From: Waiman Long <longman@redhat.com>
To: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Jonathan Corbet <corbet@lwn.net>
Cc: linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org,
Arnaldo Carvalho de Melo <acme@kernel.org>,
Davidlohr Bueso <dave@stgolabs.net>,
Mike Galbraith <umgwanakikbuti@gmail.com>,
Scott J Norton <scott.norton@hpe.com>,
Waiman Long <longman@redhat.com>
Subject: [PATCH-tip v5 07/21] futex: Add a new futex type field into futex_state
Date: Fri, 3 Feb 2017 13:03:40 -0500 [thread overview]
Message-ID: <1486145034-22210-8-git-send-email-longman@redhat.com> (raw)
In-Reply-To: <1486145034-22210-1-git-send-email-longman@redhat.com>
As the futex_state structure will be overloaded in later patches
to be used by non-PI futexes, it is necessary to add a type field to
distinguish among different types of futexes.
Signed-off-by: Waiman Long <longman@redhat.com>
---
kernel/futex.c | 15 +++++++++++----
1 file changed, 11 insertions(+), 4 deletions(-)
diff --git a/kernel/futex.c b/kernel/futex.c
index 25881e6..928212c 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -193,6 +193,10 @@
#define FLAGS_CLOCKRT 0x02
#define FLAGS_HAS_TIMEOUT 0x04
+enum futex_type {
+ TYPE_PI = 0,
+};
+
/*
* Futex state object:
* - Priority Inheritance state
@@ -212,6 +216,7 @@ struct futex_state {
struct task_struct *owner;
atomic_t refcount;
+ enum futex_type type;
union futex_key key;
};
@@ -905,13 +910,14 @@ static void put_futex_state(struct futex_state *state)
return;
/*
- * If state->owner is NULL, the owner is most probably dying
- * and has cleaned up the futex state already
+ * If state->owner is NULL and the type is TYPE_PI, the owner is
+ * most probably dying and has cleaned up the futex state already.
*/
if (state->owner) {
task_pi_list_del(state, false);
- rt_mutex_proxy_unlock(&state->pi_mutex, state->owner);
+ if (state->type == TYPE_PI)
+ rt_mutex_proxy_unlock(&state->pi_mutex, state->owner);
}
if (current->pi_state_cache)
@@ -1064,7 +1070,7 @@ static int attach_to_pi_state(u32 uval, struct futex_state *pi_state,
/*
* Userspace might have messed up non-PI and PI futexes [3]
*/
- if (unlikely(!pi_state))
+ if (unlikely(!pi_state || (pi_state->type != TYPE_PI)))
return -EINVAL;
WARN_ON(!atomic_read(&pi_state->refcount));
@@ -1182,6 +1188,7 @@ static int attach_to_pi_owner(u32 uval, union futex_key *key,
/* Store the key for possible exit cleanups: */
pi_state->key = *key;
+ pi_state->type = TYPE_PI;
WARN_ON(!list_empty(&pi_state->list));
list_add(&pi_state->list, &p->pi_state_list);
--
1.8.3.1
next prev parent reply other threads:[~2017-02-03 18:04 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-02-03 18:03 [PATCH-tip v5 00/21] futex: Introducing throughput-optimized (TP) futexes Waiman Long
2017-02-03 18:03 ` [PATCH-tip v5 01/21] perf bench: New microbenchmark for userspace mutex performance Waiman Long
2017-02-03 18:03 ` [PATCH-tip v5 02/21] perf bench: New microbenchmark for userspace rwlock performance Waiman Long
2017-02-03 18:03 ` [PATCH-tip v5 03/21] futex: Consolidate duplicated timer setup code Waiman Long
2017-02-03 18:03 ` [PATCH-tip v5 04/21] futex: Rename futex_pi_state to futex_state Waiman Long
2017-02-03 18:03 ` [PATCH-tip v5 05/21] futex: Add helpers to get & cmpxchg futex value without lock Waiman Long
2017-02-03 18:03 ` [PATCH-tip v5 06/21] futex: Consolidate pure pi_state_list add & delete codes to helpers Waiman Long
2017-02-03 18:03 ` Waiman Long [this message]
2017-02-03 18:03 ` [PATCH-tip v5 08/21] futex: Allow direct attachment of futex_state objects to hash bucket Waiman Long
2017-02-03 18:03 ` [PATCH-tip v5 09/21] futex: Introduce throughput-optimized (TP) futexes Waiman Long
2017-02-03 18:03 ` [PATCH-tip v5 10/21] TP-futex: Enable robust handling Waiman Long
2017-02-03 18:03 ` [PATCH-tip v5 11/21] TP-futex: Implement lock handoff to prevent lock starvation Waiman Long
2017-02-03 18:03 ` [PATCH-tip v5 12/21] TP-futex: Return status code on FUTEX_LOCK calls Waiman Long
2017-02-03 18:03 ` [PATCH-tip v5 13/21] TP-futex: Add timeout support Waiman Long
2017-02-03 18:03 ` [PATCH-tip v5 14/21] TP-futex, doc: Add TP futexes documentation Waiman Long
2017-02-03 18:03 ` [PATCH-tip v5 15/21] TP-futex: Support userspace reader/writer locks Waiman Long
2017-02-03 18:03 ` [PATCH-tip v5 16/21] TP-futex: Enable kernel reader lock stealing Waiman Long
2017-02-03 18:03 ` [PATCH-tip v5 17/21] TP-futex: Group readers together in wait queue Waiman Long
2017-02-03 18:23 ` valdis.kletnieks
2017-02-03 18:42 ` Waiman Long
2017-02-03 19:26 ` valdis.kletnieks
2017-02-03 18:03 ` [PATCH-tip v5 18/21] TP-futex, doc: Update TP futexes document on shared locking Waiman Long
2017-02-03 18:03 ` [PATCH-tip v5 19/21] perf bench: Extend mutex/rwlock futex suite to test TP futexes Waiman Long
2017-02-03 18:03 ` [PATCH-tip v5 20/21] sched, TP-futex: Make wake_up_q() return wakeup count Waiman Long
2017-02-03 18:03 ` [PATCH-tip v5 21/21] futex: Dump internal futex state via debugfs Waiman Long
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