From: "Andrea Parri (Microsoft)" <parri.andrea@gmail.com>
To: "K . Y . Srinivasan" <kys@microsoft.com>,
Haiyang Zhang <haiyangz@microsoft.com>,
Stephen Hemminger <sthemmin@microsoft.com>,
Wei Liu <wei.liu@kernel.org>,
Michael Kelley <mikelley@microsoft.com>
Cc: linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org,
"Andrea Parri (Microsoft)" <parri.andrea@gmail.com>
Subject: [PATCH 4/8] Drivers: hv: vmbus: Remove unnecessary channel->lock critical sections (sc_list readers)
Date: Wed, 17 Jun 2020 18:46:38 +0200 [thread overview]
Message-ID: <20200617164642.37393-5-parri.andrea@gmail.com> (raw)
In-Reply-To: <20200617164642.37393-1-parri.andrea@gmail.com>
Additions/deletions to/from sc_list (as well as modifications of
target_cpu(s)) are protected by channel_mutex, which hv_synic_cleanup()
and vmbus_bus_suspend() own for the duration of the channel->lock
critical section in question.
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
---
drivers/hv/hv.c | 3 ---
drivers/hv/vmbus_drv.c | 3 ---
2 files changed, 6 deletions(-)
diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
index 188b42b07f07b..0c637111e7c70 100644
--- a/drivers/hv/hv.c
+++ b/drivers/hv/hv.c
@@ -245,7 +245,6 @@ int hv_synic_cleanup(unsigned int cpu)
{
struct vmbus_channel *channel, *sc;
bool channel_found = false;
- unsigned long flags;
/*
* Hyper-V does not provide a way to change the connect CPU once
@@ -267,14 +266,12 @@ int hv_synic_cleanup(unsigned int cpu)
channel_found = true;
break;
}
- spin_lock_irqsave(&channel->lock, flags);
list_for_each_entry(sc, &channel->sc_list, sc_list) {
if (sc->target_cpu == cpu) {
channel_found = true;
break;
}
}
- spin_unlock_irqrestore(&channel->lock, flags);
if (channel_found)
break;
}
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 452c14c656e2a..b5ae45eb8aef7 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -2330,7 +2330,6 @@ static int vmbus_acpi_add(struct acpi_device *device)
static int vmbus_bus_suspend(struct device *dev)
{
struct vmbus_channel *channel, *sc;
- unsigned long flags;
while (atomic_read(&vmbus_connection.offer_in_progress) != 0) {
/*
@@ -2388,12 +2387,10 @@ static int vmbus_bus_suspend(struct device *dev)
continue;
}
- spin_lock_irqsave(&channel->lock, flags);
list_for_each_entry(sc, &channel->sc_list, sc_list) {
pr_err("Sub-channel not deleted!\n");
WARN_ON_ONCE(1);
}
- spin_unlock_irqrestore(&channel->lock, flags);
atomic_inc(&vmbus_connection.nr_chan_fixup_on_resume);
}
--
2.25.1
next prev parent reply other threads:[~2020-06-17 16:48 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-17 16:46 [PATCH 0/8] Drivers: hv: vmbus: Miscellaneous cleanups Andrea Parri (Microsoft)
2020-06-17 16:46 ` [PATCH 1/8] Drivers: hv: vmbus: Remove the target_vp field from the vmbus_channel struct Andrea Parri (Microsoft)
2020-06-18 15:24 ` Michael Kelley
2020-06-17 16:46 ` [PATCH 2/8] Drivers: hv: vmbus: Remove the numa_node " Andrea Parri (Microsoft)
2020-06-18 15:26 ` Michael Kelley
2020-06-17 16:46 ` [PATCH 3/8] Drivers: hv: vmbus: Replace cpumask_test_cpu(, cpu_online_mask) with cpu_online() Andrea Parri (Microsoft)
2020-06-18 15:27 ` Michael Kelley
2020-06-17 16:46 ` Andrea Parri (Microsoft) [this message]
2020-06-18 15:29 ` [PATCH 4/8] Drivers: hv: vmbus: Remove unnecessary channel->lock critical sections (sc_list readers) Michael Kelley
2020-06-17 16:46 ` [PATCH 5/8] Drivers: hv: vmbus: Use channel_mutex in channel_vp_mapping_show() Andrea Parri (Microsoft)
2020-06-18 18:31 ` Michael Kelley
2020-06-17 16:46 ` [PATCH 6/8] Drivers: hv: vmbus: Remove unnecessary channel->lock critical sections (sc_list updaters) Andrea Parri (Microsoft)
2020-06-18 18:32 ` Michael Kelley
2020-06-17 16:46 ` [PATCH 7/8] scsi: storvsc: Introduce the per-storvsc_device spinlock Andrea Parri (Microsoft)
2020-06-18 18:34 ` Michael Kelley
2020-06-19 16:01 ` Wei Liu
2020-06-19 16:18 ` Andrea Parri
2020-06-20 2:58 ` Martin K. Petersen
2020-06-20 9:15 ` Wei Liu
2020-06-17 16:46 ` [PATCH 8/8] Drivers: hv: vmbus: Remove the lock field from the vmbus_channel struct Andrea Parri (Microsoft)
2020-06-18 18:35 ` Michael Kelley
2020-06-19 15:39 ` [PATCH 0/8] Drivers: hv: vmbus: Miscellaneous cleanups Wei Liu
2020-06-19 15:56 ` Wei Liu
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