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[141.239.144.21]) by smtp.gmail.com with ESMTPSA id u17-20020a170902a61100b001d6f8b31ddcsm6703203plq.3.2024.01.30.01.13.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 30 Jan 2024 01:13:10 -0800 (PST) Sender: Tejun Heo From: Tejun Heo To: torvalds@linux-foundation.org, mpatocka@redhat.com Cc: linux-kernel@vger.kernel.org, dm-devel@lists.linux.dev, msnitzer@redhat.com, ignat@cloudflare.com, damien.lemoal@wdc.com, bob.liu@oracle.com, houtao1@huawei.com, peterz@infradead.org, mingo@kernel.org, netdev@vger.kernel.org, allen.lkml@gmail.com, kernel-team@meta.com, Tejun Heo , Arjan van de Ven Subject: [PATCH 4/8] backtracetest: Convert from tasklet to BH workqueue Date: Mon, 29 Jan 2024 23:11:51 -1000 Message-ID: <20240130091300.2968534-5-tj@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240130091300.2968534-1-tj@kernel.org> References: <20240130091300.2968534-1-tj@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: 1789506680691595668 X-GMAIL-MSGID: 1789506680691595668 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 backtracetest from tasklet to BH workqueue. - Replace "irq" with "bh" in names and message to better reflect what's happening. - Replace completion usage with a flush_work() call. Signed-off-by: Tejun Heo Cc: Arjan van de Ven --- kernel/backtracetest.c | 18 +++++++----------- 1 file changed, 7 insertions(+), 11 deletions(-) diff --git a/kernel/backtracetest.c b/kernel/backtracetest.c index 370217dd7e39..a4181234232b 100644 --- a/kernel/backtracetest.c +++ b/kernel/backtracetest.c @@ -21,24 +21,20 @@ static void backtrace_test_normal(void) dump_stack(); } -static DECLARE_COMPLETION(backtrace_work); - -static void backtrace_test_irq_callback(unsigned long data) +static void backtrace_test_bh_workfn(struct work_struct *work) { dump_stack(); - complete(&backtrace_work); } -static DECLARE_TASKLET_OLD(backtrace_tasklet, &backtrace_test_irq_callback); +static DECLARE_WORK(backtrace_bh_work, &backtrace_test_bh_workfn); -static void backtrace_test_irq(void) +static void backtrace_test_bh(void) { - pr_info("Testing a backtrace from irq context.\n"); + pr_info("Testing a backtrace from BH context.\n"); pr_info("The following trace is a kernel self test and not a bug!\n"); - init_completion(&backtrace_work); - tasklet_schedule(&backtrace_tasklet); - wait_for_completion(&backtrace_work); + queue_work(system_bh_wq, &backtrace_bh_work); + flush_work(&backtrace_bh_work); } #ifdef CONFIG_STACKTRACE @@ -65,7 +61,7 @@ static int backtrace_regression_test(void) pr_info("====[ backtrace testing ]===========\n"); backtrace_test_normal(); - backtrace_test_irq(); + backtrace_test_bh(); backtrace_test_saved(); pr_info("====[ end of backtrace testing ]====\n");