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From: Steven Rostedt <rostedt@kernel.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>
Subject: [PATCH v2 1/2] tracing: Do not clean up hiter in mmiotrace read function
Date: Thu, 10 Sep 2026 16:24:22 -0400	[thread overview]
Message-ID: <20260910202528.506843293@kernel.org> (raw)
In-Reply-To: 20260910202421.612273038@kernel.org

From: Steven Rostedt <rostedt@goodmis.org>

When the mmiotrace trace was first created, it allocated a descriptor in
its pipe_open() method. Since there was no pipe_close() method when it was
created (in May of 2008, and pipe_close() was added in December of 2009),
it cleaned up the allocated descriptors in the read.

Now that the clean up is in the pipe_close() method that now exists,
remove the clean up from the read as it is no longer needed.

Link: https://lore.kernel.org/all/20260715143604.14481-1-gaikwad.dcg@gmail.com/
Link: https://lore.kernel.org/all/20260721211143.36dbd559@gandalf.local.home/

Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
Changses since v1 : https://patch.msgid.link/20260721212010.76e9ed61@gandalf.local.home

- Broke it up into two patches

 kernel/trace/trace_mmiotrace.c | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c
index 77120d467e11..0034d6af3d9d 100644
--- a/kernel/trace/trace_mmiotrace.c
+++ b/kernel/trace/trace_mmiotrace.c
@@ -152,11 +152,6 @@ static ssize_t mmio_read(struct trace_iterator *iter, struct file *filp,
 	mmio_print_pcidev(s, hiter->dev);
 	hiter->dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, hiter->dev);
 
-	if (!hiter->dev) {
-		destroy_header_iter(hiter);
-		iter->private = NULL;
-	}
-
 print_out:
 	ret = trace_seq_to_user(s, ubuf, cnt);
 	return (ret == -EBUSY) ? 0 : ret;
-- 
2.53.0



  reply	other threads:[~2026-09-10 20:24 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-09-10 20:24 [PATCH v2 0/2] tracing: Do not clean up hiter in mmiotrace read function Steven Rostedt
2026-09-10 20:24 ` Steven Rostedt [this message]
2026-09-10 20:24 ` [PATCH v2 2/2] tracing: Invert the logic in mmio_read() to get rid of the goto Steven Rostedt

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