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From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Alexei Starovoitov <alexei.starovoitov@gmail.com>,
	Florent Revest <revest@chromium.org>,
	Martin KaFai Lau <martin.lau@linux.dev>,
	bpf <bpf@vger.kernel.org>, Sven Schnelle <svens@linux.ibm.com>,
	Alexei Starovoitov <ast@kernel.org>, Jiri Olsa <jolsa@kernel.org>,
	Arnaldo Carvalho de Melo <acme@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Alan Maguire <alan.maguire@oracle.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Thomas Gleixner <tglx@linutronix.de>, Guo Ren <guoren@kernel.org>
Subject: [PATCH 19/20] function_graph: Use for_each_set_bit() in __ftrace_return_to_handler()
Date: Fri, 24 May 2024 22:37:11 -0400	[thread overview]
Message-ID: <20240525023744.231570357@goodmis.org> (raw)
In-Reply-To: 20240525023652.903909489@goodmis.org

From: "Steven Rostedt (Google)" <rostedt@goodmis.org>

Instead of iterating through the entire fgraph_array[] and seeing if one
of the bitmap bits are set to know to call the array's retfunc() function,
use for_each_set_bit() on the bitmap itself. This will only iterate for
the number of set bits.

Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
 kernel/trace/fgraph.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c
index 4d503b3e45ad..5e8e13ffcfb6 100644
--- a/kernel/trace/fgraph.c
+++ b/kernel/trace/fgraph.c
@@ -827,11 +827,10 @@ static unsigned long __ftrace_return_to_handler(struct fgraph_ret_regs *ret_regs
 #endif
 
 	bitmap = get_bitmap_bits(current, offset);
-	for (i = 0; i < FGRAPH_ARRAY_SIZE; i++) {
+
+	for_each_set_bit(i, &bitmap, sizeof(bitmap) * BITS_PER_BYTE) {
 		struct fgraph_ops *gops = fgraph_array[i];
 
-		if (!(bitmap & BIT(i)))
-			continue;
 		if (gops == &fgraph_stub)
 			continue;
 
-- 
2.43.0



  parent reply	other threads:[~2024-05-25  2:36 UTC|newest]

Thread overview: 37+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-05-25  2:36 [PATCH 00/20] function_graph: Allow multiple users for function graph tracing Steven Rostedt
2024-05-25  2:36 ` [PATCH 01/20] function_graph: Convert ret_stack to a series of longs Steven Rostedt
2024-05-25  2:36 ` [PATCH 02/20] fgraph: Use BUILD_BUG_ON() to make sure we have structures divisible by long Steven Rostedt
2024-05-25  2:36 ` [PATCH 03/20] function_graph: Add an array structure that will allow multiple callbacks Steven Rostedt
2024-05-25  2:36 ` [PATCH 04/20] function_graph: Allow multiple users to attach to function graph Steven Rostedt
2024-05-27  0:34   ` Masami Hiramatsu
2024-05-27  1:17     ` Steven Rostedt
2024-05-25  2:36 ` [PATCH 05/20] function_graph: Handle tail calls for stack unwinding Steven Rostedt
2024-05-25  2:36 ` [PATCH 06/20] function_graph: Remove logic around ftrace_graph_entry and return Steven Rostedt
2024-05-25  2:36 ` [PATCH 07/20] ftrace/function_graph: Pass fgraph_ops to function graph callbacks Steven Rostedt
2024-05-25  2:37 ` [PATCH 08/20] ftrace: Allow function_graph tracer to be enabled in instances Steven Rostedt
2024-05-25  2:37 ` [PATCH 09/20] ftrace: Allow ftrace startup flags to exist without dynamic ftrace Steven Rostedt
2024-05-25  2:37 ` [PATCH 10/20] function_graph: Have the instances use their own ftrace_ops for filtering Steven Rostedt
2024-05-31  2:30   ` Steven Rostedt
2024-05-31  3:12     ` Masami Hiramatsu
2024-05-31  6:03       ` Steven Rostedt
2024-05-31 14:50         ` Masami Hiramatsu
2024-05-31 22:49           ` Steven Rostedt
2024-06-01 19:19             ` Steven Rostedt
2024-06-02  2:40             ` Masami Hiramatsu
2024-05-25  2:37 ` [PATCH 11/20] function_graph: Use a simple LRU for fgraph_array index number Steven Rostedt
2024-05-25  2:37 ` [PATCH 12/20] function_graph: Add "task variables" per task for fgraph_ops Steven Rostedt
2024-05-25  2:37 ` [PATCH 13/20] function_graph: Move set_graph_function tests to shadow stack global var Steven Rostedt
2024-05-25  2:37 ` [PATCH 14/20] function_graph: Move graph depth stored data " Steven Rostedt
2024-05-25  2:37 ` [PATCH 15/20] function_graph: Move graph notrace bit " Steven Rostedt
2024-05-25  2:37 ` [PATCH 16/20] function_graph: Implement fgraph_reserve_data() and fgraph_retrieve_data() Steven Rostedt
2024-05-25  2:37 ` [PATCH 17/20] function_graph: Add selftest for passing local variables Steven Rostedt
2024-05-25  2:37 ` [PATCH 18/20] ftrace: Add multiple fgraph storage selftest Steven Rostedt
2024-05-25  2:37 ` Steven Rostedt [this message]
2024-05-26 23:58   ` [PATCH 19/20] function_graph: Use for_each_set_bit() in __ftrace_return_to_handler() Masami Hiramatsu
2024-05-27  0:04   ` Masami Hiramatsu
2024-05-27  0:32     ` Steven Rostedt
2024-05-25  2:37 ` [PATCH 20/20] function_graph: Use bitmask to loop on fgraph entry Steven Rostedt
2024-05-27  0:09   ` Masami Hiramatsu
2024-05-27  0:33     ` Steven Rostedt
2024-05-27  0:37 ` [PATCH 00/20] function_graph: Allow multiple users for function graph tracing Masami Hiramatsu
2024-05-27  1:18   ` Steven Rostedt

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