linux-kernel - [PATCH 1/2] ntb_perf: Delete duplicate dmaengine_unmap_put() call in perf_copy

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Message-ID: <a58d6585-4573-44bd-b315-770ca3a54af6@web.de>
Date: Mon, 23 Sep 2024 11:15:15 +0200
From: Markus Elfring <Markus.Elfring@....de>
To: ntb@...ts.linux.dev, kernel-janitors@...r.kernel.org,
 Allen Hubbe <allenbh@...il.com>, Dave Jiang <dave.jiang@...el.com>,
 Jon Mason <jdmason@...zu.us>, Max Hawking <maxahawking@...nenkinder.org>,
 Serge Semin <fancer.lancer@...il.com>
Cc: LKML <linux-kernel@...r.kernel.org>
Subject: [PATCH 1/2] ntb_perf: Delete duplicate dmaengine_unmap_put() call in
 perf_copy_chunk()

From: Markus Elfring <elfring@...rs.sourceforge.net>
Date: Mon, 23 Sep 2024 10:38:11 +0200

The function call “dmaengine_unmap_put(unmap)” was used in an if branch.
The same call was immediately triggered by a subsequent goto statement.
Thus avoid such a call repetition.

This issue was detected by using the Coccinelle software.

Fixes: 5648e56d03fa ("NTB: ntb_perf: Add full multi-port NTB API support")
Cc: stable@...r.kernel.org

Signed-off-by: Markus Elfring <elfring@...rs.sourceforge.net>
---

I imagine that a single function call “dmaengine_unmap_put(unmap)”
can be sufficient for this use case.
https://elixir.bootlin.com/linux/v6.11/source/drivers/dma/dmaengine.c#L1377

How do you think about to improve resource management any further?


 drivers/ntb/test/ntb_perf.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/ntb/test/ntb_perf.c b/drivers/ntb/test/ntb_perf.c
index 72bc1d017a46..dfd175f79e8f 100644
--- a/drivers/ntb/test/ntb_perf.c
+++ b/drivers/ntb/test/ntb_perf.c
@@ -839,10 +839,8 @@ static int perf_copy_chunk(struct perf_thread *pthr,
 	dma_set_unmap(tx, unmap);

 	ret = dma_submit_error(dmaengine_submit(tx));
-	if (ret) {
-		dmaengine_unmap_put(unmap);
+	if (ret)
 		goto err_free_resource;
-	}

 	dmaengine_unmap_put(unmap);

--
2.46.1