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From: Julien Thierry <julien.thierry@arm.com>
To: kvmarm@lists.cs.columbia.edu
Cc: Andre.Przywara@arm.com, Sami.Mujawar@arm.com,
	will.deacon@arm.com, kvm@vger.kernel.org
Subject: [PATCH kvmtool 09/16] brlock: Use rwlock instead of pause
Date: Thu,  7 Mar 2019 08:36:10 +0000	[thread overview]
Message-ID: <1551947777-13044-10-git-send-email-julien.thierry@arm.com> (raw)
In-Reply-To: <1551947777-13044-1-git-send-email-julien.thierry@arm.com>

Pausing all vcpus when reconfiguring something at run time is a big
overhead. Use rwlock to allow vcpu not accessing ressources being
reconfigured to continue running.

Signed-off-by: Julien Thierry <julien.thierry@arm.com>
---
 include/kvm/brlock.h | 11 -----------
 include/kvm/kvm.h    |  2 --
 2 files changed, 13 deletions(-)

diff --git a/include/kvm/brlock.h b/include/kvm/brlock.h
index 1862210..7d81056 100644
--- a/include/kvm/brlock.h
+++ b/include/kvm/brlock.h
@@ -17,8 +17,6 @@
 #define barrier()		__asm__ __volatile__("": : :"memory")
 #endif
 
-#ifdef KVM_BRLOCK_DEBUG
-
 #include "kvm/rwsem.h"
 
 #define br_read_lock(kvm)	down_read(&(kvm)->brlock_sem);
@@ -27,13 +25,4 @@
 #define br_write_lock(kvm)	down_write(&(kvm)->brlock_sem);
 #define br_write_unlock(kvm)	up_write(&(kvm)->brlock_sem);
 
-#else
-
-#define br_read_lock(kvm)	barrier()
-#define br_read_unlock(kvm)	barrier()
-
-#define br_write_lock(kvm)	kvm__pause(kvm)
-#define br_write_unlock(kvm)	kvm__continue(kvm)
-#endif
-
 #endif
diff --git a/include/kvm/kvm.h b/include/kvm/kvm.h
index 7a73818..2f1679e 100644
--- a/include/kvm/kvm.h
+++ b/include/kvm/kvm.h
@@ -82,9 +82,7 @@ struct kvm {
 
 	int			vm_state;
 
-#ifdef KVM_BRLOCK_DEBUG
 	pthread_rwlock_t	brlock_sem;
-#endif
 };
 
 void kvm__set_dir(const char *fmt, ...);
-- 
1.9.1

  parent reply	other threads:[~2019-03-07  8:36 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-03-07  8:36 [PATCH kvmtool 00/16] Support PCI BAR configuration Julien Thierry
2019-03-07  8:36 ` [PATCH kvmtool 01/16] Makefile: Only compile vesa for archs that need it Julien Thierry
2019-04-04 13:43   ` Andre Przywara
2019-03-07  8:36 ` [PATCH kvmtool 02/16] brlock: Always pass argument to br_read_lock/unlock Julien Thierry
2019-04-04 13:43   ` Andre Przywara
2019-03-07  8:36 ` [PATCH kvmtool 03/16] brlock: fix build with KVM_BRLOCK_DEBUG Julien Thierry
2019-04-04 13:43   ` Andre Przywara
2019-03-07  8:36 ` [PATCH kvmtool 04/16] pci: Fix BAR resource sizing arbitration Julien Thierry
2019-04-04 13:44   ` Andre Przywara
2019-03-07  8:36 ` [PATCH kvmtool 05/16] ioport: pci: Move port allocations to PCI devices Julien Thierry
2019-04-04 13:45   ` Andre Przywara
2019-04-30  9:50     ` Julien Thierry
2019-03-07  8:36 ` [PATCH kvmtool 06/16] pci: Fix ioport allocation size Julien Thierry
2019-04-04 13:46   ` Andre Przywara
2019-03-07  8:36 ` [PATCH kvmtool 07/16] arm/pci: Fix PCI IO region Julien Thierry
2019-03-07  8:36 ` [PATCH kvmtool 08/16] arm/pci: Do not use first PCI IO space bytes for devices Julien Thierry
2019-04-05 15:31   ` Andre Przywara
2019-06-14  8:32     ` Julien Thierry
2019-03-07  8:36 ` Julien Thierry [this message]
2019-03-07  8:36 ` [PATCH kvmtool 10/16] ref_cnt: Add simple ref counting API Julien Thierry
2019-03-07  8:36 ` [PATCH kvmtool 11/16] mmio: Allow mmio callbacks to be called without locking Julien Thierry
2019-03-07  8:36 ` [PATCH kvmtool 12/16] ioport: Allow ioport " Julien Thierry
2019-03-07  8:36 ` [PATCH kvmtool 13/16] vfio: Add support for BAR configuration Julien Thierry
2019-03-07  8:36 ` [PATCH kvmtool 14/16] virtio/pci: Make memory and IO BARs independent Julien Thierry
2019-03-07  8:36 ` [PATCH kvmtool 15/16] virtio/pci: update virtio mapping when PCI BARs are reconfigured Julien Thierry
2019-03-07  8:36 ` [PATCH kvmtool 16/16] arm/fdt: Remove PCI probe only property Julien Thierry
2019-04-26 14:09 ` [PATCH kvmtool 00/16] Support PCI BAR configuration Will Deacon

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