linux-kernel - Re: [PATCH] bnx2x: Replace semaphore stats

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Date:   Thu, 20 Oct 2016 14:27:36 -0400 (EDT)
From:   David Miller <davem@...emloft.net>
To:     binoy.jayan@...aro.org
Cc:     ariel.elior@...gic.com, arnd@...db.de, netdev@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH] bnx2x: Replace semaphore stats_lock with mutex

From: Binoy Jayan <binoy.jayan@...aro.org>
Date: Thu, 20 Oct 2016 14:22:12 +0530

> stats_lock is used as a simple mutex

No, it is not.

> @@ -1976,8 +1973,8 @@ int bnx2x_stats_safe_exec(struct bnx2x *bp,
>  	/* Wait for statistics to end [while blocking further requests],
>  	 * then run supplied function 'safely'.
>  	 */
> -	rc = down_timeout(&bp->stats_lock, HZ / 10);
> -	if (unlikely(rc)) {
> +	rc = mutex_trylock(&bp->stats_lock);
> +	if (unlikely(!rc)) {

It uses timeouts therefore this conversion is not 1 to 1.

You're losing functionality and potentially adding a regression.