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authorMauro Carvalho Chehab <mchehab@osg.samsung.com>2015-04-21 11:33:03 +0200
committerMauro Carvalho Chehab <mchehab@osg.samsung.com>2015-04-21 14:44:55 +0200
commit64131a87f2aae2ed9e05d8227c5b009ca6c50d98 (patch)
treefdea23fd59216120bf54a48c60ca24489a733f14 /net/rds/send.c
parentMerge branch 'patchwork' into v4l_for_linus (diff)
parentMerge Linus master into drm-next (diff)
downloadlinux-64131a87f2aae2ed9e05d8227c5b009ca6c50d98.tar.xz
linux-64131a87f2aae2ed9e05d8227c5b009ca6c50d98.zip
Merge branch 'drm-next-merged' of git://people.freedesktop.org/~airlied/linux into v4l_for_linus
* 'drm-next-merged' of git://people.freedesktop.org/~airlied/linux: (9717 commits) media-bus: Fixup RGB444_1X12, RGB565_1X16, and YUV8_1X24 media bus format hexdump: avoid warning in test function fs: take i_mutex during prepare_binprm for set[ug]id executables smp: Fix error case handling in smp_call_function_*() iommu-common: Fix PARISC compile-time warnings sparc: Make LDC use common iommu poll management functions sparc: Make sparc64 use scalable lib/iommu-common.c functions Break up monolithic iommu table/lock into finer graularity pools and lock sparc: Revert generic IOMMU allocator. tools/power turbostat: correct dumped pkg-cstate-limit value tools/power turbostat: calculate TSC frequency from CPUID(0x15) on SKL tools/power turbostat: correct DRAM RAPL units on recent Xeon processors tools/power turbostat: Initial Skylake support tools/power turbostat: Use $(CURDIR) instead of $(PWD) and add support for O= option in Makefile tools/power turbostat: modprobe msr, if needed tools/power turbostat: dump MSR_TURBO_RATIO_LIMIT2 tools/power turbostat: use new MSR_TURBO_RATIO_LIMIT names Bluetooth: hidp: Fix regression with older userspace and flags validation config: Enable NEED_DMA_MAP_STATE by default when SWIOTLB is selected perf/x86/intel/pt: Fix and clean up error handling in pt_event_add() ... That solves several merge conflicts: Documentation/DocBook/media/v4l/subdev-formats.xml Documentation/devicetree/bindings/vendor-prefixes.txt drivers/staging/media/mn88473/mn88473.c include/linux/kconfig.h include/uapi/linux/media-bus-format.h The ones at subdev-formats.xml and media-bus-format.h are not trivial. That's why we opted to merge from DRM.
Diffstat (limited to 'net/rds/send.c')
-rw-r--r--net/rds/send.c36
1 files changed, 32 insertions, 4 deletions
diff --git a/net/rds/send.c b/net/rds/send.c
index 42f65d4305c8..e9430f537f9c 100644
--- a/net/rds/send.c
+++ b/net/rds/send.c
@@ -140,8 +140,11 @@ int rds_send_xmit(struct rds_connection *conn)
struct scatterlist *sg;
int ret = 0;
LIST_HEAD(to_be_dropped);
+ int batch_count;
+ unsigned long send_gen = 0;
restart:
+ batch_count = 0;
/*
* sendmsg calls here after having queued its message on the send
@@ -157,6 +160,17 @@ restart:
}
/*
+ * we record the send generation after doing the xmit acquire.
+ * if someone else manages to jump in and do some work, we'll use
+ * this to avoid a goto restart farther down.
+ *
+ * The acquire_in_xmit() check above ensures that only one
+ * caller can increment c_send_gen at any time.
+ */
+ conn->c_send_gen++;
+ send_gen = conn->c_send_gen;
+
+ /*
* rds_conn_shutdown() sets the conn state and then tests RDS_IN_XMIT,
* we do the opposite to avoid races.
*/
@@ -202,6 +216,16 @@ restart:
if (!rm) {
unsigned int len;
+ batch_count++;
+
+ /* we want to process as big a batch as we can, but
+ * we also want to avoid softlockups. If we've been
+ * through a lot of messages, lets back off and see
+ * if anyone else jumps in
+ */
+ if (batch_count >= 1024)
+ goto over_batch;
+
spin_lock_irqsave(&conn->c_lock, flags);
if (!list_empty(&conn->c_send_queue)) {
@@ -357,9 +381,9 @@ restart:
}
}
+over_batch:
if (conn->c_trans->xmit_complete)
conn->c_trans->xmit_complete(conn);
-
release_in_xmit(conn);
/* Nuke any messages we decided not to retransmit. */
@@ -380,10 +404,15 @@ restart:
* If the transport cannot continue (i.e ret != 0), then it must
* call us when more room is available, such as from the tx
* completion handler.
+ *
+ * We have an extra generation check here so that if someone manages
+ * to jump in after our release_in_xmit, we'll see that they have done
+ * some work and we will skip our goto
*/
if (ret == 0) {
smp_mb();
- if (!list_empty(&conn->c_send_queue)) {
+ if (!list_empty(&conn->c_send_queue) &&
+ send_gen == conn->c_send_gen) {
rds_stats_inc(s_send_lock_queue_raced);
goto restart;
}
@@ -920,8 +949,7 @@ static int rds_cmsg_send(struct rds_sock *rs, struct rds_message *rm,
return ret;
}
-int rds_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
- size_t payload_len)
+int rds_sendmsg(struct socket *sock, struct msghdr *msg, size_t payload_len)
{
struct sock *sk = sock->sk;
struct rds_sock *rs = rds_sk_to_rs(sk);