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([216.195.201.23]) by smtp.gmail.com with ESMTPSA id 5a478bee46e88-36ca38d46fcsm9019567eec.13.2026.11.04.08.57.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 04 Nov 2026 08:57:18 -0800 (PST) From: Kunwu Chan To: paulmck@kernel.org, boqun@kernel.org, mathieu.desnoyers@efficios.com, jiangshanlai@gmail.com, corbet@lwn.net, mingo@redhat.com, frederic@kernel.org, neeraj.upadhyay@kernel.org, josh@joshtriplett.org, urezki@gmail.com, dave@stgolabs.net Cc: stern@rowland.harvard.edu, parri.andrea@gmail.com, will@kernel.org, dhowells@redhat.com, j.alglave@ucl.ac.uk, luc.maranget@inria.fr, akiyks@gmail.com, dlustig@nvidia.com, joelagnelf@nvidia.com, skhan@linuxfoundation.org, rdunlap@infradead.org, longman@redhat.com, rostedt@goodmis.org, qiang.zhang@linux.dev, kunwu.chan@gmail.com, brads@mainlining.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, lkmm@lists.linux.dev, linux-doc@vger.kernel.org, rcu@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: [PATCH 13/28] hazptr: Add waiter-enqueue tracepoint Date: Thu, 5 Nov 2026 00:54:31 +0800 Message-ID: <20261104165504.2430480-14-kunwu.chan@gmail.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20261104165504.2430480-1-kunwu.chan@gmail.com> References: <20261104165504.2430480-1-kunwu.chan@gmail.com> X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Production tracepoint fired when hazptr_synchronize() enqueues a waiter onto the scan kthread's pending list. Downstream users include hazptrtorture's staged hot-address scenario, which uses it to confirm enqueue before running its controls. Signed-off-by: Kunwu Chan --- include/trace/events/hazptr.h | 29 +++++++++++++++++++++++++++++ kernel/hazptr.c | 5 +++++ 2 files changed, 34 insertions(+) create mode 100644 include/trace/events/hazptr.h diff --git a/include/trace/events/hazptr.h b/include/trace/events/hazptr.h new file mode 100644 index 000000000000..1eed4c9fd682 --- /dev/null +++ b/include/trace/events/hazptr.h @@ -0,0 +1,29 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM hazptr + +#if !defined(_TRACE_HAZPTR_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_HAZPTR_H + +#include + +TRACE_EVENT(hazptr_waiter_enqueue, + + TP_PROTO(void *addr), + + TP_ARGS(addr), + + TP_STRUCT__entry( + __field(void *, addr) + ), + + TP_fast_assign( + __entry->addr = addr; + ), + + TP_printk("addr=%p", __entry->addr) +); + +#endif /* _TRACE_HAZPTR_H */ + +#include diff --git a/kernel/hazptr.c b/kernel/hazptr.c index 4784df78be4e..16f6e2acaf87 100644 --- a/kernel/hazptr.c +++ b/kernel/hazptr.c @@ -19,6 +19,10 @@ #include #include +#define CREATE_TRACE_POINTS +#include +EXPORT_TRACEPOINT_SYMBOL_GPL(hazptr_waiter_enqueue); + #define HAZPTR_WILDCARD ((void *) 1UL) static DEFINE_MUTEX(hazptr_phase_lock); /* Protect the list phase flip. */ @@ -411,6 +415,7 @@ static void hazptr_synchronize_queued(void *addr) mutex_lock(&hazptr_scan.lock); list_add_tail(&waiter.node, &hazptr_scan.pending); + trace_hazptr_waiter_enqueue(addr); if (!READ_ONCE(hazptr_scan.wakeup)) { WRITE_ONCE(hazptr_scan.wakeup, true); swake_up_one(&hazptr_scan.wq); -- 2.43.0