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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 v2 22/27] function_graph: Use for_each_set_bit() in __ftrace_return_to_handler()
Date: Sat, 01 Jun 2024 23:38:06 -0400	[thread overview]
Message-ID: <20240602033834.670024223@goodmis.org> (raw)
In-Reply-To: 20240602033744.563858532@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>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
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 f207b7ae5f46..0827b67f746d 100644
--- a/kernel/trace/fgraph.c
+++ b/kernel/trace/fgraph.c
@@ -783,11 +783,10 @@ 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:[~2024-06-02  3:37 UTC|newest]

Thread overview: 41+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-06-02  3:37 [PATCH v2 00/27] function_graph: Allow multiple users for function graph tracing Steven Rostedt
2024-06-02  3:37 ` [PATCH v2 01/27] function_graph: Convert ret_stack to a series of longs Steven Rostedt
2024-06-02  3:37 ` [PATCH v2 02/27] fgraph: Use BUILD_BUG_ON() to make sure we have structures divisible by long Steven Rostedt
2024-06-02  3:37 ` [PATCH v2 03/27] function_graph: Add an array structure that will allow multiple callbacks Steven Rostedt
2024-06-02  3:37 ` [PATCH v2 04/27] function_graph: Allow multiple users to attach to function graph Steven Rostedt
2024-06-02  3:37 ` [PATCH v2 05/27] function_graph: Handle tail calls for stack unwinding Steven Rostedt
2024-06-02  3:37 ` [PATCH v2 06/27] function_graph: Remove logic around ftrace_graph_entry and return Steven Rostedt
2024-06-02  3:37 ` [PATCH v2 07/27] ftrace/function_graph: Pass fgraph_ops to function graph callbacks Steven Rostedt
2024-06-02  3:37 ` [PATCH v2 08/27] ftrace: Allow function_graph tracer to be enabled in instances Steven Rostedt
2024-06-02  3:37 ` [PATCH v2 09/27] ftrace: Allow ftrace startup flags to exist without dynamic ftrace Steven Rostedt
2024-06-02  3:37 ` [PATCH v2 10/27] ftrace: Add subops logic to allow one ops to manage many Steven Rostedt
2024-06-03  1:33   ` Masami Hiramatsu
2024-06-03  2:06     ` Steven Rostedt
2024-06-03  2:46       ` Masami Hiramatsu
2024-06-03 14:54         ` Steven Rostedt
2024-06-03 17:05         ` Steven Rostedt
2024-06-02  3:37 ` [PATCH v2 11/27] ftrace: Allow subops filtering to be modified Steven Rostedt
2024-06-03  2:37   ` Masami Hiramatsu
2024-06-03 14:52     ` Steven Rostedt
2024-06-03 23:12       ` Masami Hiramatsu
2024-06-02  3:37 ` [PATCH v2 12/27] function_graph: Have the instances use their own ftrace_ops for filtering Steven Rostedt
2024-06-02  3:37 ` [PATCH v2 13/27] function_graph: Add pid tracing back to function graph tracer Steven Rostedt
2024-06-02  3:37 ` [PATCH v2 14/27] function_graph: Use a simple LRU for fgraph_array index number Steven Rostedt
2024-06-02  3:37 ` [PATCH v2 15/27] function_graph: Add "task variables" per task for fgraph_ops Steven Rostedt
2024-06-02  3:38 ` [PATCH v2 16/27] function_graph: Move set_graph_function tests to shadow stack global var Steven Rostedt
2024-06-02  3:38 ` [PATCH v2 17/27] function_graph: Move graph depth stored data " Steven Rostedt
2024-06-02  3:38 ` [PATCH v2 18/27] function_graph: Move graph notrace bit " Steven Rostedt
2024-06-02  3:38 ` [PATCH v2 19/27] function_graph: Implement fgraph_reserve_data() and fgraph_retrieve_data() Steven Rostedt
2024-06-02  3:38 ` [PATCH v2 20/27] function_graph: Add selftest for passing local variables Steven Rostedt
2024-06-02  3:38 ` [PATCH v2 21/27] ftrace: Add multiple fgraph storage selftest Steven Rostedt
2024-06-02  3:38 ` Steven Rostedt [this message]
2024-06-02  3:38 ` [PATCH v2 23/27] function_graph: Use bitmask to loop on fgraph entry Steven Rostedt
2024-06-02  3:38 ` [PATCH v2 24/27] function_graph: Use static_call and branch to optimize entry function Steven Rostedt
2024-06-03  3:11   ` Masami Hiramatsu
2024-06-03 15:00     ` Steven Rostedt
2024-06-03 15:07       ` Steven Rostedt
2024-06-03 23:08         ` Masami Hiramatsu
2024-06-02  3:38 ` [PATCH v2 25/27] function_graph: Use static_call and branch to optimize return function Steven Rostedt
2024-06-02  3:38 ` [PATCH v2 26/27] selftests/ftrace: Add function_graph tracer to func-filter-pid test Steven Rostedt
2024-06-02  3:38 ` [PATCH v2 27/27] selftests/ftrace: Add fgraph-multi.tc test Steven Rostedt
2024-06-02  3:44 ` [PATCH v2 00/27] function_graph: Allow multiple users for function graph tracing Steven Rostedt

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