* [PATCH powerpc] cpuidle: fix per cpu accessing of cpuidle_devices
From: Li Zhong @ 2014-01-26 5:09 UTC (permalink / raw)
To: PowerPC email list, linux-pm
Cc: deepthi, rafael.j.wysocki, b.zolnierkie, daniel.lezcano,
kyungmin.park, Paul Mackerras
The patch tries to fix following bad address accessing, seems caused by
a typo in commit 7f74dc0f. cpuidle_devices is defined statically, so
per_cpu should be used to access it.
[ 204.774193] Unable to handle kernel paging request for data at address 0x00a7d000
[ 204.774215] Faulting instruction address: 0xc0000000006ee92c
[ 204.774225] Oops: Kernel access of bad area, sig: 11 [#1]
[ 204.774230] PREEMPT SMP NR_CPUS=16 DEBUG_PAGEALLOC NUMA pSeries
[ 204.774244] Modules linked in: binfmt_misc
[ 204.774254] CPU: 8 PID: 3590 Comm: bash Not tainted 3.13.0-08526-gb2e448e-dirty #2
[ 204.774262] task: c0000001faf40000 ti: c0000001fa904000 task.ti: c0000001fa904000
[ 204.774268] NIP: c0000000006ee92c LR: c0000000006ee920 CTR: c000000000064e94
[ 204.774275] REGS: c0000001fa907240 TRAP: 0300 Not tainted (3.13.0-08526-gb2e448e-dirty)
[ 204.774281] MSR: 8000000000009032 <SF,EE,ME,IR,DR,RI> CR: 22242424 XER: 20000000
[ 204.774303] CFAR: 0000000000009088 DAR: 0000000000a7d000 DSISR: 40000000 SOFTE: 1
GPR00: c0000000006ee920 c0000001fa9074c0 c000000000d764a8 c000000000c5d4c0
GPR04: 0000000000000010 0000000000000010 0000000000000000 0000000000000000
GPR08: ffffffffffffffff c0000000016564a8 ffffffffffffffff 0000000000000000
GPR12: 0000000000000002 c00000000f33e800 000000001012b3dc 0000000000000000
GPR16: 0000000000000000 0000000010129c58 0000000010129bf8 000000001012b948
GPR20: 0000000000000000 000000001012b3e4 000000001013ea90 0000000000000000
GPR24: c000000000c5d858 c0000000015f38e8 c000000000cb8b26 c000000000c664a8
GPR28: 0000000000000000 ffffffffffffffe5 0000000000a7d000 0000000000a7d000
[ 204.774407] NIP [c0000000006ee92c] .cpuidle_disable_device+0x30/0xc4
[ 204.774413] LR [c0000000006ee920] .cpuidle_disable_device+0x24/0xc4
[ 204.774419] Call Trace:
[ 204.774424] [c0000001fa9074c0] [c0000000006ee920] .cpuidle_disable_device+0x24/0xc4 (unreliable)
[ 204.774435] [c0000001fa907540] [c0000000000652a4] .pseries_cpuidle_add_cpu_notifier+0xb8/0xe0
[ 204.774445] [c0000001fa9075c0] [c000000000855548] .notifier_call_chain+0x150/0x1c0
[ 204.774455] [c0000001fa907670] [c0000000000b3564] .__raw_notifier_call_chain+0x40/0x50
[ 204.774463] [c0000001fa907710] [c000000000079c40] .__cpu_notify+0x50/0x9c
[ 204.774472] [c0000001fa9077a0] [c00000000018a054] ._cpu_down+0x1ec/0x388
[ 204.774479] [c0000001fa9078b0] [c00000000018a234] .cpu_down+0x44/0x64
[ 204.774488] [c0000001fa907940] [c0000000005627bc] .cpu_subsys_offline+0x24/0x3c
[ 204.774497] [c0000001fa9079c0] [c00000000055b2a4] .device_offline+0xc8/0x120
[ 204.774504] [c0000001fa907a50] [c00000000055d000] .online_store+0x74/0xb0
[ 204.774512] [c0000001fa907b00] [c000000000559924] .dev_attr_store+0x60/0x78
[ 204.774520] [c0000001fa907ba0] [c00000000028cc78] .sysfs_kf_write+0x7c/0x9c
[ 204.774528] [c0000001fa907c30] [c000000000291ae8] .kernfs_fop_write+0x108/0x174
[ 204.774537] [c0000001fa907cd0] [c0000000001f8308] .vfs_write+0x110/0x21c
[ 204.774545] [c0000001fa907d70] [c0000000001f854c] .SyS_write+0x70/0xbc
[ 204.774553] [c0000001fa907e30] [c000000000009d88] syscall_exit+0x0/0x7c
[ 204.774560] Instruction dump:
[ 204.774565] 7c0802a6 f8010010 fbe1fff8 f821ff81 7c7f1b78 60000000 60000000 7fe3fb78
[ 204.774582] 48000c89 60000000 2fbf0000 419e0084 <e81f0000> 780b17e1 41820078 2fa30000
[ 204.774601] ---[ end trace edf1df93cf81e28d ]---
Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com>
---
arch/powerpc/platforms/pseries/processor_idle.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/arch/powerpc/platforms/pseries/processor_idle.c b/arch/powerpc/platforms/pseries/processor_idle.c
index 94134a5..197cadc 100644
--- a/arch/powerpc/platforms/pseries/processor_idle.c
+++ b/arch/powerpc/platforms/pseries/processor_idle.c
@@ -190,7 +190,7 @@ static int pseries_cpuidle_add_cpu_notifier(struct notifier_block *n,
{
int hotcpu = (unsigned long)hcpu;
struct cpuidle_device *dev =
- per_cpu_ptr(cpuidle_devices, hotcpu);
+ per_cpu(cpuidle_devices, hotcpu);
if (dev && cpuidle_get_driver()) {
switch (action) {
^ permalink raw reply related
* [PATCH v2] mtd: m25p80: Make the name of mtd_info fixed
From: Hou Zhiqiang @ 2014-01-26 6:16 UTC (permalink / raw)
To: linux-mtd, linuxppc-dev
Cc: scottwood, Hou Zhiqiang, mingkai.hu, computersforpeace
To give spi flash layout using "mtdparts=..." in cmdline, we must
give mtd_info a fixed name,because the cmdlinepart's parser will
match the name given in cmdline with the mtd_info.
Now, if use OF node, mtd_info's name will be spi->dev->name. It
consists of spi_master->bus_num, and the spi_master->bus_num maybe
dynamically fetched.
So, give the mtd_info a new fiexd name "name.cs", "name" is name of
spi_device_id and "cs" is chip-select in spi_dev.
Signed-off-by: Hou Zhiqiang <b48286@freescale.com>
---
v2:
- add check for return value of function kasprintf.
- whether the spi_master->bus_num is dynamical is determined by spi
controller driver, and it can't be check in this driver. So, we can
not initial the mtd_info's name by distinguishing the spi_master
bus_num dynamically-allocated or not.
drivers/mtd/devices/m25p80.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c
index eb558e8..1f494d2 100644
--- a/drivers/mtd/devices/m25p80.c
+++ b/drivers/mtd/devices/m25p80.c
@@ -1011,8 +1011,12 @@ static int m25p_probe(struct spi_device *spi)
if (data && data->name)
flash->mtd.name = data->name;
- else
- flash->mtd.name = dev_name(&spi->dev);
+ else {
+ flash->mtd.name = kasprintf(GFP_KERNEL, "%s.%d",
+ id->name, spi->chip_select);
+ if (!flash->mtd.name)
+ return -ENOMEM;
+ }
flash->mtd.type = MTD_NORFLASH;
flash->mtd.writesize = 1;
--
1.8.4.1
^ permalink raw reply related
* Re: [PATCH] slub: Don't throw away partial remote slabs if there is no local memory
From: Joonsoo Kim @ 2014-01-27 5:58 UTC (permalink / raw)
To: Nishanth Aravamudan
Cc: Han Pingtian, mpm, penberg, linux-mm, paulus, Anton Blanchard,
David Rientjes, Christoph Lameter, linuxppc-dev, Wanpeng Li
In-Reply-To: <20140125011041.GB25344@linux.vnet.ibm.com>
On Fri, Jan 24, 2014 at 05:10:42PM -0800, Nishanth Aravamudan wrote:
> On 24.01.2014 [16:25:58 -0800], David Rientjes wrote:
> > On Fri, 24 Jan 2014, Nishanth Aravamudan wrote:
> >
> > > Thank you for clarifying and providing a test patch. I ran with this on
> > > the system showing the original problem, configured to have 15GB of
> > > memory.
> > >
> > > With your patch after boot:
> > >
> > > MemTotal: 15604736 kB
> > > MemFree: 8768192 kB
> > > Slab: 3882560 kB
> > > SReclaimable: 105408 kB
> > > SUnreclaim: 3777152 kB
> > >
> > > With Anton's patch after boot:
> > >
> > > MemTotal: 15604736 kB
> > > MemFree: 11195008 kB
> > > Slab: 1427968 kB
> > > SReclaimable: 109184 kB
> > > SUnreclaim: 1318784 kB
> > >
> > >
> > > I know that's fairly unscientific, but the numbers are reproducible.
> > >
Hello,
I think that there is one mistake on David's patch although I'm not sure
that it is the reason for this result.
With David's patch, get_partial() in new_slab_objects() doesn't work properly,
because we only change node id in !node_match() case. If we meet just !freelist
case, we pass node id directly to new_slab_objects(), so we always try to allocate
new slab page regardless existence of partial pages. We should solve it.
Could you try this one?
Thanks.
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1698,8 +1698,10 @@ static void *get_partial(struct kmem_cache *s, gfp_t flags, int node,
struct kmem_cache_cpu *c)
{
void *object;
- int searchnode = (node == NUMA_NO_NODE) ? numa_node_id() : node;
+ int searchnode = (node == NUMA_NO_NODE) ? numa_mem_id() : node;
+ if (node != NUMA_NO_NODE && !node_present_pages(node))
+ searchnode = numa_mem_id();
object = get_partial_node(s, get_node(s, searchnode), c, flags);
if (object || node != NUMA_NO_NODE)
return object;
@@ -2278,10 +2280,14 @@ redo:
if (unlikely(!node_match(page, node))) {
stat(s, ALLOC_NODE_MISMATCH);
- deactivate_slab(s, page, c->freelist);
- c->page = NULL;
- c->freelist = NULL;
- goto new_slab;
+ if (unlikely(!node_present_pages(node)))
+ node = numa_mem_id();
+ if (!node_match(page, node)) {
+ deactivate_slab(s, page, c->freelist);
+ c->page = NULL;
+ c->freelist = NULL;
+ goto new_slab;
+ }
}
/*
^ permalink raw reply
* [PATCH 0/9] setting the table for integration of cpuidle with the scheduler
From: Nicolas Pitre @ 2014-01-27 6:08 UTC (permalink / raw)
To: Russell King, Catalin Marinas, Benjamin Herrenschmidt, Paul Mundt,
Thomas Gleixner, Ingo Molnar, Peter Zijlstra, Rafael J. Wysocki,
Daniel Lezcano
Cc: linaro-kernel, linux-pm, linux-sh, linux-kernel, linuxppc-dev,
linux-arm-kernel
As everyone should know by now, we want to integrate the cpuidle
governor with the scheduler for a more efficient idling of CPUs.
In order to help the transition, this small patch series moves the
existing interaction with cpuidle from architecture code to generic
core code. No functional change should have occurred yet.
The ARM, PPC, SH and X86 architectures are concerned. Small cleanups
to ARM and ARM64 are also included. I don't know yet the best path for
those patches to get into mainline, but it is probably best if they
stay together. So ACKs from architecture maintainers would be greatly
appreciated.
arch/arm/kernel/process.c | 21 +++---------
arch/arm/kernel/setup.c | 7 ++++
arch/arm64/kernel/process.c | 5 ---
arch/arm64/kernel/setup.c | 7 ++++
arch/powerpc/platforms/pseries/processor_idle.c | 5 +++
arch/powerpc/platforms/pseries/setup.c | 34 ++++++++-----------
arch/sh/kernel/idle.c | 4 +--
arch/x86/kernel/process.c | 5 +--
include/linux/cpu.h | 1 -
kernel/Makefile | 1 -
kernel/cpu/Makefile | 1 -
kernel/sched/Makefile | 2 +-
kernel/{cpu => sched}/idle.c | 6 ++--
13 files changed, 44 insertions(+), 55 deletions(-)
Nicolas
^ permalink raw reply
* [PATCH 1/9] ARM: get rid of arch_cpu_idle_prepare()
From: Nicolas Pitre @ 2014-01-27 6:08 UTC (permalink / raw)
To: Russell King, Catalin Marinas, Benjamin Herrenschmidt, Paul Mundt,
Thomas Gleixner, Ingo Molnar, Peter Zijlstra, Rafael J. Wysocki,
Daniel Lezcano
Cc: linaro-kernel, linux-pm, linux-sh, linux-kernel, linuxppc-dev,
linux-arm-kernel
In-Reply-To: <1390802904-28399-1-git-send-email-nicolas.pitre@linaro.org>
ARM and ARM64 are the only two architectures implementing
arch_cpu_idle_prepare() simply to call local_fiq_enable().
We have secondary_start_kernel() already calling local_fiq_enable() and
this is done a second time in arch_cpu_idle_prepare() in that case. And
enabling FIQs has nothing to do with idling the CPU to start with.
So let's introduce init_fiq_boot_cpu() to take care of FIQs on the boot
CPU and remove arch_cpu_idle_prepare(). This is now done a bit earlier
at late_initcall time but this shouldn't make a difference in practice
i.e. when FIQs are actually used.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
---
arch/arm/kernel/process.c | 5 -----
arch/arm/kernel/setup.c | 7 +++++++
2 files changed, 7 insertions(+), 5 deletions(-)
diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index 92f7b15dd2..725b8c95e0 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -142,11 +142,6 @@ static void default_idle(void)
local_irq_enable();
}
-void arch_cpu_idle_prepare(void)
-{
- local_fiq_enable();
-}
-
void arch_cpu_idle_enter(void)
{
ledtrig_cpu(CPU_LED_IDLE_START);
diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index 987a7f5bce..d027b1a6fe 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -789,6 +789,13 @@ static int __init init_machine_late(void)
}
late_initcall(init_machine_late);
+static int __init init_fiq_boot_cpu(void)
+{
+ local_fiq_enable();
+ return 0;
+}
+late_initcall(init_fiq_boot_cpu);
+
#ifdef CONFIG_KEXEC
static inline unsigned long long get_total_mem(void)
{
--
1.8.4.108.g55ea5f6
^ permalink raw reply related
* [PATCH 2/9] ARM64: get rid of arch_cpu_idle_prepare()
From: Nicolas Pitre @ 2014-01-27 6:08 UTC (permalink / raw)
To: Russell King, Catalin Marinas, Benjamin Herrenschmidt, Paul Mundt,
Thomas Gleixner, Ingo Molnar, Peter Zijlstra, Rafael J. Wysocki,
Daniel Lezcano
Cc: linaro-kernel, linux-pm, linux-sh, linux-kernel, linuxppc-dev,
linux-arm-kernel
In-Reply-To: <1390802904-28399-1-git-send-email-nicolas.pitre@linaro.org>
ARM and ARM64 are the only two architectures implementing
arch_cpu_idle_prepare() simply to call local_fiq_enable().
We have secondary_start_kernel() already calling local_fiq_enable() and
this is done a second time in arch_cpu_idle_prepare() in that case. And
enabling FIQs has nothing to do with idling the CPU to start with.
So let's introduce init_fiq_boot_cpu() to take care of FIQs on the boot
CPU and remove arch_cpu_idle_prepare(). This is now done a bit earlier
at late_initcall time but this shouldn't make a difference in practice
given that FIQs are not currently used on ARM64.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
---
arch/arm64/kernel/process.c | 5 -----
arch/arm64/kernel/setup.c | 7 +++++++
2 files changed, 7 insertions(+), 5 deletions(-)
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
index de17c89985..f6c733da67 100644
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -84,11 +84,6 @@ EXPORT_SYMBOL_GPL(pm_power_off);
void (*arm_pm_restart)(enum reboot_mode reboot_mode, const char *cmd);
EXPORT_SYMBOL_GPL(arm_pm_restart);
-void arch_cpu_idle_prepare(void)
-{
- local_fiq_enable();
-}
-
/*
* This is our default idle handler.
*/
diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
index bd9bbd0e44..259557983a 100644
--- a/arch/arm64/kernel/setup.c
+++ b/arch/arm64/kernel/setup.c
@@ -255,6 +255,13 @@ static int __init arm64_device_init(void)
}
arch_initcall(arm64_device_init);
+static int __init init_fiq_boot_cpu(void)
+{
+ local_fiq_enable();
+ return 0;
+}
+late_initcall(init_fiq_boot_cpu);
+
static DEFINE_PER_CPU(struct cpu, cpu_data);
static int __init topology_init(void)
--
1.8.4.108.g55ea5f6
^ permalink raw reply related
* [PATCH 3/9] idle: no more arch_cpu_idle_prepare() users
From: Nicolas Pitre @ 2014-01-27 6:08 UTC (permalink / raw)
To: Russell King, Catalin Marinas, Benjamin Herrenschmidt, Paul Mundt,
Thomas Gleixner, Ingo Molnar, Peter Zijlstra, Rafael J. Wysocki,
Daniel Lezcano
Cc: linaro-kernel, linux-pm, linux-sh, linux-kernel, linuxppc-dev,
linux-arm-kernel
In-Reply-To: <1390802904-28399-1-git-send-email-nicolas.pitre@linaro.org>
... so we can get rid of it entirely.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
---
include/linux/cpu.h | 1 -
kernel/cpu/idle.c | 2 --
2 files changed, 3 deletions(-)
diff --git a/include/linux/cpu.h b/include/linux/cpu.h
index 03e235ad1b..218fab7521 100644
--- a/include/linux/cpu.h
+++ b/include/linux/cpu.h
@@ -221,7 +221,6 @@ void cpu_idle(void);
void cpu_idle_poll_ctrl(bool enable);
void arch_cpu_idle(void);
-void arch_cpu_idle_prepare(void);
void arch_cpu_idle_enter(void);
void arch_cpu_idle_exit(void);
void arch_cpu_idle_dead(void);
diff --git a/kernel/cpu/idle.c b/kernel/cpu/idle.c
index 988573a9a3..4e327e211b 100644
--- a/kernel/cpu/idle.c
+++ b/kernel/cpu/idle.c
@@ -52,7 +52,6 @@ static inline int cpu_idle_poll(void)
}
/* Weak implementations for optional arch specific functions */
-void __weak arch_cpu_idle_prepare(void) { }
void __weak arch_cpu_idle_enter(void) { }
void __weak arch_cpu_idle_exit(void) { }
void __weak arch_cpu_idle_dead(void) { }
@@ -136,6 +135,5 @@ void cpu_startup_entry(enum cpuhp_state state)
boot_init_stack_canary();
#endif
__current_set_polling();
- arch_cpu_idle_prepare();
cpu_idle_loop();
}
--
1.8.4.108.g55ea5f6
^ permalink raw reply related
* [PATCH 4/9] idle: move the cpuidle entry point to the generic idle loop
From: Nicolas Pitre @ 2014-01-27 6:08 UTC (permalink / raw)
To: Russell King, Catalin Marinas, Benjamin Herrenschmidt, Paul Mundt,
Thomas Gleixner, Ingo Molnar, Peter Zijlstra, Rafael J. Wysocki,
Daniel Lezcano
Cc: linaro-kernel, linux-pm, linux-sh, linux-kernel, linuxppc-dev,
linux-arm-kernel
In-Reply-To: <1390802904-28399-1-git-send-email-nicolas.pitre@linaro.org>
In order to integrate cpuidle with the scheduler, we must have a better
proximity in the core code with what cpuidle is doing and not delegate
such interaction to arch code.
Architectures implementing arch_cpu_idle() should simply enter
a cheap idle mode in the absence of a proper cpuidle driver.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
---
kernel/cpu/idle.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/kernel/cpu/idle.c b/kernel/cpu/idle.c
index 4e327e211b..a6f40ad9f8 100644
--- a/kernel/cpu/idle.c
+++ b/kernel/cpu/idle.c
@@ -3,6 +3,7 @@
*/
#include <linux/sched.h>
#include <linux/cpu.h>
+#include <linux/cpuidle.h>
#include <linux/tick.h>
#include <linux/mm.h>
#include <linux/stackprotector.h>
@@ -94,7 +95,8 @@ static void cpu_idle_loop(void)
if (!current_clr_polling_and_test()) {
stop_critical_timings();
rcu_idle_enter();
- arch_cpu_idle();
+ if (cpuidle_idle_call())
+ arch_cpu_idle();
WARN_ON_ONCE(irqs_disabled());
rcu_idle_exit();
start_critical_timings();
--
1.8.4.108.g55ea5f6
^ permalink raw reply related
* [PATCH 5/9] ARM: remove redundant cpuidle_idle_call()
From: Nicolas Pitre @ 2014-01-27 6:08 UTC (permalink / raw)
To: Russell King, Catalin Marinas, Benjamin Herrenschmidt, Paul Mundt,
Thomas Gleixner, Ingo Molnar, Peter Zijlstra, Rafael J. Wysocki,
Daniel Lezcano
Cc: linaro-kernel, linux-pm, linux-sh, linux-kernel, linuxppc-dev,
linux-arm-kernel
In-Reply-To: <1390802904-28399-1-git-send-email-nicolas.pitre@linaro.org>
The core idle loop now takes care of it.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
---
arch/arm/kernel/process.c | 16 +++++-----------
1 file changed, 5 insertions(+), 11 deletions(-)
diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index 725b8c95e0..34a59b7614 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -30,7 +30,6 @@
#include <linux/uaccess.h>
#include <linux/random.h>
#include <linux/hw_breakpoint.h>
-#include <linux/cpuidle.h>
#include <linux/leds.h>
#include <linux/reboot.h>
@@ -133,7 +132,11 @@ EXPORT_SYMBOL_GPL(arm_pm_restart);
void (*arm_pm_idle)(void);
-static void default_idle(void)
+/*
+ * Called from the core idle loop.
+ */
+
+void arch_cpu_idle(void)
{
if (arm_pm_idle)
arm_pm_idle();
@@ -163,15 +166,6 @@ void arch_cpu_idle_dead(void)
#endif
/*
- * Called from the core idle loop.
- */
-void arch_cpu_idle(void)
-{
- if (cpuidle_idle_call())
- default_idle();
-}
-
-/*
* Called by kexec, immediately prior to machine_kexec().
*
* This must completely disable all secondary CPUs; simply causing those CPUs
--
1.8.4.108.g55ea5f6
^ permalink raw reply related
* [PATCH 7/9] SH: remove redundant cpuidle_idle_call()
From: Nicolas Pitre @ 2014-01-27 6:08 UTC (permalink / raw)
To: Russell King, Catalin Marinas, Benjamin Herrenschmidt, Paul Mundt,
Thomas Gleixner, Ingo Molnar, Peter Zijlstra, Rafael J. Wysocki,
Daniel Lezcano
Cc: linaro-kernel, linux-pm, linux-sh, linux-kernel, linuxppc-dev,
linux-arm-kernel
In-Reply-To: <1390802904-28399-1-git-send-email-nicolas.pitre@linaro.org>
The core idle loop now takes care of it.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
---
arch/sh/kernel/idle.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/arch/sh/kernel/idle.c b/arch/sh/kernel/idle.c
index 2ea4483fd7..be616ee0cf 100644
--- a/arch/sh/kernel/idle.c
+++ b/arch/sh/kernel/idle.c
@@ -16,7 +16,6 @@
#include <linux/thread_info.h>
#include <linux/irqflags.h>
#include <linux/smp.h>
-#include <linux/cpuidle.h>
#include <linux/atomic.h>
#include <asm/pgalloc.h>
#include <asm/smp.h>
@@ -40,8 +39,7 @@ void arch_cpu_idle_dead(void)
void arch_cpu_idle(void)
{
- if (cpuidle_idle_call())
- sh_idle();
+ sh_idle();
}
void __init select_idle_routine(void)
--
1.8.4.108.g55ea5f6
^ permalink raw reply related
* [PATCH 6/9] PPC: remove redundant cpuidle_idle_call()
From: Nicolas Pitre @ 2014-01-27 6:08 UTC (permalink / raw)
To: Russell King, Catalin Marinas, Benjamin Herrenschmidt, Paul Mundt,
Thomas Gleixner, Ingo Molnar, Peter Zijlstra, Rafael J. Wysocki,
Daniel Lezcano
Cc: linaro-kernel, linux-pm, linux-sh, linux-kernel, linuxppc-dev,
linux-arm-kernel
In-Reply-To: <1390802904-28399-1-git-send-email-nicolas.pitre@linaro.org>
The core idle loop now takes care of it. However a few things need
checking:
- Invocation of cpuidle_idle_call() in pseries_lpar_idle() happened
through arch_cpu_idle() and was therefore always preceded by a call
to ppc64_runlatch_off(). To preserve this property now that
cpuidle_idle_call() is invoked directly from core code, a call to
ppc64_runlatch_off() has been added to idle_loop_prolog() in
platforms/pseries/processor_idle.c.
- Similarly, cpuidle_idle_call() was followed by ppc64_runlatch_off()
so a call to the later has been added to idle_loop_epilog().
- And since arch_cpu_idle() always made sure to re-enable IRQs if they
were not enabled, this is now
done in idle_loop_epilog() as well.
The above was made in order to keep the execution flow close to the
original. I don't know if that was strictly necessary. Someone well
aquainted with the platform details might find some room for possible
optimizations.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
---
arch/powerpc/platforms/pseries/processor_idle.c | 5 ++++
arch/powerpc/platforms/pseries/setup.c | 34 ++++++++++---------------
2 files changed, 19 insertions(+), 20 deletions(-)
diff --git a/arch/powerpc/platforms/pseries/processor_idle.c b/arch/powerpc/platforms/pseries/processor_idle.c
index a166e38bd6..72ddfe3d2f 100644
--- a/arch/powerpc/platforms/pseries/processor_idle.c
+++ b/arch/powerpc/platforms/pseries/processor_idle.c
@@ -33,6 +33,7 @@ static struct cpuidle_state *cpuidle_state_table;
static inline void idle_loop_prolog(unsigned long *in_purr)
{
+ ppc64_runlatch_off();
*in_purr = mfspr(SPRN_PURR);
/*
* Indicate to the HV that we are idle. Now would be
@@ -49,6 +50,10 @@ static inline void idle_loop_epilog(unsigned long in_purr)
wait_cycles += mfspr(SPRN_PURR) - in_purr;
get_lppaca()->wait_state_cycles = cpu_to_be64(wait_cycles);
get_lppaca()->idle = 0;
+
+ if (irqs_disabled())
+ local_irq_enable();
+ ppc64_runlatch_on();
}
static int snooze_loop(struct cpuidle_device *dev,
diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
index c1f1908587..7604c19d54 100644
--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -39,7 +39,6 @@
#include <linux/irq.h>
#include <linux/seq_file.h>
#include <linux/root_dev.h>
-#include <linux/cpuidle.h>
#include <linux/of.h>
#include <linux/kexec.h>
@@ -356,29 +355,24 @@ early_initcall(alloc_dispatch_log_kmem_cache);
static void pseries_lpar_idle(void)
{
- /* This would call on the cpuidle framework, and the back-end pseries
- * driver to go to idle states
+ /*
+ * Default handler to go into low thread priority and possibly
+ * low power mode by cedeing processor to hypervisor
*/
- if (cpuidle_idle_call()) {
- /* On error, execute default handler
- * to go into low thread priority and possibly
- * low power mode by cedeing processor to hypervisor
- */
- /* Indicate to hypervisor that we are idle. */
- get_lppaca()->idle = 1;
+ /* Indicate to hypervisor that we are idle. */
+ get_lppaca()->idle = 1;
- /*
- * Yield the processor to the hypervisor. We return if
- * an external interrupt occurs (which are driven prior
- * to returning here) or if a prod occurs from another
- * processor. When returning here, external interrupts
- * are enabled.
- */
- cede_processor();
+ /*
+ * Yield the processor to the hypervisor. We return if
+ * an external interrupt occurs (which are driven prior
+ * to returning here) or if a prod occurs from another
+ * processor. When returning here, external interrupts
+ * are enabled.
+ */
+ cede_processor();
- get_lppaca()->idle = 0;
- }
+ get_lppaca()->idle = 0;
}
/*
--
1.8.4.108.g55ea5f6
^ permalink raw reply related
* [PATCH 8/9] X86: remove redundant cpuidle_idle_call()
From: Nicolas Pitre @ 2014-01-27 6:08 UTC (permalink / raw)
To: Russell King, Catalin Marinas, Benjamin Herrenschmidt, Paul Mundt,
Thomas Gleixner, Ingo Molnar, Peter Zijlstra, Rafael J. Wysocki,
Daniel Lezcano
Cc: linaro-kernel, linux-pm, linux-sh, linux-kernel, linuxppc-dev,
linux-arm-kernel
In-Reply-To: <1390802904-28399-1-git-send-email-nicolas.pitre@linaro.org>
The core idle loop now takes care of it.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
---
arch/x86/kernel/process.c | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 3fb8d95ab8..4505e2a950 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -298,10 +298,7 @@ void arch_cpu_idle_dead(void)
*/
void arch_cpu_idle(void)
{
- if (cpuidle_idle_call())
- x86_idle();
- else
- local_irq_enable();
+ x86_idle();
}
/*
--
1.8.4.108.g55ea5f6
^ permalink raw reply related
* [PATCH 9/9] cpu/idle.c: move to sched/idle.c
From: Nicolas Pitre @ 2014-01-27 6:08 UTC (permalink / raw)
To: Russell King, Catalin Marinas, Benjamin Herrenschmidt, Paul Mundt,
Thomas Gleixner, Ingo Molnar, Peter Zijlstra, Rafael J. Wysocki,
Daniel Lezcano
Cc: linaro-kernel, linux-pm, linux-sh, linux-kernel, linuxppc-dev,
linux-arm-kernel
In-Reply-To: <1390802904-28399-1-git-send-email-nicolas.pitre@linaro.org>
Integration of cpuidle with the scheduler requires that the idle loop be
closely integrated with the scheduler proper. Moving cpu/idle.c into the
sched directory will allow for a smoother integration, and eliminate a
subdirectory which contained only one source file.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
---
kernel/Makefile | 1 -
kernel/cpu/Makefile | 1 -
kernel/sched/Makefile | 2 +-
kernel/{cpu => sched}/idle.c | 0
4 files changed, 1 insertion(+), 3 deletions(-)
delete mode 100644 kernel/cpu/Makefile
rename kernel/{cpu => sched}/idle.c (100%)
diff --git a/kernel/Makefile b/kernel/Makefile
index bc010ee272..6f1c7e5cfc 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -22,7 +22,6 @@ obj-y += sched/
obj-y += locking/
obj-y += power/
obj-y += printk/
-obj-y += cpu/
obj-y += irq/
obj-y += rcu/
diff --git a/kernel/cpu/Makefile b/kernel/cpu/Makefile
deleted file mode 100644
index 59ab052ef7..0000000000
--- a/kernel/cpu/Makefile
+++ /dev/null
@@ -1 +0,0 @@
-obj-y = idle.o
diff --git a/kernel/sched/Makefile b/kernel/sched/Makefile
index 7b621409cf..ac3e0ea68f 100644
--- a/kernel/sched/Makefile
+++ b/kernel/sched/Makefile
@@ -11,7 +11,7 @@ ifneq ($(CONFIG_SCHED_OMIT_FRAME_POINTER),y)
CFLAGS_core.o := $(PROFILING) -fno-omit-frame-pointer
endif
-obj-y += core.o proc.o clock.o cputime.o idle_task.o fair.o rt.o stop_task.o
+obj-y += core.o proc.o clock.o cputime.o idle_task.o idle.o fair.o rt.o stop_task.o
obj-y += wait.o completion.o
obj-$(CONFIG_SMP) += cpupri.o
obj-$(CONFIG_SCHED_AUTOGROUP) += auto_group.o
diff --git a/kernel/cpu/idle.c b/kernel/sched/idle.c
similarity index 100%
rename from kernel/cpu/idle.c
rename to kernel/sched/idle.c
--
1.8.4.108.g55ea5f6
^ permalink raw reply related
* Re: [PATCH 1/9] ARM: get rid of arch_cpu_idle_prepare()
From: Daniel Lezcano @ 2014-01-27 8:22 UTC (permalink / raw)
To: Nicolas Pitre, Russell King, Catalin Marinas,
Benjamin Herrenschmidt, Paul Mundt, Thomas Gleixner, Ingo Molnar,
Peter Zijlstra, Rafael J. Wysocki
Cc: linaro-kernel, linux-pm, linux-sh, linux-kernel, linuxppc-dev,
linux-arm-kernel
In-Reply-To: <1390802904-28399-2-git-send-email-nicolas.pitre@linaro.org>
On 01/27/2014 07:08 AM, Nicolas Pitre wrote:
> ARM and ARM64 are the only two architectures implementing
> arch_cpu_idle_prepare() simply to call local_fiq_enable().
>
> We have secondary_start_kernel() already calling local_fiq_enable() and
> this is done a second time in arch_cpu_idle_prepare() in that case. And
> enabling FIQs has nothing to do with idling the CPU to start with.
>
> So let's introduce init_fiq_boot_cpu() to take care of FIQs on the boot
> CPU and remove arch_cpu_idle_prepare(). This is now done a bit earlier
> at late_initcall time but this shouldn't make a difference in practice
> i.e. when FIQs are actually used.
>
> Signed-off-by: Nicolas Pitre <nico@linaro.org>
Reviewed-by: Daniel Lezcano <daniel.lezcano@linaro.org>
> ---
> arch/arm/kernel/process.c | 5 -----
> arch/arm/kernel/setup.c | 7 +++++++
> 2 files changed, 7 insertions(+), 5 deletions(-)
>
> diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
> index 92f7b15dd2..725b8c95e0 100644
> --- a/arch/arm/kernel/process.c
> +++ b/arch/arm/kernel/process.c
> @@ -142,11 +142,6 @@ static void default_idle(void)
> local_irq_enable();
> }
>
> -void arch_cpu_idle_prepare(void)
> -{
> - local_fiq_enable();
> -}
> -
> void arch_cpu_idle_enter(void)
> {
> ledtrig_cpu(CPU_LED_IDLE_START);
> diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
> index 987a7f5bce..d027b1a6fe 100644
> --- a/arch/arm/kernel/setup.c
> +++ b/arch/arm/kernel/setup.c
> @@ -789,6 +789,13 @@ static int __init init_machine_late(void)
> }
> late_initcall(init_machine_late);
>
> +static int __init init_fiq_boot_cpu(void)
> +{
> + local_fiq_enable();
> + return 0;
> +}
> +late_initcall(init_fiq_boot_cpu);
> +
> #ifdef CONFIG_KEXEC
> static inline unsigned long long get_total_mem(void)
> {
>
--
<http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs
Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook |
<http://twitter.com/#!/linaroorg> Twitter |
<http://www.linaro.org/linaro-blog/> Blog
^ permalink raw reply
* Re: [PATCH 2/9] ARM64: get rid of arch_cpu_idle_prepare()
From: Daniel Lezcano @ 2014-01-27 8:23 UTC (permalink / raw)
To: Nicolas Pitre, Russell King, Catalin Marinas,
Benjamin Herrenschmidt, Paul Mundt, Thomas Gleixner, Ingo Molnar,
Peter Zijlstra, Rafael J. Wysocki
Cc: linaro-kernel, linux-pm, linux-sh, linux-kernel, linuxppc-dev,
linux-arm-kernel
In-Reply-To: <1390802904-28399-3-git-send-email-nicolas.pitre@linaro.org>
On 01/27/2014 07:08 AM, Nicolas Pitre wrote:
> ARM and ARM64 are the only two architectures implementing
> arch_cpu_idle_prepare() simply to call local_fiq_enable().
>
> We have secondary_start_kernel() already calling local_fiq_enable() and
> this is done a second time in arch_cpu_idle_prepare() in that case. And
> enabling FIQs has nothing to do with idling the CPU to start with.
>
> So let's introduce init_fiq_boot_cpu() to take care of FIQs on the boot
> CPU and remove arch_cpu_idle_prepare(). This is now done a bit earlier
> at late_initcall time but this shouldn't make a difference in practice
> given that FIQs are not currently used on ARM64.
>
> Signed-off-by: Nicolas Pitre <nico@linaro.org>
Reviewed-by: Daniel Lezcano <daniel.lezcano@linaro.org>
> ---
> arch/arm64/kernel/process.c | 5 -----
> arch/arm64/kernel/setup.c | 7 +++++++
> 2 files changed, 7 insertions(+), 5 deletions(-)
>
> diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
> index de17c89985..f6c733da67 100644
> --- a/arch/arm64/kernel/process.c
> +++ b/arch/arm64/kernel/process.c
> @@ -84,11 +84,6 @@ EXPORT_SYMBOL_GPL(pm_power_off);
> void (*arm_pm_restart)(enum reboot_mode reboot_mode, const char *cmd);
> EXPORT_SYMBOL_GPL(arm_pm_restart);
>
> -void arch_cpu_idle_prepare(void)
> -{
> - local_fiq_enable();
> -}
> -
> /*
> * This is our default idle handler.
> */
> diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
> index bd9bbd0e44..259557983a 100644
> --- a/arch/arm64/kernel/setup.c
> +++ b/arch/arm64/kernel/setup.c
> @@ -255,6 +255,13 @@ static int __init arm64_device_init(void)
> }
> arch_initcall(arm64_device_init);
>
> +static int __init init_fiq_boot_cpu(void)
> +{
> + local_fiq_enable();
> + return 0;
> +}
> +late_initcall(init_fiq_boot_cpu);
> +
> static DEFINE_PER_CPU(struct cpu, cpu_data);
>
> static int __init topology_init(void)
>
--
<http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs
Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook |
<http://twitter.com/#!/linaroorg> Twitter |
<http://www.linaro.org/linaro-blog/> Blog
^ permalink raw reply
* Re: [PATCH 3/9] idle: no more arch_cpu_idle_prepare() users
From: Daniel Lezcano @ 2014-01-27 8:24 UTC (permalink / raw)
To: Nicolas Pitre, Russell King, Catalin Marinas,
Benjamin Herrenschmidt, Paul Mundt, Thomas Gleixner, Ingo Molnar,
Peter Zijlstra, Rafael J. Wysocki
Cc: linaro-kernel, linux-pm, linux-sh, linux-kernel, linuxppc-dev,
linux-arm-kernel
In-Reply-To: <1390802904-28399-4-git-send-email-nicolas.pitre@linaro.org>
On 01/27/2014 07:08 AM, Nicolas Pitre wrote:
> ... so we can get rid of it entirely.
>
> Signed-off-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
> ---
> include/linux/cpu.h | 1 -
> kernel/cpu/idle.c | 2 --
> 2 files changed, 3 deletions(-)
>
> diff --git a/include/linux/cpu.h b/include/linux/cpu.h
> index 03e235ad1b..218fab7521 100644
> --- a/include/linux/cpu.h
> +++ b/include/linux/cpu.h
> @@ -221,7 +221,6 @@ void cpu_idle(void);
> void cpu_idle_poll_ctrl(bool enable);
>
> void arch_cpu_idle(void);
> -void arch_cpu_idle_prepare(void);
> void arch_cpu_idle_enter(void);
> void arch_cpu_idle_exit(void);
> void arch_cpu_idle_dead(void);
> diff --git a/kernel/cpu/idle.c b/kernel/cpu/idle.c
> index 988573a9a3..4e327e211b 100644
> --- a/kernel/cpu/idle.c
> +++ b/kernel/cpu/idle.c
> @@ -52,7 +52,6 @@ static inline int cpu_idle_poll(void)
> }
>
> /* Weak implementations for optional arch specific functions */
> -void __weak arch_cpu_idle_prepare(void) { }
> void __weak arch_cpu_idle_enter(void) { }
> void __weak arch_cpu_idle_exit(void) { }
> void __weak arch_cpu_idle_dead(void) { }
> @@ -136,6 +135,5 @@ void cpu_startup_entry(enum cpuhp_state state)
> boot_init_stack_canary();
> #endif
> __current_set_polling();
> - arch_cpu_idle_prepare();
> cpu_idle_loop();
> }
>
--
<http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs
Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook |
<http://twitter.com/#!/linaroorg> Twitter |
<http://www.linaro.org/linaro-blog/> Blog
^ permalink raw reply
* Re: [PATCH 4/9] idle: move the cpuidle entry point to the generic idle loop
From: Daniel Lezcano @ 2014-01-27 8:32 UTC (permalink / raw)
To: Nicolas Pitre, Russell King, Catalin Marinas,
Benjamin Herrenschmidt, Paul Mundt, Thomas Gleixner, Ingo Molnar,
Peter Zijlstra, Rafael J. Wysocki
Cc: linaro-kernel, linux-pm, linux-sh, linux-kernel, linuxppc-dev,
linux-arm-kernel
In-Reply-To: <1390802904-28399-5-git-send-email-nicolas.pitre@linaro.org>
On 01/27/2014 07:08 AM, Nicolas Pitre wrote:
> In order to integrate cpuidle with the scheduler, we must have a better
> proximity in the core code with what cpuidle is doing and not delegate
> such interaction to arch code.
>
> Architectures implementing arch_cpu_idle() should simply enter
> a cheap idle mode in the absence of a proper cpuidle driver.
>
> Signed-off-by: Nicolas Pitre <nico@linaro.org>
This patch without the next ones will lead to an extra call to
cpuidle_idle_call.
cpuidle_idle_call
arch_cpu_idle
cpuidle_idle_call
x86_idle
But I guess it is acceptable as it is fixed with the next patches of the
serie.
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
> ---
> kernel/cpu/idle.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/kernel/cpu/idle.c b/kernel/cpu/idle.c
> index 4e327e211b..a6f40ad9f8 100644
> --- a/kernel/cpu/idle.c
> +++ b/kernel/cpu/idle.c
> @@ -3,6 +3,7 @@
> */
> #include <linux/sched.h>
> #include <linux/cpu.h>
> +#include <linux/cpuidle.h>
> #include <linux/tick.h>
> #include <linux/mm.h>
> #include <linux/stackprotector.h>
> @@ -94,7 +95,8 @@ static void cpu_idle_loop(void)
> if (!current_clr_polling_and_test()) {
> stop_critical_timings();
> rcu_idle_enter();
> - arch_cpu_idle();
> + if (cpuidle_idle_call())
> + arch_cpu_idle();
> WARN_ON_ONCE(irqs_disabled());
> rcu_idle_exit();
> start_critical_timings();
>
--
<http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs
Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook |
<http://twitter.com/#!/linaroorg> Twitter |
<http://www.linaro.org/linaro-blog/> Blog
^ permalink raw reply
* Re: [PATCH 5/9] ARM: remove redundant cpuidle_idle_call()
From: Daniel Lezcano @ 2014-01-27 8:33 UTC (permalink / raw)
To: Nicolas Pitre, Russell King, Catalin Marinas,
Benjamin Herrenschmidt, Paul Mundt, Thomas Gleixner, Ingo Molnar,
Peter Zijlstra, Rafael J. Wysocki
Cc: linaro-kernel, linux-pm, linux-sh, linux-kernel, linuxppc-dev,
linux-arm-kernel
In-Reply-To: <1390802904-28399-6-git-send-email-nicolas.pitre@linaro.org>
On 01/27/2014 07:08 AM, Nicolas Pitre wrote:
> The core idle loop now takes care of it.
>
> Signed-off-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
> ---
> arch/arm/kernel/process.c | 16 +++++-----------
> 1 file changed, 5 insertions(+), 11 deletions(-)
>
> diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
> index 725b8c95e0..34a59b7614 100644
> --- a/arch/arm/kernel/process.c
> +++ b/arch/arm/kernel/process.c
> @@ -30,7 +30,6 @@
> #include <linux/uaccess.h>
> #include <linux/random.h>
> #include <linux/hw_breakpoint.h>
> -#include <linux/cpuidle.h>
> #include <linux/leds.h>
> #include <linux/reboot.h>
>
> @@ -133,7 +132,11 @@ EXPORT_SYMBOL_GPL(arm_pm_restart);
>
> void (*arm_pm_idle)(void);
>
> -static void default_idle(void)
> +/*
> + * Called from the core idle loop.
> + */
> +
> +void arch_cpu_idle(void)
> {
> if (arm_pm_idle)
> arm_pm_idle();
> @@ -163,15 +166,6 @@ void arch_cpu_idle_dead(void)
> #endif
>
> /*
> - * Called from the core idle loop.
> - */
> -void arch_cpu_idle(void)
> -{
> - if (cpuidle_idle_call())
> - default_idle();
> -}
> -
> -/*
> * Called by kexec, immediately prior to machine_kexec().
> *
> * This must completely disable all secondary CPUs; simply causing those CPUs
>
--
<http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs
Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook |
<http://twitter.com/#!/linaroorg> Twitter |
<http://www.linaro.org/linaro-blog/> Blog
^ permalink raw reply
* Re: [PATCH 6/9] PPC: remove redundant cpuidle_idle_call()
From: Daniel Lezcano @ 2014-01-27 8:35 UTC (permalink / raw)
To: Nicolas Pitre, Russell King, Catalin Marinas,
Benjamin Herrenschmidt, Paul Mundt, Thomas Gleixner, Ingo Molnar,
Peter Zijlstra, Rafael J. Wysocki
Cc: linaro-kernel, linux-pm, linux-sh, linux-kernel, Preeti U Murthy,
linuxppc-dev, linux-arm-kernel
In-Reply-To: <1390802904-28399-7-git-send-email-nicolas.pitre@linaro.org>
On 01/27/2014 07:08 AM, Nicolas Pitre wrote:
> The core idle loop now takes care of it. However a few things need
> checking:
>
> - Invocation of cpuidle_idle_call() in pseries_lpar_idle() happened
> through arch_cpu_idle() and was therefore always preceded by a call
> to ppc64_runlatch_off(). To preserve this property now that
> cpuidle_idle_call() is invoked directly from core code, a call to
> ppc64_runlatch_off() has been added to idle_loop_prolog() in
> platforms/pseries/processor_idle.c.
>
> - Similarly, cpuidle_idle_call() was followed by ppc64_runlatch_off()
> so a call to the later has been added to idle_loop_epilog().
>
> - And since arch_cpu_idle() always made sure to re-enable IRQs if they
> were not enabled, this is now
> done in idle_loop_epilog() as well.
>
> The above was made in order to keep the execution flow close to the
> original. I don't know if that was strictly necessary. Someone well
> aquainted with the platform details might find some room for possible
> optimizations.
>
> Signed-off-by: Nicolas Pitre <nico@linaro.org>
Added Preeti U Murthy as recipient.
> ---
> arch/powerpc/platforms/pseries/processor_idle.c | 5 ++++
> arch/powerpc/platforms/pseries/setup.c | 34 ++++++++++---------------
> 2 files changed, 19 insertions(+), 20 deletions(-)
>
> diff --git a/arch/powerpc/platforms/pseries/processor_idle.c b/arch/powerpc/platforms/pseries/processor_idle.c
> index a166e38bd6..72ddfe3d2f 100644
> --- a/arch/powerpc/platforms/pseries/processor_idle.c
> +++ b/arch/powerpc/platforms/pseries/processor_idle.c
> @@ -33,6 +33,7 @@ static struct cpuidle_state *cpuidle_state_table;
>
> static inline void idle_loop_prolog(unsigned long *in_purr)
> {
> + ppc64_runlatch_off();
> *in_purr = mfspr(SPRN_PURR);
> /*
> * Indicate to the HV that we are idle. Now would be
> @@ -49,6 +50,10 @@ static inline void idle_loop_epilog(unsigned long in_purr)
> wait_cycles += mfspr(SPRN_PURR) - in_purr;
> get_lppaca()->wait_state_cycles = cpu_to_be64(wait_cycles);
> get_lppaca()->idle = 0;
> +
> + if (irqs_disabled())
> + local_irq_enable();
> + ppc64_runlatch_on();
> }
>
> static int snooze_loop(struct cpuidle_device *dev,
> diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
> index c1f1908587..7604c19d54 100644
> --- a/arch/powerpc/platforms/pseries/setup.c
> +++ b/arch/powerpc/platforms/pseries/setup.c
> @@ -39,7 +39,6 @@
> #include <linux/irq.h>
> #include <linux/seq_file.h>
> #include <linux/root_dev.h>
> -#include <linux/cpuidle.h>
> #include <linux/of.h>
> #include <linux/kexec.h>
>
> @@ -356,29 +355,24 @@ early_initcall(alloc_dispatch_log_kmem_cache);
>
> static void pseries_lpar_idle(void)
> {
> - /* This would call on the cpuidle framework, and the back-end pseries
> - * driver to go to idle states
> + /*
> + * Default handler to go into low thread priority and possibly
> + * low power mode by cedeing processor to hypervisor
> */
> - if (cpuidle_idle_call()) {
> - /* On error, execute default handler
> - * to go into low thread priority and possibly
> - * low power mode by cedeing processor to hypervisor
> - */
>
> - /* Indicate to hypervisor that we are idle. */
> - get_lppaca()->idle = 1;
> + /* Indicate to hypervisor that we are idle. */
> + get_lppaca()->idle = 1;
>
> - /*
> - * Yield the processor to the hypervisor. We return if
> - * an external interrupt occurs (which are driven prior
> - * to returning here) or if a prod occurs from another
> - * processor. When returning here, external interrupts
> - * are enabled.
> - */
> - cede_processor();
> + /*
> + * Yield the processor to the hypervisor. We return if
> + * an external interrupt occurs (which are driven prior
> + * to returning here) or if a prod occurs from another
> + * processor. When returning here, external interrupts
> + * are enabled.
> + */
> + cede_processor();
>
> - get_lppaca()->idle = 0;
> - }
> + get_lppaca()->idle = 0;
> }
>
> /*
>
--
<http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs
Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook |
<http://twitter.com/#!/linaroorg> Twitter |
<http://www.linaro.org/linaro-blog/> Blog
^ permalink raw reply
* Re: [PATCH 7/9] SH: remove redundant cpuidle_idle_call()
From: Daniel Lezcano @ 2014-01-27 8:35 UTC (permalink / raw)
To: Nicolas Pitre, Russell King, Catalin Marinas,
Benjamin Herrenschmidt, Paul Mundt, Thomas Gleixner, Ingo Molnar,
Peter Zijlstra, Rafael J. Wysocki
Cc: linaro-kernel, linux-pm, linux-sh, linux-kernel, linuxppc-dev,
linux-arm-kernel
In-Reply-To: <1390802904-28399-8-git-send-email-nicolas.pitre@linaro.org>
On 01/27/2014 07:08 AM, Nicolas Pitre wrote:
> The core idle loop now takes care of it.
>
> Signed-off-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
> ---
> arch/sh/kernel/idle.c | 4 +---
> 1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/arch/sh/kernel/idle.c b/arch/sh/kernel/idle.c
> index 2ea4483fd7..be616ee0cf 100644
> --- a/arch/sh/kernel/idle.c
> +++ b/arch/sh/kernel/idle.c
> @@ -16,7 +16,6 @@
> #include <linux/thread_info.h>
> #include <linux/irqflags.h>
> #include <linux/smp.h>
> -#include <linux/cpuidle.h>
> #include <linux/atomic.h>
> #include <asm/pgalloc.h>
> #include <asm/smp.h>
> @@ -40,8 +39,7 @@ void arch_cpu_idle_dead(void)
>
> void arch_cpu_idle(void)
> {
> - if (cpuidle_idle_call())
> - sh_idle();
> + sh_idle();
> }
>
> void __init select_idle_routine(void)
>
--
<http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs
Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook |
<http://twitter.com/#!/linaroorg> Twitter |
<http://www.linaro.org/linaro-blog/> Blog
^ permalink raw reply
* Re: [PATCH 8/9] X86: remove redundant cpuidle_idle_call()
From: Daniel Lezcano @ 2014-01-27 8:43 UTC (permalink / raw)
To: Nicolas Pitre, Russell King, Catalin Marinas,
Benjamin Herrenschmidt, Paul Mundt, Thomas Gleixner, Ingo Molnar,
Peter Zijlstra, Rafael J. Wysocki
Cc: linaro-kernel, linux-pm, linux-sh, linux-kernel, linuxppc-dev,
linux-arm-kernel
In-Reply-To: <1390802904-28399-9-git-send-email-nicolas.pitre@linaro.org>
On 01/27/2014 07:08 AM, Nicolas Pitre wrote:
> The core idle loop now takes care of it.
>
> Signed-off-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
> ---
> arch/x86/kernel/process.c | 5 +----
> 1 file changed, 1 insertion(+), 4 deletions(-)
>
> diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
> index 3fb8d95ab8..4505e2a950 100644
> --- a/arch/x86/kernel/process.c
> +++ b/arch/x86/kernel/process.c
> @@ -298,10 +298,7 @@ void arch_cpu_idle_dead(void)
> */
> void arch_cpu_idle(void)
> {
> - if (cpuidle_idle_call())
> - x86_idle();
> - else
> - local_irq_enable();
For the record, it was pointless to enable the local irq here because it
is handled by the cpuidle framework when exiting the idle state.
> + x86_idle();
> }
>
> /*
>
--
<http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs
Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook |
<http://twitter.com/#!/linaroorg> Twitter |
<http://www.linaro.org/linaro-blog/> Blog
^ permalink raw reply
* Re: [PATCH v2] powernv: kvm: make _PAGE_NUMA take effect
From: Alexander Graf @ 2014-01-27 9:11 UTC (permalink / raw)
To: Aneesh Kumar K.V
Cc: kvm-devel, kvm-ppc, Paul Mackerras, Liu Ping Fan, linuxppc-dev
In-Reply-To: <8761pdk6x5.fsf@linux.vnet.ibm.com>
On 21.01.2014, at 10:42, Aneesh Kumar K.V =
<aneesh.kumar@linux.vnet.ibm.com> wrote:
> Liu Ping Fan <kernelfans@gmail.com> writes:
>=20
>> To make sure that on host, the pages marked with _PAGE_NUMA result in =
a fault
>> when guest access them, we should force the checking when guest uses =
hypercall
>> to setup hpte.
>>=20
>> Signed-off-by: Liu Ping Fan <pingfank@linux.vnet.ibm.com>
>=20
> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
>=20
> When we mark pte with _PAGE_NUMA we already call =
mmu_notifier_invalidate_range_start and
> mmu_notifier_invalidate_range_end, which will mark existing guest hpte
> entry as HPTE_V_ABSENT. Now we need to do that when we are inserting =
new
> guest hpte entries. This patch does that.=20
So what happens next? We insert a page into the HTAB without =
HPTE_V_VALID set, so the guest will fail to use it. If the guest does an =
H_READ on it it will suddenly turn to V_VALID though?
I might need a crash course in the use of HPTE_V_ABSENT.
Alex
^ permalink raw reply
* Re: [PATCH v2] powernv: kvm: make _PAGE_NUMA take effect
From: Aneesh Kumar K.V @ 2014-01-27 10:28 UTC (permalink / raw)
To: Alexander Graf
Cc: kvm-devel, kvm-ppc, Paul Mackerras, Liu Ping Fan, linuxppc-dev
In-Reply-To: <C4D7ADEA-9CEB-4717-9AFD-CC8EFB18184A@suse.de>
Alexander Graf <agraf@suse.de> writes:
> On 21.01.2014, at 10:42, Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> wrote:
>
>> Liu Ping Fan <kernelfans@gmail.com> writes:
>>
>>> To make sure that on host, the pages marked with _PAGE_NUMA result in a fault
>>> when guest access them, we should force the checking when guest uses hypercall
>>> to setup hpte.
>>>
>>> Signed-off-by: Liu Ping Fan <pingfank@linux.vnet.ibm.com>
>>
>> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
>>
>> When we mark pte with _PAGE_NUMA we already call mmu_notifier_invalidate_range_start and
>> mmu_notifier_invalidate_range_end, which will mark existing guest hpte
>> entry as HPTE_V_ABSENT. Now we need to do that when we are inserting new
>> guest hpte entries. This patch does that.
>
> So what happens next? We insert a page into the HTAB without
> HPTE_V_VALID set, so the guest will fail to use it. If the guest does
> an H_READ on it it will suddenly turn to V_VALID though?
As per the guest the entry is valid, so yes an hread should return a
valid entry. But in real hpte we would mark it not valid.
>
> I might need a crash course in the use of HPTE_V_ABSENT.
When guest tries to access the address, the host will handle the fault.
kvmppc_hpte_hv_fault should give more info
-aneesh
^ permalink raw reply
* Re: [PATCH v2] powernv: kvm: make _PAGE_NUMA take effect
From: Paul Mackerras @ 2014-01-27 10:41 UTC (permalink / raw)
To: Alexander Graf
Cc: kvm-devel, kvm-ppc, Aneesh Kumar K.V, Liu Ping Fan, linuxppc-dev
In-Reply-To: <C4D7ADEA-9CEB-4717-9AFD-CC8EFB18184A@suse.de>
On Mon, Jan 27, 2014 at 10:11:40AM +0100, Alexander Graf wrote:
>
> On 21.01.2014, at 10:42, Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> wrote:
>
> > Liu Ping Fan <kernelfans@gmail.com> writes:
> >
> >> To make sure that on host, the pages marked with _PAGE_NUMA result in a fault
> >> when guest access them, we should force the checking when guest uses hypercall
> >> to setup hpte.
> >>
> >> Signed-off-by: Liu Ping Fan <pingfank@linux.vnet.ibm.com>
> >
> > Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
> >
> > When we mark pte with _PAGE_NUMA we already call mmu_notifier_invalidate_range_start and
> > mmu_notifier_invalidate_range_end, which will mark existing guest hpte
> > entry as HPTE_V_ABSENT. Now we need to do that when we are inserting new
> > guest hpte entries. This patch does that.
>
> So what happens next? We insert a page into the HTAB without HPTE_V_VALID set, so the guest will fail to use it. If the guest does an H_READ on it it will suddenly turn to V_VALID though?
>
> I might need a crash course in the use of HPTE_V_ABSENT.
HPTE_V_ABSENT means present from the point of view of the guest but
not present from the host's point of view, so yes H_READ turns
HPTE_V_ABSENT into HPTE_V_VALID.
Paul.
^ permalink raw reply
* Re: [PATCH v2] powernv: kvm: make _PAGE_NUMA take effect
From: Alexander Graf @ 2014-01-27 10:42 UTC (permalink / raw)
To: Aneesh Kumar K.V
Cc: kvm-devel, kvm-ppc, Paul Mackerras, Liu Ping Fan, linuxppc-dev
In-Reply-To: <87wqhllnvm.fsf@linux.vnet.ibm.com>
On 27.01.2014, at 11:28, Aneesh Kumar K.V =
<aneesh.kumar@linux.vnet.ibm.com> wrote:
> Alexander Graf <agraf@suse.de> writes:
>=20
>> On 21.01.2014, at 10:42, Aneesh Kumar K.V =
<aneesh.kumar@linux.vnet.ibm.com> wrote:
>>=20
>>> Liu Ping Fan <kernelfans@gmail.com> writes:
>>>=20
>>>> To make sure that on host, the pages marked with _PAGE_NUMA result =
in a fault
>>>> when guest access them, we should force the checking when guest =
uses hypercall
>>>> to setup hpte.
>>>>=20
>>>> Signed-off-by: Liu Ping Fan <pingfank@linux.vnet.ibm.com>
>>>=20
>>> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
>>>=20
>>> When we mark pte with _PAGE_NUMA we already call =
mmu_notifier_invalidate_range_start and
>>> mmu_notifier_invalidate_range_end, which will mark existing guest =
hpte
>>> entry as HPTE_V_ABSENT. Now we need to do that when we are inserting =
new
>>> guest hpte entries. This patch does that.=20
>>=20
>> So what happens next? We insert a page into the HTAB without
>> HPTE_V_VALID set, so the guest will fail to use it. If the guest does
>> an H_READ on it it will suddenly turn to V_VALID though?
>=20
> As per the guest the entry is valid, so yes an hread should return a
> valid entry. But in real hpte we would mark it not valid.
Ah, yes.
>=20
>>=20
>> I might need a crash course in the use of HPTE_V_ABSENT.
>=20
> When guest tries to access the address, the host will handle the =
fault.
>=20
> kvmppc_hpte_hv_fault should give more info
Thanks for the pointer. So we fault it in lazily. Is there any =
particular reason we can't do that on h_enter already? After all this =
just means an additional roundtrip because the guest is pretty likely to =
use the page it just entered, no?
Alex
^ permalink raw reply
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