From mboxrd@z Thu Jan 1 00:00:00 1970 From: Julien Thierry Subject: [PATCH kvmtool 09/16] brlock: Use rwlock instead of pause Date: Thu, 7 Mar 2019 08:36:10 +0000 Message-ID: <1551947777-13044-10-git-send-email-julien.thierry@arm.com> References: <1551947777-13044-1-git-send-email-julien.thierry@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: Andre.Przywara@arm.com, Sami.Mujawar@arm.com, will.deacon@arm.com, kvm@vger.kernel.org To: kvmarm@lists.cs.columbia.edu Return-path: In-Reply-To: <1551947777-13044-1-git-send-email-julien.thierry@arm.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu List-Id: kvm.vger.kernel.org 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 --- 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