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[Qemu-devel] [PULL v3 28/38] QSLIST: add lock-free operations
From: |
Stefan Hajnoczi |
Subject: |
[Qemu-devel] [PULL v3 28/38] QSLIST: add lock-free operations |
Date: |
Tue, 13 Jan 2015 13:48:06 +0000 |
From: Paolo Bonzini <address@hidden>
These operations are trivial to implement and do not have ABA problems.
They are enough to implement simple multiple-producer, single consumer
lock-free lists or, as in the next patch, the multiple consumers can
steal a whole batch of elements and process them at their leisure.
Signed-off-by: Paolo Bonzini <address@hidden>
Reviewed-by: Fam Zheng <address@hidden>
Message-id: address@hidden
Signed-off-by: Stefan Hajnoczi <address@hidden>
---
include/qemu/queue.h | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)
diff --git a/include/qemu/queue.h b/include/qemu/queue.h
index 42bcadf..a98eb3a 100644
--- a/include/qemu/queue.h
+++ b/include/qemu/queue.h
@@ -191,8 +191,19 @@ struct {
\
} while (/*CONSTCOND*/0)
#define QSLIST_INSERT_HEAD(head, elm, field) do { \
- (elm)->field.sle_next = (head)->slh_first; \
- (head)->slh_first = (elm); \
+ (elm)->field.sle_next = (head)->slh_first; \
+ (head)->slh_first = (elm); \
+} while (/*CONSTCOND*/0)
+
+#define QSLIST_INSERT_HEAD_ATOMIC(head, elm, field) do { \
+ do { \
+ (elm)->field.sle_next = (head)->slh_first; \
+ } while (atomic_cmpxchg(&(head)->slh_first, (elm)->field.sle_next, \
+ (elm)) != (elm)->field.sle_next); \
+} while (/*CONSTCOND*/0)
+
+#define QSLIST_MOVE_ATOMIC(dest, src) do { \
+ (dest)->slh_first = atomic_xchg(&(src)->slh_first, NULL); \
} while (/*CONSTCOND*/0)
#define QSLIST_REMOVE_HEAD(head, field) do { \
--
2.1.0
- [Qemu-devel] [PULL v3 19/38] migration/block: fix pending() return value, (continued)
- [Qemu-devel] [PULL v3 19/38] migration/block: fix pending() return value, Stefan Hajnoczi, 2015/01/13
- [Qemu-devel] [PULL v3 22/38] qemu-iotests: Replace "/bin/true" with "true", Stefan Hajnoczi, 2015/01/13
- [Qemu-devel] [PULL v3 23/38] qemu-iotests: Add "_supported_os Linux" to 058, Stefan Hajnoczi, 2015/01/13
- [Qemu-devel] [PULL v3 20/38] libqos: Convert malloc-pc allocator to a generic allocator, Stefan Hajnoczi, 2015/01/13
- [Qemu-devel] [PULL v3 25/38] coroutine-ucontext: use __thread, Stefan Hajnoczi, 2015/01/13
- [Qemu-devel] [PULL v3 24/38] qemu-iotests: Add supported os parameter for python tests, Stefan Hajnoczi, 2015/01/13
- [Qemu-devel] [PULL v3 26/38] qemu-thread: add per-thread atexit functions, Stefan Hajnoczi, 2015/01/13
- [Qemu-devel] [PULL v3 29/38] coroutine: rewrite pool to avoid mutex, Stefan Hajnoczi, 2015/01/13
- [Qemu-devel] [PULL v3 30/38] coroutine: drop qemu_coroutine_adjust_pool_size, Stefan Hajnoczi, 2015/01/13
- [Qemu-devel] [PULL v3 27/38] test-coroutine: avoid overflow on 32-bit systems, Stefan Hajnoczi, 2015/01/13
- [Qemu-devel] [PULL v3 28/38] QSLIST: add lock-free operations,
Stefan Hajnoczi <=
- [Qemu-devel] [PULL v3 32/38] block: limited request size in write zeroes unsupported path, Stefan Hajnoczi, 2015/01/13
- [Qemu-devel] [PULL v3 33/38] block: Split BLOCK_OP_TYPE_COMMIT to BLOCK_OP_TYPE_COMMIT_{SOURCE, TARGET}, Stefan Hajnoczi, 2015/01/13
- [Qemu-devel] [PULL v3 31/38] coroutine: try harder not to delete coroutines, Stefan Hajnoczi, 2015/01/13
- [Qemu-devel] [PULL v3 34/38] ide: Implement VPD response for ATAPI, Stefan Hajnoczi, 2015/01/13
- [Qemu-devel] [PULL v3 35/38] nvme: Fix get/set number of queues feature, Stefan Hajnoczi, 2015/01/13
- [Qemu-devel] [PULL v3 38/38] NVMe: Set correct VS Value for 1.1 Compliant Controllers, Stefan Hajnoczi, 2015/01/13
- [Qemu-devel] [PULL v3 36/38] MAINTAINERS: Update email addresses for Chrysostomos Nanakos, Stefan Hajnoczi, 2015/01/13
- [Qemu-devel] [PULL v3 37/38] MAINTAINERS: Add migration/block* to block subsystem, Stefan Hajnoczi, 2015/01/13
- Re: [Qemu-devel] [PULL v3 00/38] Block patches, Peter Maydell, 2015/01/13