From patchwork Fri Jan 21 20:48:20 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [16/18] kvm: Do not use qemu_fair_mutex Date: Fri, 21 Jan 2011 10:48:20 -0000 From: Jan Kiszka X-Patchwork-Id: 79939 Message-Id: To: Avi Kivity , Marcelo Tosatti Cc: qemu-devel@nongnu.org, kvm@vger.kernel.org From: Jan Kiszka The imbalance in the hold time of qemu_global_mutex only exists in TCG mode. In contrast to TCG VCPUs, KVM drops the global lock during guest execution. We already avoid touching the fairness lock from the IO-thread in KVM mode, so also stop using it from the VCPU threads. Signed-off-by: Jan Kiszka --- cpus.c | 2 -- 1 files changed, 0 insertions(+), 2 deletions(-) diff --git a/cpus.c b/cpus.c index 0309189..4c9928e 100644 --- a/cpus.c +++ b/cpus.c @@ -735,9 +735,7 @@ static sigset_t block_io_signals(void) void qemu_mutex_lock_iothread(void) { if (kvm_enabled()) { - qemu_mutex_lock(&qemu_fair_mutex); qemu_mutex_lock(&qemu_global_mutex); - qemu_mutex_unlock(&qemu_fair_mutex); } else { qemu_mutex_lock(&qemu_fair_mutex); if (qemu_mutex_trylock(&qemu_global_mutex)) {