From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
To: agraf@suse.de, benh@kernel.crashing.org, paulus@samba.org
Cc: linuxppc-dev@lists.ozlabs.org, kvm@vger.kernel.org,
kvm-ppc@vger.kernel.org,
"Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Subject: [PATCH] KVM: PPC: Use schedule instead of cond_resched
Date: Tue, 10 Dec 2013 19:51:24 +0530 [thread overview]
Message-ID: <1386685284-3862-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> (raw)
From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
We already checked need_resched. So we can call schedule directly
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
---
NOTE: This patch also work around a regression upstream w.r.t PR KVM
BUG: soft lockup - CPU#0 stuck for 23s! [qemu-system-ppc:4394]
Modules linked in:
CPU: 0 PID: 4394 Comm: qemu-system-ppc Not tainted 3.13.0-rc3+ #98
task: c0000001d0788400 ti: c0000001dca00000 task.ti: c0000001dca00000
NIP: c00000000082dd80 LR: c000000000081ae0 CTR: c000000000062ba0
REGS: c0000001dca02f70 TRAP: 0901 Not tainted (3.13.0-rc3+)
MSR: 8000000000009032 <SF,EE,ME,IR,DR,RI> CR: 24822024 XER: 00000000
CFAR: c000000000081adc SOFTE: 1
GPR00: c000000000081ae0 c0000001dca031f0 c000000000d67ab0 0000000000000001
GPR04: 0000000071000002 0000000000000001 00000189a0d786b7 00000000018c0000
GPR08: 0000000000000001 0000000000000000 0000000000000000 c000000000da0000
GPR12: 0000000000000c00 c00000000fef0000
NIP [c00000000082dd80] ._cond_resched+0x0/0x40
LR [c000000000081ae0] .kvmppc_prepare_to_enter+0x2a0/0x2e0
Call Trace:
[c0000001dca031f0] [c000000000081ae0] .kvmppc_prepare_to_enter+0x2a0/0x2e0 (unreliable)
[c0000001dca03290] [c00000000008f2cc] .kvmppc_handle_exit_pr+0xec/0xa40
[c0000001dca03340] [c0000000000918c4] kvm_start_lightweight+0xac/0xbc
[c0000001dca03510] [c00000000008efe0] .kvmppc_vcpu_run_pr+0x130/0x2a0
[c0000001dca039e0] [c0000000000855bc] .kvmppc_vcpu_run+0x2c/0x40
[c0000001dca03a50] [c000000000082c94] .kvm_arch_vcpu_ioctl_run+0x54/0x1b0
[c0000001dca03ae0] [c00000000007d5f8] .kvm_vcpu_ioctl+0x478/0x740
[c0000001dca03ca0] [c000000000218864] .do_vfs_ioctl+0x4a4/0x760
[c0000001dca03d80] [c000000000218b78] .SyS_ioctl+0x58/0xb0
[c0000001dca03e30] [c000000000009e58] syscall_exit+0x0/0x98
Instruction dump:
e92d0260 e94911c0 812a0004 5529f07e 5529103e 912a0004 38210080 e8010010
ebc1fff0 ebe1fff8 7c0803a6 4e800020 <7c0802a6> 38600000 f8010010 f821ff91
arch/powerpc/kvm/powerpc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index e4d511c8b38b..6a49b23a3276 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -74,7 +74,7 @@ int kvmppc_prepare_to_enter(struct kvm_vcpu *vcpu)
while (true) {
if (need_resched()) {
local_irq_enable();
- cond_resched();
+ schedule();
local_irq_disable();
continue;
}
--
1.8.3.2
next reply other threads:[~2013-12-11 0:52 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-12-10 14:21 Aneesh Kumar K.V [this message]
2013-12-10 14:40 ` [PATCH] KVM: PPC: Use schedule instead of cond_resched Alexander Graf
2013-12-10 16:08 ` Aneesh Kumar K.V
2013-12-10 17:00 ` Alexander Graf
2013-12-10 20:52 ` Benjamin Herrenschmidt
2013-12-10 22:48 ` Peter Zijlstra
2013-12-10 22:59 ` Benjamin Herrenschmidt
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