From: Liao Chang <liaochang1@huawei.com>
To: <mhiramat@kernel.org>, <oleg@redhat.com>, <peterz@infradead.org>,
<mingo@redhat.com>, <acme@kernel.org>, <namhyung@kernel.org>,
<mark.rutland@arm.com>, <alexander.shishkin@linux.intel.com>,
<jolsa@kernel.org>, <irogers@google.com>,
<adrian.hunter@intel.com>, <kan.liang@linux.intel.com>
Cc: <linux-kernel@vger.kernel.org>,
<linux-trace-kernel@vger.kernel.org>,
<linux-perf-users@vger.kernel.org>, <bpf@vger.kernel.org>
Subject: [PATCH v3 1/2] uprobes: Remove redundant spinlock in uprobe_deny_signal()
Date: Thu, 15 Aug 2024 01:46:28 +0000 [thread overview]
Message-ID: <20240815014629.2685155-2-liaochang1@huawei.com> (raw)
In-Reply-To: <20240815014629.2685155-1-liaochang1@huawei.com>
Since clearing a bit in thread_info is an atomic operation, the spinlock
is redundant and can be removed, reducing lock contention is good for
performance.
Acked-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Liao Chang <liaochang1@huawei.com>
---
kernel/events/uprobes.c | 2 --
1 file changed, 2 deletions(-)
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index 73cc47708679..76a51a1f51e2 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -1979,9 +1979,7 @@ bool uprobe_deny_signal(void)
WARN_ON_ONCE(utask->state != UTASK_SSTEP);
if (task_sigpending(t)) {
- spin_lock_irq(&t->sighand->siglock);
clear_tsk_thread_flag(t, TIF_SIGPENDING);
- spin_unlock_irq(&t->sighand->siglock);
if (__fatal_signal_pending(t) || arch_uprobe_xol_was_trapped(t)) {
utask->state = UTASK_SSTEP_TRAPPED;
--
2.34.1
next prev parent reply other threads:[~2024-08-15 1:55 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-08-15 1:46 [PATCH v3 0/2] uprobes: Improve scalability by reducing the contention on siglock Liao Chang
2024-08-15 1:46 ` Liao Chang [this message]
2024-10-22 4:01 ` [PATCH v3 1/2] uprobes: Remove redundant spinlock in uprobe_deny_signal() Masami Hiramatsu
2024-08-15 1:46 ` [PATCH v3 2/2] uprobes: Remove the spinlock within handle_singlestep() Liao Chang
2024-10-22 4:01 ` Masami Hiramatsu
2024-09-14 2:53 ` [PATCH v3 0/2] uprobes: Improve scalability by reducing the contention on siglock Liao, Chang
2024-09-15 15:18 ` Oleg Nesterov
2024-09-18 2:05 ` Liao, Chang
2024-10-11 19:34 ` Andrii Nakryiko
2024-10-21 10:43 ` Liao, Chang
2024-10-21 17:18 ` Andrii Nakryiko
2024-10-22 6:18 ` Liao, Chang
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