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From:   "Zhuo, Qiuxu" <qiuxu.zhuo@intel.com>
To:     Frederic Weisbecker <frederic@kernel.org>,
        "Paul E . McKenney" <paulmck@kernel.org>
CC:     LKML <linux-kernel@vger.kernel.org>, rcu <rcu@vger.kernel.org>,
        "Uladzislau Rezki" <urezki@gmail.com>,
        Neeraj Upadhyay <quic_neeraju@quicinc.com>,
        "Joel Fernandes" <joel@joelfernandes.org>,
        Giovanni Gherdovich <ggherdovich@suse.cz>
Subject: RE: [PATCH 2/9] rcu: Use rcu_segcblist_segempty() instead of open
 coding it
Thread-Topic: [PATCH 2/9] rcu: Use rcu_segcblist_segempty() instead of open
 coding it
Thread-Index: AQHZk6k3sDGxCEkCH06DmunYWk7R9q+IbQkQ
Date:   Tue, 13 Jun 2023 08:44:18 +0000
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References: <20230531101736.12981-1-frederic@kernel.org>
 <20230531101736.12981-3-frederic@kernel.org>
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This patch LGTM. Thanks!

Reviewed-by: Qiuxu Zhuo <qiuxu.zhuo@intel.com>

> From: Frederic Weisbecker <frederic@kernel.org>
> Sent: Wednesday, May 31, 2023 6:17 PM
> To: Paul E . McKenney <paulmck@kernel.org>
> Cc: LKML <linux-kernel@vger.kernel.org>; Frederic Weisbecker
> <frederic@kernel.org>; rcu <rcu@vger.kernel.org>; Uladzislau Rezki
> <urezki@gmail.com>; Neeraj Upadhyay <quic_neeraju@quicinc.com>; Joel
> Fernandes <joel@joelfernandes.org>; Giovanni Gherdovich
> <ggherdovich@suse.cz>
> Subject: [PATCH 2/9] rcu: Use rcu_segcblist_segempty() instead of open
> coding it
>=20
> This makes the code more readable.
>=20
> Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
> ---
>  kernel/rcu/rcu_segcblist.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>=20
> diff --git a/kernel/rcu/rcu_segcblist.c b/kernel/rcu/rcu_segcblist.c inde=
x
> f71fac422c8f..1693ea22ef1b 100644
> --- a/kernel/rcu/rcu_segcblist.c
> +++ b/kernel/rcu/rcu_segcblist.c
> @@ -368,7 +368,7 @@ bool rcu_segcblist_entrain(struct rcu_segcblist *rscl=
p,
>  	smp_mb(); /* Ensure counts are updated before callback is entrained.
> */
>  	rhp->next =3D NULL;
>  	for (i =3D RCU_NEXT_TAIL; i > RCU_DONE_TAIL; i--)
> -		if (rsclp->tails[i] !=3D rsclp->tails[i - 1])
> +		if (!rcu_segcblist_segempty(rsclp, i))
>  			break;
>  	rcu_segcblist_inc_seglen(rsclp, i);
>  	WRITE_ONCE(*rsclp->tails[i], rhp);
> @@ -551,7 +551,7 @@ bool rcu_segcblist_accelerate(struct rcu_segcblist
> *rsclp, unsigned long seq)
>  	 * as their ->gp_seq[] grace-period completion sequence number.
>  	 */
>  	for (i =3D RCU_NEXT_READY_TAIL; i > RCU_DONE_TAIL; i--)
> -		if (rsclp->tails[i] !=3D rsclp->tails[i - 1] &&
> +		if (!rcu_segcblist_segempty(rsclp, i) &&
>  		    ULONG_CMP_LT(rsclp->gp_seq[i], seq))
>  			break;
>=20
> --
> 2.40.1