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From: Juergen Gross <jgross@suse.com>
To: keir@xen.org, jbeulich@suse.com, andrew.cooper3@citrix.com,
	dario.faggioli@citrix.com, george.dunlap@eu.citrix.com,
	xen-devel@lists.xen.org
Cc: Juergen Gross <jgross@suse.com>
Subject: [PATCH 3/5] xen: use masking operation instead of test_bit for VGCF bits
Date: Fri,  2 Oct 2015 06:40:28 +0200	[thread overview]
Message-ID: <1443760830-29095-4-git-send-email-jgross@suse.com> (raw)
In-Reply-To: <1443760830-29095-1-git-send-email-jgross@suse.com>

Use a bit mask for testing of a set bit instead of test_bit in case no
atomic operation is needed, as this will lead to smaller and more
effective code.

Signed-off-by: Juergen Gross <jgross@suse.com>
---
 xen/arch/x86/domain.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c
index dc3bb08..4e96f6c 100644
--- a/xen/arch/x86/domain.c
+++ b/xen/arch/x86/domain.c
@@ -1352,7 +1352,7 @@ static void load_segments(struct vcpu *n)
                 domain_crash(n->domain);
             }
 
-            if ( test_bit(_VGCF_failsafe_disables_events, &n->arch.vgc_flags) )
+            if ( n->arch.vgc_flags & VGCF_failsafe_disables_events )
                 vcpu_info(n, evtchn_upcall_mask) = 1;
 
             regs->entry_vector |= TRAP_syscall;
@@ -1394,7 +1394,7 @@ static void load_segments(struct vcpu *n)
             domain_crash(n->domain);
         }
 
-        if ( test_bit(_VGCF_failsafe_disables_events, &n->arch.vgc_flags) )
+        if ( n->arch.vgc_flags & VGCF_failsafe_disables_events )
             vcpu_info(n, evtchn_upcall_mask) = 1;
 
         regs->entry_vector |= TRAP_syscall;
-- 
2.1.4

  parent reply	other threads:[~2015-10-02  4:40 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-10-02  4:40 [PATCH 0/5] use mask operations instead of test_bit() Juergen Gross
2015-10-02  4:40 ` [PATCH 1/5] xen: use masking operation instead of test_bit for RTDS bits Juergen Gross
2015-10-02 10:21   ` Dario Faggioli
2015-10-05 13:30   ` George Dunlap
2015-10-02  4:40 ` [PATCH 2/5] xen: use masking operation instead of test_bit for CSFLAG bits Juergen Gross
2015-10-02 10:45   ` Dario Faggioli
2015-10-05 13:30   ` George Dunlap
2015-10-02  4:40 ` Juergen Gross [this message]
2015-10-02  4:40 ` [PATCH 4/5] xen: use masking operation instead of test_bit for VPF bits Juergen Gross
2015-10-05 13:18   ` George Dunlap
2015-10-05 13:36     ` Jan Beulich
2015-10-05 13:45       ` George Dunlap
2015-10-05 14:05         ` Jan Beulich
2015-10-05 14:31           ` George Dunlap
2015-10-05 13:39     ` Juergen Gross
2015-10-05 13:24   ` George Dunlap
2015-10-05 13:40     ` Jan Beulich
2015-10-02  4:40 ` [PATCH 5/5] xen: use masking operation instead of test_bit for MCSF bits Juergen Gross
2015-10-02  9:03 ` [PATCH 0/5] use mask operations instead of test_bit() Dario Faggioli
2015-10-02  9:10   ` Juergen Gross
2015-10-02  9:33     ` Dario Faggioli
2015-10-02  9:44 ` Jan Beulich
2015-10-02  9:47 ` Andrew Cooper

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