From: NeilBrown <neilb@suse.com>
To: Shaohua Li <shli@kernel.org>
Cc: linux-raid@vger.kernel.org, hch@lst.de
Subject: [md PATCH 14/15] percpu-refcount: support synchronous switch to atomic mode.
Date: Wed, 15 Mar 2017 14:05:14 +1100 [thread overview]
Message-ID: <148954711451.18641.16530335727683897485.stgit@noble> (raw)
In-Reply-To: <148954692173.18641.1294690639716682540.stgit@noble>
percpu_ref_switch_to_atomic_sync() schedules the switch
to atomic mode, then waits for it to complete.
Also export percpu_ref_switch_to_* so they can be used from modules.
Signed-off-by: NeilBrown <neilb@suse.com>
---
include/linux/percpu-refcount.h | 1 +
lib/percpu-refcount.c | 18 ++++++++++++++++++
2 files changed, 19 insertions(+)
diff --git a/include/linux/percpu-refcount.h b/include/linux/percpu-refcount.h
index 3a481a49546e..c13dceb87b60 100644
--- a/include/linux/percpu-refcount.h
+++ b/include/linux/percpu-refcount.h
@@ -99,6 +99,7 @@ int __must_check percpu_ref_init(struct percpu_ref *ref,
void percpu_ref_exit(struct percpu_ref *ref);
void percpu_ref_switch_to_atomic(struct percpu_ref *ref,
percpu_ref_func_t *confirm_switch);
+void percpu_ref_switch_to_atomic_sync(struct percpu_ref *ref);
void percpu_ref_switch_to_percpu(struct percpu_ref *ref);
void percpu_ref_kill_and_confirm(struct percpu_ref *ref,
percpu_ref_func_t *confirm_kill);
diff --git a/lib/percpu-refcount.c b/lib/percpu-refcount.c
index 9ac959ef4cae..d133ed43a375 100644
--- a/lib/percpu-refcount.c
+++ b/lib/percpu-refcount.c
@@ -260,6 +260,23 @@ void percpu_ref_switch_to_atomic(struct percpu_ref *ref,
spin_unlock_irqrestore(&percpu_ref_switch_lock, flags);
}
+EXPORT_SYMBOL_GPL(percpu_ref_switch_to_atomic);
+
+/**
+ * percpu_ref_switch_to_atomic_sync - switch a percpu_ref to atomic mode
+ * @ref: percpu_ref to switch to atomic mode
+ *
+ * Schedule switching the ref to atomic mode, and wait for the
+ * switch to complete. Caller must ensure that no other thread
+ * will switch back to percpu mode.
+ *
+ */
+void percpu_ref_switch_to_atomic_sync(struct percpu_ref *ref)
+{
+ percpu_ref_switch_to_atomic(ref, NULL);
+ wait_event(percpu_ref_switch_waitq, !ref->confirm_switch);
+}
+EXPORT_SYMBOL_GPL(percpu_ref_switch_to_atomic_sync);
/**
* percpu_ref_switch_to_percpu - switch a percpu_ref to percpu mode
@@ -290,6 +307,7 @@ void percpu_ref_switch_to_percpu(struct percpu_ref *ref)
spin_unlock_irqrestore(&percpu_ref_switch_lock, flags);
}
+EXPORT_SYMBOL_GPL(percpu_ref_switch_to_percpu);
/**
* percpu_ref_kill_and_confirm - drop the initial ref and schedule confirmation
next prev parent reply other threads:[~2017-03-15 3:05 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-15 3:05 [md PATCH 00/15 v2] remove all abuse of bi_phys_segments NeilBrown
2017-03-15 3:05 ` [md PATCH 02/15] md/raid5: simplfy delaying of writes while metadata is updated NeilBrown
2017-03-15 23:03 ` Shaohua Li
2017-03-16 2:45 ` NeilBrown
2017-03-22 1:40 ` Fix bug in " NeilBrown
2017-03-22 2:29 ` REALLY " NeilBrown
2017-03-22 2:35 ` NeilBrown
2017-03-23 2:22 ` Shaohua Li
2017-03-15 3:05 ` [md PATCH 04/15] block: trace completion of all bios NeilBrown
2017-03-15 3:05 ` [md PATCH 03/15] md/raid5: call bio_endio() directly rather than queueing for later NeilBrown
2017-03-15 3:05 ` [md PATCH 01/15] md/raid5: use md_write_start to count stripes, not bios NeilBrown
2017-03-15 3:05 ` [md PATCH 09/15] md/raid10: stop using bi_phys_segments NeilBrown
2017-03-15 3:05 ` [md PATCH 08/15] md/raid1, raid10: move rXbio accounting closer to allocation NeilBrown
2017-03-15 3:05 ` [md PATCH 06/15] md/raid5: remove over-loading of ->bi_phys_segments NeilBrown
2017-03-15 3:05 ` [md PATCH 07/15] Revert "md/raid5: limit request size according to implementation limits" NeilBrown
2017-03-15 3:05 ` [md PATCH 05/15] md/raid5: use bio_inc_remaining() instead of repurposing bi_phys_segments as a counter NeilBrown
2017-03-15 3:05 ` [md PATCH 11/15] md/raid5: don't test ->writes_pending in raid5_remove_disk NeilBrown
2017-03-15 3:05 ` NeilBrown [this message]
2017-03-15 3:05 ` [md PATCH 10/15] md/raid1: stop using bi_phys_segment NeilBrown
2017-03-16 0:13 ` Shaohua Li
2017-03-16 2:49 ` NeilBrown
2017-03-16 3:36 ` Shaohua Li
2017-03-22 1:41 ` Fix bugs in " NeilBrown
2017-03-15 3:05 ` [md PATCH 13/15] md: close a race with setting mddev->in_sync NeilBrown
2017-03-15 3:05 ` [md PATCH 15/15] MD: use per-cpu counter for writes_pending NeilBrown
2017-03-16 1:05 ` Shaohua Li
2017-03-16 2:57 ` NeilBrown
2017-03-22 1:55 ` Improvement for " NeilBrown
2017-03-22 2:34 ` IMPROVEMENT for " NeilBrown
2017-03-15 3:05 ` [md PATCH 12/15] md: factor out set_in_sync() NeilBrown
2017-03-16 1:12 ` [md PATCH 00/15 v2] remove all abuse of bi_phys_segments Shaohua Li
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