* [PATCH for 4.16] membarrier-sync-core: Document architecture support
@ 2018-02-09 20:30 Mathieu Desnoyers
2018-02-10 11:47 ` Ingo Molnar
` (2 more replies)
0 siblings, 3 replies; 6+ messages in thread
From: Mathieu Desnoyers @ 2018-02-09 20:30 UTC (permalink / raw)
To: Ingo Molnar
Cc: linux-kernel, Mathieu Desnoyers, Thomas Gleixner,
Peter Zijlstra (Intel), Andrea Parri, Andrew Hunter,
Andy Lutomirski, Avi Kivity, Benjamin Herrenschmidt, Boqun Feng,
Dave Watson, David Sehr, Greg Hackmann, H. Peter Anvin,
Linus Torvalds, Maged Michael, Michael Ellerman, Paul E. McKenney,
Paul Mackerras, Russell King, Will Deacon, linux-api, linux-arch
Ensure we gather architecture requirements about each architecture
supporting the "sync_core" membarrier command in a single file under
Documentation/features.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrea Parri <parri.andrea@gmail.com>
Cc: Andrew Hunter <ahh@google.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Avi Kivity <avi@scylladb.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Dave Watson <davejwatson@fb.com>
Cc: David Sehr <sehr@google.com>
Cc: Greg Hackmann <ghackmann@google.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Maged Michael <maged.michael@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-api@vger.kernel.org
Cc: linux-arch@vger.kernel.org
---
.../sched/membarrier-sync-core/arch-support.txt | 62 ++++++++++++++++++++++
1 file changed, 62 insertions(+)
create mode 100644 Documentation/features/sched/membarrier-sync-core/arch-support.txt
diff --git a/Documentation/features/sched/membarrier-sync-core/arch-support.txt b/Documentation/features/sched/membarrier-sync-core/arch-support.txt
new file mode 100644
index 0000000..2c815a7
--- /dev/null
+++ b/Documentation/features/sched/membarrier-sync-core/arch-support.txt
@@ -0,0 +1,62 @@
+#
+# Feature name: membarrier-sync-core
+# Kconfig: ARCH_HAS_MEMBARRIER_SYNC_CORE
+# description: arch supports core serializing membarrier
+#
+# Architecture requirements
+#
+# * arm64
+#
+# Rely on eret context synchronization when returning from IPI handler, and
+# when returning to user-space.
+#
+# * x86
+#
+# x86-32 uses IRET as return from interrupt, which takes care of the IPI.
+# However, it uses both IRET and SYSEXIT to go back to user-space. The IRET
+# instruction is core serializing, but not SYSEXIT.
+#
+# x86-64 uses IRET as return from interrupt, which takes care of the IPI.
+# However, it can return to user-space through either SYSRETL (compat code),
+# SYSRETQ, or IRET.
+#
+# Given that neither SYSRET{L,Q}, nor SYSEXIT, are core serializing, we rely
+# instead on write_cr3() performed by switch_mm() to provide core serialization
+# after changing the current mm, and deal with the special case of kthread ->
+# uthread (temporarily keeping current mm into active_mm) by issuing a
+# sync_core_before_usermode() in that specific case.
+#
+ -----------------------
+ | arch |status|
+ -----------------------
+ | alpha: | TODO |
+ | arc: | TODO |
+ | arm: | TODO |
+ | arm64: | ok |
+ | blackfin: | TODO |
+ | c6x: | TODO |
+ | cris: | TODO |
+ | frv: | TODO |
+ | h8300: | TODO |
+ | hexagon: | TODO |
+ | ia64: | TODO |
+ | m32r: | TODO |
+ | m68k: | TODO |
+ | metag: | TODO |
+ | microblaze: | TODO |
+ | mips: | TODO |
+ | mn10300: | TODO |
+ | nios2: | TODO |
+ | openrisc: | TODO |
+ | parisc: | TODO |
+ | powerpc: | TODO |
+ | s390: | TODO |
+ | score: | TODO |
+ | sh: | TODO |
+ | sparc: | TODO |
+ | tile: | TODO |
+ | um: | TODO |
+ | unicore32: | TODO |
+ | x86: | ok |
+ | xtensa: | TODO |
+ -----------------------
--
1.9.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH for 4.16] membarrier-sync-core: Document architecture support
2018-02-09 20:30 [PATCH for 4.16] membarrier-sync-core: Document architecture support Mathieu Desnoyers
@ 2018-02-10 11:47 ` Ingo Molnar
2018-02-10 17:00 ` [PATCH for 4.16] Documentation: Allow comments in arch features files Mathieu Desnoyers
2018-02-11 12:08 ` [tip:sched/urgent] membarrier-sync-core: Document architecture support tip-bot for Mathieu Desnoyers
2018-02-11 12:13 ` [tip:core/core] Documentation/features, membarriers: Document membarrier-sync-core " tip-bot for Mathieu Desnoyers
2 siblings, 1 reply; 6+ messages in thread
From: Ingo Molnar @ 2018-02-10 11:47 UTC (permalink / raw)
To: Mathieu Desnoyers
Cc: linux-kernel, Thomas Gleixner, Peter Zijlstra (Intel),
Andrea Parri, Andrew Hunter, Andy Lutomirski, Avi Kivity,
Benjamin Herrenschmidt, Boqun Feng, Dave Watson, David Sehr,
Greg Hackmann, H. Peter Anvin, Linus Torvalds, Maged Michael,
Michael Ellerman, Paul E. McKenney, Paul Mackerras, Russell King,
Will Deacon, linux-api, linux-arch
* Mathieu Desnoyers <mathieu.desnoyers@efficios.com> wrote:
> Ensure we gather architecture requirements about each architecture
> supporting the "sync_core" membarrier command in a single file under
> Documentation/features.
>
> Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
> Cc: Ingo Molnar <mingo@kernel.org>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
> Cc: Andrea Parri <parri.andrea@gmail.com>
> Cc: Andrew Hunter <ahh@google.com>
> Cc: Andy Lutomirski <luto@kernel.org>
> Cc: Avi Kivity <avi@scylladb.com>
> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Cc: Boqun Feng <boqun.feng@gmail.com>
> Cc: Dave Watson <davejwatson@fb.com>
> Cc: David Sehr <sehr@google.com>
> Cc: Greg Hackmann <ghackmann@google.com>
> Cc: H. Peter Anvin <hpa@zytor.com>
> Cc: Linus Torvalds <torvalds@linux-foundation.org>
> Cc: Maged Michael <maged.michael@gmail.com>
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
> Cc: Paul Mackerras <paulus@samba.org>
> Cc: Russell King <linux@armlinux.org.uk>
> Cc: Will Deacon <will.deacon@arm.com>
> Cc: linux-api@vger.kernel.org
> Cc: linux-arch@vger.kernel.org
> ---
> .../sched/membarrier-sync-core/arch-support.txt | 62 ++++++++++++++++++++++
> 1 file changed, 62 insertions(+)
> create mode 100644 Documentation/features/sched/membarrier-sync-core/arch-support.txt
>
> diff --git a/Documentation/features/sched/membarrier-sync-core/arch-support.txt b/Documentation/features/sched/membarrier-sync-core/arch-support.txt
> new file mode 100644
> index 0000000..2c815a7
> --- /dev/null
> +++ b/Documentation/features/sched/membarrier-sync-core/arch-support.txt
> @@ -0,0 +1,62 @@
> +#
> +# Feature name: membarrier-sync-core
> +# Kconfig: ARCH_HAS_MEMBARRIER_SYNC_CORE
> +# description: arch supports core serializing membarrier
This breaks the output of the Documentation/features/list-arch.sh script.
Thanks,
Ingo
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH for 4.16] Documentation: Allow comments in arch features files
2018-02-10 11:47 ` Ingo Molnar
@ 2018-02-10 17:00 ` Mathieu Desnoyers
2018-02-11 12:12 ` [tip:core/core] Documentation/features: " tip-bot for Mathieu Desnoyers
0 siblings, 1 reply; 6+ messages in thread
From: Mathieu Desnoyers @ 2018-02-10 17:00 UTC (permalink / raw)
To: Ingo Molnar
Cc: linux-kernel, Mathieu Desnoyers, Thomas Gleixner,
Peter Zijlstra (Intel), Andrea Parri, Andrew Hunter,
Andy Lutomirski, Avi Kivity, Benjamin Herrenschmidt, Boqun Feng,
Dave Watson, David Sehr, Greg Hackmann, H. Peter Anvin,
Linus Torvalds, Maged Michael, Michael Ellerman, Paul E. McKenney,
Paul Mackerras, Russell King, Will Deacon, linux-api, linux-arch
The list-arch.sh script considers lines beginning with "#" as match for
the feature table.
Given that those tables are never in lines beginning with "#",
add a reverse grep on "^#" when matching the "ok/TODO" state of
the architecture.
This allows adding comments within the feature files, for instance
describing the architecture requirements for the feature in each
architecture.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrea Parri <parri.andrea@gmail.com>
Cc: Andrew Hunter <ahh@google.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Avi Kivity <avi@scylladb.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Dave Watson <davejwatson@fb.com>
Cc: David Sehr <sehr@google.com>
Cc: Greg Hackmann <ghackmann@google.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Maged Michael <maged.michael@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-api@vger.kernel.org
Cc: linux-arch@vger.kernel.org
---
Documentation/features/list-arch.sh | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/Documentation/features/list-arch.sh b/Documentation/features/list-arch.sh
index c16b5b5..1ec47c3 100755
--- a/Documentation/features/list-arch.sh
+++ b/Documentation/features/list-arch.sh
@@ -17,7 +17,7 @@ for F in */*/arch-support.txt; do
N=$(grep -h "^# Feature name:" $F | cut -c25-)
C=$(grep -h "^# Kconfig:" $F | cut -c25-)
D=$(grep -h "^# description:" $F | cut -c25-)
- S=$(grep -hw $ARCH $F | cut -d\| -f3)
+ S=$(grep -hv "^#" $F | grep -w $ARCH | cut -d\| -f3)
printf "%10s/%-22s:%s| %35s # %s\n" "$SUBSYS" "$N" "$S" "$C" "$D"
done
--
1.9.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [tip:sched/urgent] membarrier-sync-core: Document architecture support
2018-02-09 20:30 [PATCH for 4.16] membarrier-sync-core: Document architecture support Mathieu Desnoyers
2018-02-10 11:47 ` Ingo Molnar
@ 2018-02-11 12:08 ` tip-bot for Mathieu Desnoyers
2018-02-11 12:13 ` [tip:core/core] Documentation/features, membarriers: Document membarrier-sync-core " tip-bot for Mathieu Desnoyers
2 siblings, 0 replies; 6+ messages in thread
From: tip-bot for Mathieu Desnoyers @ 2018-02-11 12:08 UTC (permalink / raw)
To: linux-tip-commits
Cc: parri.andrea, peterz, mingo, mathieu.desnoyers, benh, tglx,
davejwatson, sehr, ghackmann, linux-kernel, boqun.feng, ahh,
paulmck, maged.michael, avi, torvalds, linux, hpa, luto, paulus,
will.deacon, mpe
Commit-ID: 6a546c7e69ff0b69581377cc70d7e8a601b98fce
Gitweb: https://git.kernel.org/tip/6a546c7e69ff0b69581377cc70d7e8a601b98fce
Author: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
AuthorDate: Fri, 9 Feb 2018 15:30:56 -0500
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Sat, 10 Feb 2018 12:45:10 +0100
membarrier-sync-core: Document architecture support
Ensure we gather architecture requirements about each architecture
supporting the "sync_core" membarrier command in a single file under
Documentation/features.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrea Parri <parri.andrea@gmail.com>
Cc: Andrew Hunter <ahh@google.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Avi Kivity <avi@scylladb.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Dave Watson <davejwatson@fb.com>
Cc: David Sehr <sehr@google.com>
Cc: Greg Hackmann <ghackmann@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Maged Michael <maged.michael@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-api@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Link: http://lkml.kernel.org/r/1518208256-22034-1-git-send-email-mathieu.desnoyers@efficios.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
.../sched/membarrier-sync-core/arch-support.txt | 62 ++++++++++++++++++++++
1 file changed, 62 insertions(+)
diff --git a/Documentation/features/sched/membarrier-sync-core/arch-support.txt b/Documentation/features/sched/membarrier-sync-core/arch-support.txt
new file mode 100644
index 0000000..2c815a7
--- /dev/null
+++ b/Documentation/features/sched/membarrier-sync-core/arch-support.txt
@@ -0,0 +1,62 @@
+#
+# Feature name: membarrier-sync-core
+# Kconfig: ARCH_HAS_MEMBARRIER_SYNC_CORE
+# description: arch supports core serializing membarrier
+#
+# Architecture requirements
+#
+# * arm64
+#
+# Rely on eret context synchronization when returning from IPI handler, and
+# when returning to user-space.
+#
+# * x86
+#
+# x86-32 uses IRET as return from interrupt, which takes care of the IPI.
+# However, it uses both IRET and SYSEXIT to go back to user-space. The IRET
+# instruction is core serializing, but not SYSEXIT.
+#
+# x86-64 uses IRET as return from interrupt, which takes care of the IPI.
+# However, it can return to user-space through either SYSRETL (compat code),
+# SYSRETQ, or IRET.
+#
+# Given that neither SYSRET{L,Q}, nor SYSEXIT, are core serializing, we rely
+# instead on write_cr3() performed by switch_mm() to provide core serialization
+# after changing the current mm, and deal with the special case of kthread ->
+# uthread (temporarily keeping current mm into active_mm) by issuing a
+# sync_core_before_usermode() in that specific case.
+#
+ -----------------------
+ | arch |status|
+ -----------------------
+ | alpha: | TODO |
+ | arc: | TODO |
+ | arm: | TODO |
+ | arm64: | ok |
+ | blackfin: | TODO |
+ | c6x: | TODO |
+ | cris: | TODO |
+ | frv: | TODO |
+ | h8300: | TODO |
+ | hexagon: | TODO |
+ | ia64: | TODO |
+ | m32r: | TODO |
+ | m68k: | TODO |
+ | metag: | TODO |
+ | microblaze: | TODO |
+ | mips: | TODO |
+ | mn10300: | TODO |
+ | nios2: | TODO |
+ | openrisc: | TODO |
+ | parisc: | TODO |
+ | powerpc: | TODO |
+ | s390: | TODO |
+ | score: | TODO |
+ | sh: | TODO |
+ | sparc: | TODO |
+ | tile: | TODO |
+ | um: | TODO |
+ | unicore32: | TODO |
+ | x86: | ok |
+ | xtensa: | TODO |
+ -----------------------
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [tip:core/core] Documentation/features: Allow comments in arch features files
2018-02-10 17:00 ` [PATCH for 4.16] Documentation: Allow comments in arch features files Mathieu Desnoyers
@ 2018-02-11 12:12 ` tip-bot for Mathieu Desnoyers
0 siblings, 0 replies; 6+ messages in thread
From: tip-bot for Mathieu Desnoyers @ 2018-02-11 12:12 UTC (permalink / raw)
To: linux-tip-commits
Cc: mingo, linux-kernel, mathieu.desnoyers, torvalds, corbet, hpa,
peterz, tglx
Commit-ID: 26be459c9c4431984ad4b576f975ce6d3184d71d
Gitweb: https://git.kernel.org/tip/26be459c9c4431984ad4b576f975ce6d3184d71d
Author: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
AuthorDate: Sat, 10 Feb 2018 12:00:58 -0500
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Sun, 11 Feb 2018 12:18:50 +0100
Documentation/features: Allow comments in arch features files
The list-arch.sh script considers lines beginning with "#" as match for
the feature table.
Given that those tables are never in lines beginning with "#",
add a reverse grep on "^#" when matching the "ok/TODO" state of
the architecture.
This allows adding comments within the feature files, for instance
describing the architecture requirements for the feature in each
architecture.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-doc@vger.kernel.org
Link: http://lkml.kernel.org/r/1518282058-24226-1-git-send-email-mathieu.desnoyers@efficios.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
Documentation/features/list-arch.sh | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/Documentation/features/list-arch.sh b/Documentation/features/list-arch.sh
index c16b5b5..1ec47c3 100755
--- a/Documentation/features/list-arch.sh
+++ b/Documentation/features/list-arch.sh
@@ -17,7 +17,7 @@ for F in */*/arch-support.txt; do
N=$(grep -h "^# Feature name:" $F | cut -c25-)
C=$(grep -h "^# Kconfig:" $F | cut -c25-)
D=$(grep -h "^# description:" $F | cut -c25-)
- S=$(grep -hw $ARCH $F | cut -d\| -f3)
+ S=$(grep -hv "^#" $F | grep -w $ARCH | cut -d\| -f3)
printf "%10s/%-22s:%s| %35s # %s\n" "$SUBSYS" "$N" "$S" "$C" "$D"
done
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [tip:core/core] Documentation/features, membarriers: Document membarrier-sync-core architecture support
2018-02-09 20:30 [PATCH for 4.16] membarrier-sync-core: Document architecture support Mathieu Desnoyers
2018-02-10 11:47 ` Ingo Molnar
2018-02-11 12:08 ` [tip:sched/urgent] membarrier-sync-core: Document architecture support tip-bot for Mathieu Desnoyers
@ 2018-02-11 12:13 ` tip-bot for Mathieu Desnoyers
2 siblings, 0 replies; 6+ messages in thread
From: tip-bot for Mathieu Desnoyers @ 2018-02-11 12:13 UTC (permalink / raw)
To: linux-tip-commits
Cc: peterz, corbet, mathieu.desnoyers, boqun.feng, paulmck, benh,
mingo, ahh, sehr, luto, hpa, davejwatson, ghackmann, linux-kernel,
maged.michael, avi, parri.andrea, torvalds, paulus, mpe,
will.deacon, linux, tglx
Commit-ID: ac65ddad4a23d46529f921fdf8f7b7b6d14a15d8
Gitweb: https://git.kernel.org/tip/ac65ddad4a23d46529f921fdf8f7b7b6d14a15d8
Author: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
AuthorDate: Fri, 9 Feb 2018 15:30:56 -0500
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Sun, 11 Feb 2018 12:19:03 +0100
Documentation/features, membarriers: Document membarrier-sync-core architecture support
Ensure we gather architecture requirements about each architecture
supporting the "sync_core" membarrier command in a single file under
Documentation/features.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrea Parri <parri.andrea@gmail.com>
Cc: Andrew Hunter <ahh@google.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Avi Kivity <avi@scylladb.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Dave Watson <davejwatson@fb.com>
Cc: David Sehr <sehr@google.com>
Cc: Greg Hackmann <ghackmann@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Maged Michael <maged.michael@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-api@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Link: http://lkml.kernel.org/r/1518208256-22034-1-git-send-email-mathieu.desnoyers@efficios.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
.../sched/membarrier-sync-core/arch-support.txt | 62 ++++++++++++++++++++++
1 file changed, 62 insertions(+)
diff --git a/Documentation/features/sched/membarrier-sync-core/arch-support.txt b/Documentation/features/sched/membarrier-sync-core/arch-support.txt
new file mode 100644
index 0000000..2c815a7
--- /dev/null
+++ b/Documentation/features/sched/membarrier-sync-core/arch-support.txt
@@ -0,0 +1,62 @@
+#
+# Feature name: membarrier-sync-core
+# Kconfig: ARCH_HAS_MEMBARRIER_SYNC_CORE
+# description: arch supports core serializing membarrier
+#
+# Architecture requirements
+#
+# * arm64
+#
+# Rely on eret context synchronization when returning from IPI handler, and
+# when returning to user-space.
+#
+# * x86
+#
+# x86-32 uses IRET as return from interrupt, which takes care of the IPI.
+# However, it uses both IRET and SYSEXIT to go back to user-space. The IRET
+# instruction is core serializing, but not SYSEXIT.
+#
+# x86-64 uses IRET as return from interrupt, which takes care of the IPI.
+# However, it can return to user-space through either SYSRETL (compat code),
+# SYSRETQ, or IRET.
+#
+# Given that neither SYSRET{L,Q}, nor SYSEXIT, are core serializing, we rely
+# instead on write_cr3() performed by switch_mm() to provide core serialization
+# after changing the current mm, and deal with the special case of kthread ->
+# uthread (temporarily keeping current mm into active_mm) by issuing a
+# sync_core_before_usermode() in that specific case.
+#
+ -----------------------
+ | arch |status|
+ -----------------------
+ | alpha: | TODO |
+ | arc: | TODO |
+ | arm: | TODO |
+ | arm64: | ok |
+ | blackfin: | TODO |
+ | c6x: | TODO |
+ | cris: | TODO |
+ | frv: | TODO |
+ | h8300: | TODO |
+ | hexagon: | TODO |
+ | ia64: | TODO |
+ | m32r: | TODO |
+ | m68k: | TODO |
+ | metag: | TODO |
+ | microblaze: | TODO |
+ | mips: | TODO |
+ | mn10300: | TODO |
+ | nios2: | TODO |
+ | openrisc: | TODO |
+ | parisc: | TODO |
+ | powerpc: | TODO |
+ | s390: | TODO |
+ | score: | TODO |
+ | sh: | TODO |
+ | sparc: | TODO |
+ | tile: | TODO |
+ | um: | TODO |
+ | unicore32: | TODO |
+ | x86: | ok |
+ | xtensa: | TODO |
+ -----------------------
^ permalink raw reply related [flat|nested] 6+ messages in thread
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2018-02-09 20:30 [PATCH for 4.16] membarrier-sync-core: Document architecture support Mathieu Desnoyers
2018-02-10 11:47 ` Ingo Molnar
2018-02-10 17:00 ` [PATCH for 4.16] Documentation: Allow comments in arch features files Mathieu Desnoyers
2018-02-11 12:12 ` [tip:core/core] Documentation/features: " tip-bot for Mathieu Desnoyers
2018-02-11 12:08 ` [tip:sched/urgent] membarrier-sync-core: Document architecture support tip-bot for Mathieu Desnoyers
2018-02-11 12:13 ` [tip:core/core] Documentation/features, membarriers: Document membarrier-sync-core " tip-bot for Mathieu Desnoyers
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