From: Leon Romanovsky <leon@kernel.org>
To: Doug Ledford <dledford@redhat.com>, Jason Gunthorpe <jgg@nvidia.com>
Cc: Leon Romanovsky <leonro@mellanox.com>, linux-rdma@vger.kernel.org
Subject: [PATCH rdma-next 11/14] RDMA/ucma: Change backlog into an atomic
Date: Tue, 18 Aug 2020 15:05:23 +0300 [thread overview]
Message-ID: <20200818120526.702120-12-leon@kernel.org> (raw)
In-Reply-To: <20200818120526.702120-1-leon@kernel.org>
From: Jason Gunthorpe <jgg@nvidia.com>
There is no reason to grab the file->mut just to do this inc/dec work. Use
an atomic.
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
---
drivers/infiniband/core/ucma.c | 15 ++++++++-------
1 file changed, 8 insertions(+), 7 deletions(-)
diff --git a/drivers/infiniband/core/ucma.c b/drivers/infiniband/core/ucma.c
index ad78b05de656..8be8ff14ab62 100644
--- a/drivers/infiniband/core/ucma.c
+++ b/drivers/infiniband/core/ucma.c
@@ -88,7 +88,7 @@ struct ucma_context {
struct completion comp;
refcount_t ref;
int events_reported;
- int backlog;
+ atomic_t backlog;
struct ucma_file *file;
struct rdma_cm_id *cm_id;
@@ -348,12 +348,11 @@ static int ucma_event_handler(struct rdma_cm_id *cm_id,
uevent->resp.ece.attr_mod = event->ece.attr_mod;
if (event->event == RDMA_CM_EVENT_CONNECT_REQUEST) {
- if (!ctx->backlog) {
+ if (!atomic_add_unless(&ctx->backlog, -1, 0)) {
ret = -ENOMEM;
kfree(uevent);
goto out;
}
- ctx->backlog--;
} else if (!ctx->uid || ctx->cm_id != cm_id) {
/*
* We ignore events for new connections until userspace has set
@@ -432,7 +431,7 @@ static ssize_t ucma_get_event(struct ucma_file *file, const char __user *inbuf,
}
if (ctx) {
- uevent->ctx->backlog++;
+ atomic_inc(&uevent->ctx->backlog);
uevent->cm_id->context = ctx;
ucma_finish_ctx(ctx);
}
@@ -1136,10 +1135,12 @@ static ssize_t ucma_listen(struct ucma_file *file, const char __user *inbuf,
if (IS_ERR(ctx))
return PTR_ERR(ctx);
- ctx->backlog = cmd.backlog > 0 && cmd.backlog < max_backlog ?
- cmd.backlog : max_backlog;
+ if (cmd.backlog <= 0 || cmd.backlog > max_backlog)
+ cmd.backlog = max_backlog;
+ atomic_set(&ctx->backlog, cmd.backlog);
+
mutex_lock(&ctx->mutex);
- ret = rdma_listen(ctx->cm_id, ctx->backlog);
+ ret = rdma_listen(ctx->cm_id, cmd.backlog);
mutex_unlock(&ctx->mutex);
ucma_put_ctx(ctx);
return ret;
--
2.26.2
next prev parent reply other threads:[~2020-08-18 12:06 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-18 12:05 [PATCH rdma-next 00/14] Cleanup locking and events in ucma Leon Romanovsky
2020-08-18 12:05 ` [PATCH rdma-next 01/14] RDMA/ucma: Fix refcount 0 incr in ucma_get_ctx() Leon Romanovsky
2020-08-18 12:05 ` [PATCH rdma-next 02/14] RDMA/ucma: Remove unnecessary locking of file->ctx_list in close Leon Romanovsky
2020-08-18 12:05 ` [PATCH rdma-next 03/14] RDMA/ucma: Consolidate the two destroy flows Leon Romanovsky
2020-08-18 12:05 ` [PATCH rdma-next 04/14] RDMA/ucma: Fix error cases around ucma_alloc_ctx() Leon Romanovsky
2020-08-18 12:05 ` [PATCH rdma-next 05/14] RDMA/ucma: Remove mc_list and rely on xarray Leon Romanovsky
2020-08-18 12:05 ` [PATCH rdma-next 06/14] RDMA/cma: Add missing locking to rdma_accept() Leon Romanovsky
2021-02-09 14:46 ` Chuck Lever
2021-02-09 15:40 ` Jason Gunthorpe
2020-08-18 12:05 ` [PATCH rdma-next 07/14] RDMA/ucma: Do not use file->mut to lock destroying Leon Romanovsky
2020-08-18 12:05 ` [PATCH rdma-next 08/14] RDMA/ucma: Fix the locking of ctx->file Leon Romanovsky
2020-08-18 12:05 ` [PATCH rdma-next 09/14] RDMA/ucma: Fix locking for ctx->events_reported Leon Romanovsky
2020-08-18 12:05 ` [PATCH rdma-next 10/14] RDMA/ucma: Add missing locking around rdma_leave_multicast() Leon Romanovsky
2020-08-18 12:05 ` Leon Romanovsky [this message]
2020-08-18 12:05 ` [PATCH rdma-next 12/14] RDMA/ucma: Narrow file->mut in ucma_event_handler() Leon Romanovsky
2020-08-18 12:05 ` [PATCH rdma-next 13/14] RDMA/ucma: Rework how new connections are passed through event delivery Leon Romanovsky
2020-08-18 12:05 ` [PATCH rdma-next 14/14] RDMA/ucma: Remove closing and the close_wq Leon Romanovsky
2020-08-27 11:39 ` [PATCH rdma-next 00/14] Cleanup locking and events in ucma Jason Gunthorpe
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