From: Juergen Gross <jgross@suse.com>
To: xen-devel@lists.xenproject.org
Cc: "Juergen Gross" <jgross@suse.com>,
"Stefano Stabellini" <sstabellini@kernel.org>,
"Wei Liu" <wei.liu2@citrix.com>,
"Konrad Rzeszutek Wilk" <konrad.wilk@oracle.com>,
"George Dunlap" <George.Dunlap@eu.citrix.com>,
"Andrew Cooper" <andrew.cooper3@citrix.com>,
"Ian Jackson" <ian.jackson@eu.citrix.com>,
"Tim Deegan" <tim@xen.org>, "Julien Grall" <julien.grall@arm.com>,
"Jan Beulich" <jbeulich@suse.com>,
"Roger Pau Monné" <roger.pau@citrix.com>
Subject: [Xen-devel] [PATCH 1/3] xen: drop in_atomic()
Date: Wed, 22 May 2019 11:45:47 +0200 [thread overview]
Message-ID: <20190522094549.28397-2-jgross@suse.com> (raw)
Message-ID: <20190522094547.a6l4S-w7tBB5faAiQ-Ygc-qsrcJAxREnuaIIrrTw_Ik@z> (raw)
In-Reply-To: <20190522094549.28397-1-jgross@suse.com>
Currently there is only one user of in_atomic(), and that is in an
#ifdef 0 section. This has been so since Xen 4.1, so chances are
rather slim we suddenly want to enable it again.
Dropping in_atomic() will remove the last user of preempt_count()
in non-debug builds enabling further optimizations.
Signed-off-by: Juergen Gross <jgross@suse.com>
---
xen/arch/x86/hvm/hvm.c | 16 ----------------
xen/common/preempt.c | 5 -----
xen/include/xen/preempt.h | 2 --
3 files changed, 23 deletions(-)
diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 8993c2aa57..7b36765b97 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -3185,22 +3185,6 @@ static enum hvm_translation_result __hvm_copy(
ASSERT(is_hvm_vcpu(v));
- /*
- * XXX Disable for 4.1.0: PV-on-HVM drivers will do grant-table ops
- * such as query_size. Grant-table code currently does copy_to/from_guest
- * accesses under the big per-domain lock, which this test would disallow.
- * The test is not needed until we implement sleeping-on-waitqueue when
- * we access a paged-out frame, and that's post 4.1.0 now.
- */
-#if 0
- /*
- * If the required guest memory is paged out, this function may sleep.
- * Hence we bail immediately if called from atomic context.
- */
- if ( in_atomic() )
- return HVMTRANS_unhandleable;
-#endif
-
while ( todo > 0 )
{
enum hvm_translation_result res;
diff --git a/xen/common/preempt.c b/xen/common/preempt.c
index 3b4178fd44..20913e20d3 100644
--- a/xen/common/preempt.c
+++ b/xen/common/preempt.c
@@ -25,11 +25,6 @@
DEFINE_PER_CPU(unsigned int, __preempt_count);
-bool_t in_atomic(void)
-{
- return preempt_count() || in_irq() || !local_irq_is_enabled();
-}
-
#ifndef NDEBUG
void ASSERT_NOT_IN_ATOMIC(void)
{
diff --git a/xen/include/xen/preempt.h b/xen/include/xen/preempt.h
index bef83135a1..f715ca09bc 100644
--- a/xen/include/xen/preempt.h
+++ b/xen/include/xen/preempt.h
@@ -26,8 +26,6 @@ DECLARE_PER_CPU(unsigned int, __preempt_count);
preempt_count()--; \
} while (0)
-bool_t in_atomic(void);
-
#ifndef NDEBUG
void ASSERT_NOT_IN_ATOMIC(void);
#else
--
2.16.4
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next prev parent reply other threads:[~2019-05-22 9:46 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-22 9:45 [PATCH 0/3] tune preempt_[dis|en]able() Juergen Gross
2019-05-22 9:45 ` [Xen-devel] " Juergen Gross
2019-05-22 9:45 ` Juergen Gross [this message]
2019-05-22 9:45 ` [Xen-devel] [PATCH 1/3] xen: drop in_atomic() Juergen Gross
2019-05-22 9:58 ` Andrew Cooper
2019-05-22 9:58 ` [Xen-devel] " Andrew Cooper
2019-05-22 10:10 ` Jan Beulich
2019-05-22 10:10 ` [Xen-devel] " Jan Beulich
2019-05-24 5:41 ` Juergen Gross
2019-05-24 5:41 ` [Xen-devel] " Juergen Gross
2019-05-24 6:38 ` Jan Beulich
2019-05-24 6:38 ` [Xen-devel] " Jan Beulich
2019-05-24 8:34 ` Juergen Gross
2019-05-24 8:34 ` [Xen-devel] " Juergen Gross
2019-05-24 8:39 ` Jan Beulich
2019-05-24 8:39 ` [Xen-devel] " Jan Beulich
2019-05-24 12:30 ` Andrew Cooper
2019-05-24 12:30 ` [Xen-devel] " Andrew Cooper
2019-05-24 12:35 ` Jan Beulich
2019-05-24 12:35 ` [Xen-devel] " Jan Beulich
[not found] ` <5CE52014020000780023147E@suse.com>
2019-05-22 10:19 ` Juergen Gross
2019-05-22 10:19 ` [Xen-devel] " Juergen Gross
2019-05-22 12:34 ` Jan Beulich
2019-05-22 12:34 ` [Xen-devel] " Jan Beulich
2019-05-22 9:45 ` [PATCH 2/3] xen: drop preempt_count() for non-debug builds Juergen Gross
2019-05-22 9:45 ` [Xen-devel] " Juergen Gross
2019-05-22 10:00 ` Andrew Cooper
2019-05-22 10:00 ` [Xen-devel] " Andrew Cooper
2019-05-22 10:17 ` Juergen Gross
2019-05-22 10:17 ` [Xen-devel] " Juergen Gross
2019-05-22 10:18 ` Jan Beulich
2019-05-22 10:18 ` [Xen-devel] " Jan Beulich
2019-05-22 10:39 ` Andrew Cooper
2019-05-22 10:39 ` [Xen-devel] " Andrew Cooper
2019-05-22 10:12 ` Jan Beulich
2019-05-22 10:12 ` [Xen-devel] " Jan Beulich
[not found] ` <5CE5207A0200007800231481@suse.com>
2019-05-22 10:17 ` Juergen Gross
2019-05-22 10:17 ` [Xen-devel] " Juergen Gross
2019-05-22 9:45 ` [PATCH 3/3] xen: build common/preempt.c only with CONFIG_DEBUG Juergen Gross
2019-05-22 9:45 ` [Xen-devel] " Juergen Gross
2019-05-22 13:01 [PATCH 1/3] xen: drop in_atomic() Juergen Gross
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