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: [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) 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 _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
WARNING: multiple messages have this Message-ID (diff)
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 _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
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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