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From:   Vincent Mailhol <mailhol.vincent@wanadoo.fr>
To:     Marc Kleine-Budde <mkl@pengutronix.de>, linux-can@vger.kernel.org,
        linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
        Tom Herbert <therbert@google.com>,
        Eric Dumazet <eric.dumazet@gmail.com>
Cc:     Peter Zijlstra <peterz@infradead.org>,
        Randy Dunlap <rdunlap@infradead.org>,
        Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Subject: [RFC PATCH 1/1] dql: add dql_set_min_limit()
Date:   Wed, 10 Mar 2021 00:23:54 +0900
Message-Id: <20210309152354.95309-2-mailhol.vincent@wanadoo.fr>
In-Reply-To: <20210309152354.95309-1-mailhol.vincent@wanadoo.fr>
References: <20210309152354.95309-1-mailhol.vincent@wanadoo.fr>
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Add a function to set the dynamic queue limit minimum value.

This function is to be used by network drivers which are able to
prove, at least through empirical tests, that they reach better
performances with a specific predefined dql.min_limit value.

Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
---
 include/linux/dynamic_queue_limits.h | 3 +++
 lib/dynamic_queue_limits.c           | 8 ++++++++
 2 files changed, 11 insertions(+)

diff --git a/include/linux/dynamic_queue_limits.h b/include/linux/dynamic_queue_limits.h
index 407c2f281b64..32437f168a35 100644
--- a/include/linux/dynamic_queue_limits.h
+++ b/include/linux/dynamic_queue_limits.h
@@ -103,6 +103,9 @@ void dql_reset(struct dql *dql);
 /* Initialize dql state */
 void dql_init(struct dql *dql, unsigned int hold_time);
 
+/* Set the dql minimum limit */
+void dql_set_min_limit(struct dql *dql, unsigned int min_limit);
+
 #endif /* _KERNEL_ */
 
 #endif /* _LINUX_DQL_H */
diff --git a/lib/dynamic_queue_limits.c b/lib/dynamic_queue_limits.c
index fde0aa244148..8b6ad1e0a2e3 100644
--- a/lib/dynamic_queue_limits.c
+++ b/lib/dynamic_queue_limits.c
@@ -136,3 +136,11 @@ void dql_init(struct dql *dql, unsigned int hold_time)
 	dql_reset(dql);
 }
 EXPORT_SYMBOL(dql_init);
+
+void dql_set_min_limit(struct dql *dql, unsigned int min_limit)
+{
+#ifdef CONFIG_BQL
+	dql->min_limit = min_limit;
+#endif
+}
+EXPORT_SYMBOL(dql_set_min_limit);
-- 
2.26.2