed, 15 insertions(+), 15 deletions(-) > > diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c > index b0eedc4595b3..fce2a2dbdc82 100644 > --- a/drivers/char/ipmi/ipmi_msghandler.c > +++ b/drivers/char/ipmi/ipmi_msghandler.c > @@ -36,12 +36,13 @@ > #include > #include > #include > +#include > > #define IPMI_DRIVER_VERSION "39.2" > > static struct ipmi_recv_msg *ipmi_alloc_recv_msg(void); > static int ipmi_init_msghandler(void); > -static void smi_recv_tasklet(struct tasklet_struct *t); > +static void smi_recv_work(struct work_struct *t); > static void handle_new_recv_msgs(struct ipmi_smi *intf); > static void need_waiter(struct ipmi_smi *intf); > static int handle_one_recv_msg(struct ipmi_smi *intf, > @@ -498,13 +499,13 @@ struct ipmi_smi { > /* > * Messages queued for delivery. If delivery fails (out of memory > * for instance), They will stay in here to be processed later in a > - * periodic timer interrupt. The tasklet is for handling received > + * periodic timer interrupt. The work is for handling received > * messages directly from the handler. > */ > spinlock_t waiting_rcv_msgs_lock; > struct list_head waiting_rcv_msgs; > atomic_t watchdog_pretimeouts_to_deliver; > - struct tasklet_struct recv_tasklet; > + struct work_struct recv_work; > > spinlock_t xmit_msgs_lock; > struct list_head xmit_msgs; > @@ -704,7 +705,7 @@ static void clean_up_interface_data(struct ipmi_smi *intf) > struct cmd_rcvr *rcvr, *rcvr2; > struct list_head list; > > - tasklet_kill(&intf->recv_tasklet); > + cancel_work_sync(&intf->recv_work); > > free_smi_msg_list(&intf->waiting_rcv_msgs); > free_recv_msg_list(&intf->waiting_events); > @@ -1319,7 +1320,7 @@ static void free_user(struct kref *ref) > { > struct ipmi_user *user = container_of(ref, struct ipmi_user, refcount); > > - /* SRCU cleanup must happen in task context. */ > + /* SRCU cleanup must happen in work context. */ > queue_work(remove_work_wq, &user->remove_work); > } > > @@ -3605,8 +3606,7 @@ int ipmi_add_smi(struct module *owner, > intf->curr_seq = 0; > spin_lock_init(&intf->waiting_rcv_msgs_lock); > INIT_LIST_HEAD(&intf->waiting_rcv_msgs); > - tasklet_setup(&intf->recv_tasklet, > - smi_recv_tasklet); > + INIT_WORK(&intf->recv_work, smi_recv_work); > atomic_set(&intf->watchdog_pretimeouts_to_deliver, 0); > spin_lock_init(&intf->xmit_msgs_lock); > INIT_LIST_HEAD(&intf->xmit_msgs); > @@ -4779,7 +4779,7 @@ static void handle_new_recv_msgs(struct ipmi_smi *intf) > * To preserve message order, quit if we > * can't handle a message. Add the message > * back at the head, this is safe because this > - * tasklet is the only thing that pulls the > + * work is the only thing that pulls the > * messages. > */ > list_add(&smi_msg->link, &intf->waiting_rcv_msgs); > @@ -4812,10 +4812,10 @@ static void handle_new_recv_msgs(struct ipmi_smi *intf) > } > } > > -static void smi_recv_tasklet(struct tasklet_struct *t) > +static void smi_recv_work(struct work_struct *t) > { > unsigned long flags = 0; /* keep us warning-free. */ > - struct ipmi_smi *intf = from_tasklet(intf, t, recv_tasklet); > + struct ipmi_smi *intf = from_work(intf, t, recv_work); > int run_to_completion = intf->run_to_completion; > struct ipmi_smi_msg *newmsg = NULL; > > @@ -4866,7 +4866,7 @@ void ipmi_smi_msg_received(struct ipmi_smi *intf, > > /* > * To preserve message order, we keep a queue and deliver from > - * a tasklet. > + * a work. > */ > if (!run_to_completion) > spin_lock_irqsave(&intf->waiting_rcv_msgs_lock, flags); > @@ -4887,9 +4887,9 @@ void ipmi_smi_msg_received(struct ipmi_smi *intf, > spin_unlock_irqrestore(&intf->xmit_msgs_lock, flags); > > if (run_to_completion) > - smi_recv_tasklet(&intf->recv_tasklet); > + smi_recv_work(&intf->recv_work); > else > - tasklet_schedule(&intf->recv_tasklet); > + queue_work(system_bh_wq, &intf->recv_work); > } > EXPORT_SYMBOL(ipmi_smi_msg_received); > > @@ -4899,7 +4899,7 @@ void ipmi_smi_watchdog_pretimeout(struct ipmi_smi *intf) > return; > > atomic_set(&intf->watchdog_pretimeouts_to_deliver, 1); > - tasklet_schedule(&intf->recv_tasklet); > + queue_work(system_bh_wq, &intf->recv_work); > } > EXPORT_SYMBOL(ipmi_smi_watchdog_pretimeout); > > @@ -5068,7 +5068,7 @@ static bool ipmi_timeout_handler(struct ipmi_smi *intf, > flags); > } > > - tasklet_schedule(&intf->recv_tasklet); > + queue_work(system_bh_wq, &intf->recv_work); > > return need_timer; > } > -- > 2.17.1 > >