linux-kernel - [PATCH 7/11] KVM: Remove redundant check in the kvm_get_dirty_log

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Message-Id: <20190104085405.40356-8-Tianyu.Lan@microsoft.com>
Date:   Fri,  4 Jan 2019 16:54:01 +0800
From:   lantianyu1986@...il.com
To:     unlisted-recipients:; (no To-header on input)
Cc:     Lan Tianyu <Tianyu.Lan@...rosoft.com>, christoffer.dall@....com,
        marc.zyngier@....com, linux@...linux.org.uk,
        catalin.marinas@....com, will.deacon@....com, jhogan@...nel.org,
        ralf@...ux-mips.org, paul.burton@...s.com, paulus@...abs.org,
        benh@...nel.crashing.org, mpe@...erman.id.au, pbonzini@...hat.com,
        rkrcmar@...hat.com, tglx@...utronix.de, mingo@...hat.com,
        bp@...en8.de, hpa@...or.com, x86@...nel.org,
        linux-arm-kernel@...ts.infradead.org, kvmarm@...ts.cs.columbia.edu,
        linux-kernel@...r.kernel.org, linux-mips@...r.kernel.org,
        kvm-ppc@...r.kernel.org, linuxppc-dev@...ts.ozlabs.org,
        kvm@...r.kernel.org, michael.h.kelley@...rosoft.com,
        kys@...rosoft.com, vkuznets@...hat.com
Subject: [PATCH 7/11] KVM: Remove redundant check in the kvm_get_dirty_log_protect()

From: Lan Tianyu <Tianyu.Lan@...rosoft.com>

The dirty bits have already been checked in the previous check of
"dirty_bitmap" and mask must be non-zero value at this point.

Signed-off-by: Lan Tianyu <Tianyu.Lan@...rosoft.com>
---
 virt/kvm/kvm_main.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index cf7cc0554094..e75dbb15fd09 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1206,11 +1206,9 @@ int kvm_get_dirty_log_protect(struct kvm *kvm,
 			mask = xchg(&dirty_bitmap[i], 0);
 			dirty_bitmap_buffer[i] = mask;
 
-			if (mask) {
-				offset = i * BITS_PER_LONG;
-				kvm_arch_mmu_enable_log_dirty_pt_masked(kvm, memslot,
-									offset, mask);
-			}
+			offset = i * BITS_PER_LONG;
+			kvm_arch_mmu_enable_log_dirty_pt_masked(kvm, memslot,
+								offset, mask);
 		}
 		spin_unlock(&kvm->mmu_lock);
 	}
-- 
2.14.4