From: Al Viro <viro@ZenIV.linux.org.uk>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
Marc Zyngier <maz@kernel.org>
Subject: [RFC PATCH 14/27] ep_scan_ready_list(): prepare to splitup
Date: Sun, 4 Oct 2020 03:39:16 +0100 [thread overview]
Message-ID: <20201004023929.2740074-14-viro@ZenIV.linux.org.uk> (raw)
In-Reply-To: <20201004023929.2740074-1-viro@ZenIV.linux.org.uk>
From: Al Viro <viro@zeniv.linux.org.uk>
take the stuff done before and after the callback into separate helpers
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
fs/eventpoll.c | 63 +++++++++++++++++++++++++++++++++-------------------------
1 file changed, 36 insertions(+), 27 deletions(-)
diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index e971e3ace557..eb012fdc152e 100644
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -561,28 +561,10 @@ static inline void ep_pm_stay_awake_rcu(struct epitem *epi)
rcu_read_unlock();
}
-/**
- * ep_scan_ready_list - Scans the ready list in a way that makes possible for
- * the scan code, to call f_op->poll(). Also allows for
- * O(NumReady) performance.
- *
- * @ep: Pointer to the epoll private data structure.
- * @sproc: Pointer to the scan callback.
- * @priv: Private opaque data passed to the @sproc callback.
- * @depth: The current depth of recursive f_op->poll calls.
- * @ep_locked: caller already holds ep->mtx
- *
- * Returns: The same integer error code returned by the @sproc callback.
- */
-static __poll_t ep_scan_ready_list(struct eventpoll *ep,
- __poll_t (*sproc)(struct eventpoll *,
- struct list_head *, void *),
- void *priv, int depth, bool ep_locked)
+static void ep_start_scan(struct eventpoll *ep,
+ int depth, bool ep_locked,
+ struct list_head *txlist)
{
- __poll_t res;
- struct epitem *epi, *nepi;
- LIST_HEAD(txlist);
-
lockdep_assert_irqs_enabled();
/*
@@ -602,14 +584,16 @@ static __poll_t ep_scan_ready_list(struct eventpoll *ep,
* in a lockless way.
*/
write_lock_irq(&ep->lock);
- list_splice_init(&ep->rdllist, &txlist);
+ list_splice_init(&ep->rdllist, txlist);
WRITE_ONCE(ep->ovflist, NULL);
write_unlock_irq(&ep->lock);
+}
- /*
- * Now call the callback function.
- */
- res = (*sproc)(ep, &txlist, priv);
+static void ep_done_scan(struct eventpoll *ep,
+ int depth, bool ep_locked,
+ struct list_head *txlist)
+{
+ struct epitem *epi, *nepi;
write_lock_irq(&ep->lock);
/*
@@ -644,13 +628,38 @@ static __poll_t ep_scan_ready_list(struct eventpoll *ep,
/*
* Quickly re-inject items left on "txlist".
*/
- list_splice(&txlist, &ep->rdllist);
+ list_splice(txlist, &ep->rdllist);
__pm_relax(ep->ws);
write_unlock_irq(&ep->lock);
if (!ep_locked)
mutex_unlock(&ep->mtx);
+}
+/**
+ * ep_scan_ready_list - Scans the ready list in a way that makes possible for
+ * the scan code, to call f_op->poll(). Also allows for
+ * O(NumReady) performance.
+ *
+ * @ep: Pointer to the epoll private data structure.
+ * @sproc: Pointer to the scan callback.
+ * @priv: Private opaque data passed to the @sproc callback.
+ * @depth: The current depth of recursive f_op->poll calls.
+ * @ep_locked: caller already holds ep->mtx
+ *
+ * Returns: The same integer error code returned by the @sproc callback.
+ */
+static __poll_t ep_scan_ready_list(struct eventpoll *ep,
+ __poll_t (*sproc)(struct eventpoll *,
+ struct list_head *, void *),
+ void *priv, int depth, bool ep_locked)
+{
+ __poll_t res;
+ LIST_HEAD(txlist);
+
+ ep_start_scan(ep, depth, ep_locked, &txlist);
+ res = (*sproc)(ep, &txlist, priv);
+ ep_done_scan(ep, depth, ep_locked, &txlist);
return res;
}
--
2.11.0
next prev parent reply other threads:[~2020-10-04 2:39 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-04 2:36 [RFC][PATCHSET] epoll cleanups Al Viro
2020-10-04 2:39 ` [RFC PATCH 01/27] epoll: switch epitem->pwqlist to single-linked list Al Viro
2020-10-04 2:39 ` [RFC PATCH 02/27] epoll: get rid of epitem->nwait Al Viro
2020-10-04 2:39 ` [RFC PATCH 03/27] untangling ep_call_nested(): get rid of useless arguments Al Viro
2020-10-04 2:39 ` [RFC PATCH 04/27] untangling ep_call_nested(): it's all serialized on epmutex Al Viro
2020-10-04 2:39 ` [RFC PATCH 05/27] untangling ep_call_nested(): take pushing cookie into a helper Al Viro
2020-10-04 2:39 ` [RFC PATCH 06/27] untangling ep_call_nested(): move push/pop of cookie into the callbacks Al Viro
2020-10-04 2:39 ` [RFC PATCH 07/27] untangling ep_call_nested(): and there was much rejoicing Al Viro
2020-10-04 2:39 ` [RFC PATCH 08/27] reverse_path_check_proc(): sane arguments Al Viro
2020-10-04 2:39 ` [RFC PATCH 09/27] reverse_path_check_proc(): don't bother with cookies Al Viro
2020-10-04 2:39 ` [RFC PATCH 10/27] clean reverse_path_check_proc() a bit Al Viro
2020-10-04 2:39 ` [RFC PATCH 11/27] ep_loop_check_proc(): lift pushing the cookie into callers Al Viro
2020-10-04 2:39 ` [RFC PATCH 12/27] get rid of ep_push_nested() Al Viro
2020-10-04 2:39 ` [RFC PATCH 13/27] ep_loop_check_proc(): saner calling conventions Al Viro
2020-10-04 2:39 ` Al Viro [this message]
2020-10-04 2:39 ` [RFC PATCH 15/27] lift the calls of ep_read_events_proc() into the callers Al Viro
2020-10-04 2:39 ` [RFC PATCH 16/27] lift the calls of ep_send_events_proc() " Al Viro
2020-10-04 2:39 ` [RFC PATCH 17/27] ep_send_events_proc(): fold into the caller Al Viro
2020-10-04 2:39 ` [RFC PATCH 18/27] lift locking/unlocking ep->mtx out of ep_{start,done}_scan() Al Viro
2020-10-04 2:39 ` [RFC PATCH 19/27] ep_insert(): don't open-code ep_remove() on failure exits Al Viro
2020-10-04 2:39 ` [RFC PATCH 20/27] ep_insert(): we only need tep->mtx around the insertion itself Al Viro
2020-10-04 12:56 ` [ep_insert()] 9ee1cc5666: WARNING:possible_recursive_locking_detected kernel test robot
2020-10-04 14:17 ` Al Viro
2020-10-04 14:27 ` Al Viro
2020-10-04 2:39 ` [RFC PATCH 21/27] take the common part of ep_eventpoll_poll() and ep_item_poll() into helper Al Viro
2020-10-04 2:39 ` [RFC PATCH 22/27] fold ep_read_events_proc() into the only caller Al Viro
2020-10-04 2:39 ` [RFC PATCH 23/27] ep_insert(): move creation of wakeup source past the fl_ep_links insertion Al Viro
2020-10-04 2:39 ` [RFC PATCH 24/27] convert ->f_ep_links/->fllink to hlist Al Viro
2020-10-04 2:39 ` [RFC PATCH 25/27] lift rcu_read_lock() into reverse_path_check() Al Viro
2020-10-04 2:39 ` [RFC PATCH 26/27] epoll: massage the check list insertion Al Viro
2020-10-04 2:39 ` [RFC PATCH 27/27] epoll: take epitem list out of struct file Al Viro
2020-10-05 20:37 ` Qian Cai
2020-10-05 20:49 ` Al Viro
2020-10-04 2:49 ` [RFC][PATCHSET] epoll cleanups Al Viro
2020-10-04 12:13 ` Matthew Wilcox
2020-10-04 14:15 ` Al Viro
2020-10-04 18:08 ` Linus Torvalds
2020-10-04 20:05 ` Al Viro
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