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[46.135.95.94]) by smtp.gmail.com with ESMTPSA id 4fb4d7f45d1cf-5dcf9f6fa69sm1121849a12.73.2025.02.06.08.44.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 06 Feb 2025 08:44:53 -0800 (PST) From: Mateusz Guzik To: ebiederm@xmission.com, oleg@redhat.com Cc: brauner@kernel.org, akpm@linux-foundation.org, Liam.Howlett@oracle.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Mateusz Guzik Subject: [PATCH v6 5/5] pid: drop irq disablement around pidmap_lock Date: Thu, 6 Feb 2025 17:44:14 +0100 Message-ID: <20250206164415.450051-6-mjguzik@gmail.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20250206164415.450051-1-mjguzik@gmail.com> References: <20250206164415.450051-1-mjguzik@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" It no longer serves any purpose now that the tasklist_lock -> pidmap_lock ordering got eliminated. Reviewed-by: Oleg Nesterov Signed-off-by: Mateusz Guzik --- kernel/pid.c | 23 +++++++++++------------ 1 file changed, 11 insertions(+), 12 deletions(-) diff --git a/kernel/pid.c b/kernel/pid.c index 73625f28c166..900193de4232 100644 --- a/kernel/pid.c +++ b/kernel/pid.c @@ -115,11 +115,10 @@ static void delayed_put_pid(struct rcu_head *rhp) void free_pid(struct pid *pid) { int i; - unsigned long flags; =20 lockdep_assert_not_held(&tasklist_lock); =20 - spin_lock_irqsave(&pidmap_lock, flags); + spin_lock(&pidmap_lock); for (i =3D 0; i <=3D pid->level; i++) { struct upid *upid =3D pid->numbers + i; struct pid_namespace *ns =3D upid->ns; @@ -142,7 +141,7 @@ void free_pid(struct pid *pid) idr_remove(&ns->idr, upid->nr); } pidfs_remove_pid(pid); - spin_unlock_irqrestore(&pidmap_lock, flags); + spin_unlock(&pidmap_lock); =20 call_rcu(&pid->rcu, delayed_put_pid); } @@ -210,7 +209,7 @@ struct pid *alloc_pid(struct pid_namespace *ns, pid_t *= set_tid, } =20 idr_preload(GFP_KERNEL); - spin_lock_irq(&pidmap_lock); + spin_lock(&pidmap_lock); =20 if (tid) { nr =3D idr_alloc(&tmp->idr, NULL, tid, @@ -237,7 +236,7 @@ struct pid *alloc_pid(struct pid_namespace *ns, pid_t *= set_tid, nr =3D idr_alloc_cyclic(&tmp->idr, NULL, pid_min, pid_max, GFP_ATOMIC); } - spin_unlock_irq(&pidmap_lock); + spin_unlock(&pidmap_lock); idr_preload_end(); =20 if (nr < 0) { @@ -271,7 +270,7 @@ struct pid *alloc_pid(struct pid_namespace *ns, pid_t *= set_tid, =20 upid =3D pid->numbers + ns->level; idr_preload(GFP_KERNEL); - spin_lock_irq(&pidmap_lock); + spin_lock(&pidmap_lock); if (!(ns->pid_allocated & PIDNS_ADDING)) goto out_unlock; pidfs_add_pid(pid); @@ -280,18 +279,18 @@ struct pid *alloc_pid(struct pid_namespace *ns, pid_t= *set_tid, idr_replace(&upid->ns->idr, pid, upid->nr); upid->ns->pid_allocated++; } - spin_unlock_irq(&pidmap_lock); + spin_unlock(&pidmap_lock); idr_preload_end(); =20 return pid; =20 out_unlock: - spin_unlock_irq(&pidmap_lock); + spin_unlock(&pidmap_lock); idr_preload_end(); put_pid_ns(ns); =20 out_free: - spin_lock_irq(&pidmap_lock); + spin_lock(&pidmap_lock); while (++i <=3D ns->level) { upid =3D pid->numbers + i; idr_remove(&upid->ns->idr, upid->nr); @@ -301,7 +300,7 @@ struct pid *alloc_pid(struct pid_namespace *ns, pid_t *= set_tid, if (ns->pid_allocated =3D=3D PIDNS_ADDING) idr_set_cursor(&ns->idr, 0); =20 - spin_unlock_irq(&pidmap_lock); + spin_unlock(&pidmap_lock); =20 kmem_cache_free(ns->pid_cachep, pid); return ERR_PTR(retval); @@ -309,9 +308,9 @@ struct pid *alloc_pid(struct pid_namespace *ns, pid_t *= set_tid, =20 void disable_pid_allocation(struct pid_namespace *ns) { - spin_lock_irq(&pidmap_lock); + spin_lock(&pidmap_lock); ns->pid_allocated &=3D ~PIDNS_ADDING; - spin_unlock_irq(&pidmap_lock); + spin_unlock(&pidmap_lock); } =20 struct pid *find_pid_ns(int nr, struct pid_namespace *ns) --=20 2.43.0