Hi Santosh,
This seems to have gone from v4 to v6 -- did I miss v5?
On 2017/10/10 11:10PM, Santosh Sivaraj wrote:
> Current vDSO64 implementation does not have support for coarse clocks
> (CLOCK_MONOTONIC_COARSE, CLOCK_REALTIME_COARSE), for which it falls back
> to system call, increasing the resp
* Naveen N. Rao wrote (on 2017-10-11 07:04:43
+):
> Hi Santosh,
> This seems to have gone from v4 to v6 -- did I miss v5?
Nope, this is indeed v5, a typo :-(
>
> On 2017/10/10 11:10PM, Santosh Sivaraj wrote:
> > Current vDSO64 implementation does not have support for coarse clocks
> > (CLOC
Current vDSO64 implementation does not have support for coarse clocks
(CLOCK_MONOTONIC_COARSE, CLOCK_REALTIME_COARSE), for which it falls back
to system call, increasing the response time, vDSO implementation reduces
the cycle time. Below is a benchmark of the difference in execution times.
(Non-c
On 2017/10/11 08:35AM, Santosh Sivaraj wrote:
> Current vDSO64 implementation does not have support for coarse clocks
> (CLOCK_MONOTONIC_COARSE, CLOCK_REALTIME_COARSE), for which it falls back
> to system call, increasing the response time, vDSO implementation reduces
> the cycle time. Below is a b
Hi mpe, stewart,
On Wednesday 11 October 2017 01:55 AM, Stewart Smith wrote:
Michael Ellerman writes:
Anju T Sudhakar writes:
Add a kernel command line parameter option to disable In-Memory Collection
(IMC) counters and add documentation. This helps in debug.
I'd really rather we didn't.
Le 11/10/2017 à 08:14, Vaibhav Jain a écrit :
For PSL9 currently we aren't dumping the PSL FIR register when a
PSL error interrupt is triggered. Contents of this register are useful
in debugging AFU issues.
This patch fixes issue by adding a new service_layer_ops callback
cxl_native_err_irq_du
On 10/10/2017 23:23, Andrew Morton wrote:
> On Mon, 9 Oct 2017 12:07:51 +0200 Laurent Dufour
> wrote:
>
>> +/*
>> + * Advertise that we call the Speculative Page Fault handler.
>> + */
>> +#if defined(CONFIG_X86_64) && defined(CONFIG_SMP)
>> +#define __HAVE_ARCH_CALL_SPF
>> +#endif
>
> Here's
On Friday 06 October 2017 11:13 AM, Kamalesh Babulal wrote:
On Thursday 05 October 2017 06:13 PM, Torsten Duwe wrote:
On Wed, Oct 04, 2017 at 11:25:16AM -0400, Kamalesh Babulal wrote:
Both the failures with REL24 livepatch symbols relocation, can be
resolved by constructing a new livepatch stu
On Wed 2017-10-04 16:27:05, Kees Cook wrote:
> The expires field is normally initialized during the first mod_timer()
> call. It was unused by all callers, so remove it from the macro.
>
> Signed-off-by: Kees Cook
> ---
> include/linux/kthread.h | 2 +-
> include/linux/timer.h | 5 ++---
>
On Wed 2017-10-04 16:27:06, Kees Cook wrote:
> In preparation for unconditionally passing the struct timer_list pointer
> to all timer callbacks, switch kthread to use from_timer() and pass the
> timer pointer explicitly.
>
> Cc: Andrew Morton
> Cc: Petr Mladek
> Cc: Tejun Heo
> Cc: Thomas Glei
Ram Pai writes:
> Currently protection key feature is erroneously configured to
> be enabled for any flavor of PPC64. This patch fixes it.
>
> Signed-off-by: Ram Pai
> ---
> arch/powerpc/Kconfig |2 +-
> 1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/arch/powerpc/Kconfig
Nicholas Piggin writes:
> On Wed, 11 Oct 2017 01:58:28 +1000
> Nicholas Piggin wrote:
>
>
>> Ahh okay, pseries is using the start-cpu RTAS call to enter at
>> generic_secondary_smp_init() as well. So we can take it out for
>> pseries as well.
>
> This patch seems to do the trick for pseries gues
For PSL9 currently we aren't dumping the PSL FIR register when a
PSL error interrupt is triggered. Contents of this register are useful
in debugging AFU issues.
This patch fixes issue by adding a new service_layer_ops callback
cxl_native_err_irq_dump_regs_psl9() to dump the PSL_FIR registers on a
Presently the PSL9 specific cxl_stop_trace_psl9() only stops the RX0
traces on the CXL adapter when a PSL error irq is triggered. The patch
updates the function to stop all the traces arrays and move them to
the FIN state. The implementation issues the mmio to TRACECFG register
to stop the trace ar
Stack trace output during a stress test:
[4.310049] Freeing initrd memory: 22592K
[4.310646] rtas_flash: no firmware flash support
[4.313341] cpuhp/64: page allocation failure: order:0,
mode:0x14480c0(GFP_KERNEL|__GFP_ZERO|__GFP_THISNODE), nodemask=(null)
[4.313465] cpuhp/64 cpuse
On 11/10/17 17:14, Vaibhav Jain wrote:
For PSL9 currently we aren't dumping the PSL FIR register when a
PSL error interrupt is triggered. Contents of this register are useful
in debugging AFU issues.
This patch fixes issue by adding a new service_layer_ops callback
cxl_native_err_irq_dump_regs_p
This is a port on kernel 4.14 of the work done by Peter Zijlstra to
handle page fault without holding the mm semaphore [1].
The idea is to try to handle user space page faults without holding the
mmap_sem. This should allow better concurrency for massively threaded
process since the page fault han
Introduce CONFIG_SPF which turns on the Speculative Page Fault handler when
building for 64bits with SMP.
Signed-off-by: Laurent Dufour
---
arch/x86/Kconfig | 4
1 file changed, 4 insertions(+)
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 063f1e0d51aa..a726618b7018 100644
--- a/a
Define CONFIG_SPF for BOOK3S_64 and SMP. This enables the Speculative Page
Fault handler.
Support is only provide for BOOK3S_64 currently because:
- require CONFIG_PPC_STD_MMU because checks done in
set_access_flags_filter()
- require BOOK3S because we can't support for book3e_hugetlb_preload()
From: Peter Zijlstra
One of the side effects of speculating on faults (without holding
mmap_sem) is that we can race with free_pgtables() and therefore we
cannot assume the page-tables will stick around.
Remove the reliance on the pte pointer.
Signed-off-by: Peter Zijlstra (Intel)
[Remove onl
From: Peter Zijlstra
When speculating faults (without holding mmap_sem) we need to validate
that the vma against which we loaded pages is still valid when we're
ready to install the new PTE.
Therefore, replace the pte_offset_map_lock() calls that (re)take the
PTL with pte_map_lock() which can fa
When handling page fault without holding the mmap_sem the fetch of the
pte lock pointer and the locking will have to be done while ensuring
that the VMA is not touched in our back.
So move the fetch and locking operations in a dedicated function.
Signed-off-by: Laurent Dufour
---
mm/memory.c |
From: Peter Zijlstra
Wrap the VMA modifications (vma_adjust/unmap_page_range) with sequence
counts such that we can easily test if a VMA is changed.
The unmap_page_range() one allows us to make assumptions about
page-tables; when we find the seqcount hasn't changed we can assume
page-tables are
From: Peter Zijlstra
Manage the VMAs with SRCU such that we can do a lockless VMA lookup.
We put the fput(vma->vm_file) in the SRCU callback, this keeps files
valid during speculative faults, this is possible due to the delayed
fput work by Al Viro -- do we need srcu_barrier() in unmount
somepla
The VMA sequence count has been introduced to allow fast detection of
VMA modification when running a page fault handler without holding
the mmap_sem.
This patch provides protection against the VMA modification done in :
- madvise()
- mremap()
- mpol_rebind_policy()
When handling speculative page fault, the vma->vm_flags and
vma->vm_page_prot fields are read once the page table lock is released. So
there is no more guarantee that these fields would not change in our back.
They will be saved in the vm_fault structure before the VMA is checked for
changes.
This
The speculative page fault handler must be protected against anon_vma
changes. This is because page_add_new_anon_rmap() is called during the
speculative path.
In addition, don't try speculative page fault if the VMA don't have an
anon_vma structure allocated because its allocation should be
protec
migrate_misplaced_page() is only called during the page fault handling so
it's better to pass the pointer to the struct vm_fault instead of the vma.
This way during the speculative page fault path the saved vma->vm_flags
could be used.
Signed-off-by: Laurent Dufour
---
include/linux/migrate.h |
The speculative page fault handler which is run without holding the
mmap_sem is calling lru_cache_add_active_or_unevictable() but the vm_flags
is not guaranteed to remain constant.
Introducing __lru_cache_add_active_or_unevictable() which has the vma flags
value parameter instead of the vma pointer
The current maybe_mkwrite() is getting passed the pointer to the vma
structure to fetch the vm_flags field.
When dealing with the speculative page fault handler, it will be better to
rely on the cached vm_flags value stored in the vm_fault structure.
This patch introduce a __maybe_mkwrite() servi
When dealing with the speculative fault path we should use the VMA's field
cached value stored in the vm_fault structure.
Currently vm_normal_page() is using the pointer to the VMA to fetch the
vm_flags value. This patch provides a new __vm_normal_page() which is
receiving the vm_flags flags value
When dealing with speculative page fault handler, we may race with VMA
being split or merged. In this case the vma->vm_start and vm->vm_end
fields may not match the address the page fault is occurring.
This can only happens when the VMA is split but in that case, the
anon_vma pointer of the new VM
From: Peter Zijlstra
Provide infrastructure to do a speculative fault (not holding
mmap_sem).
The not holding of mmap_sem means we can race against VMA
change/removal and page-table destruction. We use the SRCU VMA freeing
to keep the VMA around. We use the VMA seqcount to detect change
(includi
There is a deadlock when a CPU is doing a speculative page fault and
another one is calling do_unmap().
The deadlock occurred because the speculative path try to spinlock the
pte while the interrupt are disabled. When the other CPU in the
unmap's path has locked the pte then is waiting for all the
This patch a set of new trace events to collect the speculative page fault
event failures.
Signed-off-by: Laurent Dufour
---
include/trace/events/pagefault.h | 87
mm/memory.c | 59 ++-
2 files changed, 135 ins
Add a new software event to count succeeded speculative page faults.
Signed-off-by: Laurent Dufour
---
include/uapi/linux/perf_event.h | 1 +
1 file changed, 1 insertion(+)
diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h
index 140ae638cfd6..101e509ee39b 100644
---
Add support for the new speculative faults event.
Signed-off-by: Laurent Dufour
---
tools/include/uapi/linux/perf_event.h | 1 +
tools/perf/util/evsel.c | 1 +
tools/perf/util/parse-events.c| 4
tools/perf/util/parse-events.l| 1 +
tools/perf/util/python.c
From: Peter Zijlstra
Try a speculative fault before acquiring mmap_sem, if it returns with
VM_FAULT_RETRY continue with the mmap_sem acquisition and do the
traditional fault.
Signed-off-by: Peter Zijlstra (Intel)
[Clearing of FAULT_FLAG_ALLOW_RETRY is now done in
handle_speculative_fault()]
[
This patch enable the speculative page fault on the PowerPC
architecture.
This will try a speculative page fault without holding the mmap_sem,
if it returns with VM_FAULT_RETRY, the mmap_sem is acquired and the
traditional page fault processing is done.
Build on if CONFIG_SPF is defined (currentl
On Wed, 11 Oct 2017 22:27:23 +1100
Michael Ellerman wrote:
> Nicholas Piggin writes:
>
> > On Wed, 11 Oct 2017 01:58:28 +1000
> > Nicholas Piggin wrote:
> >
> >
> >> Ahh okay, pseries is using the start-cpu RTAS call to enter at
> >> generic_secondary_smp_init() as well. So we can take it ou
Hi,
On Wed, Oct 11, 2017 at 02:05:02PM +0530, Santosh Sivaraj wrote:
> +70: ld r8,CFG_TB_UPDATE_COUNT(r3)
> + andi. r0,r8,1 /* pending update ? loop */
> + bne-70b
> + xor r0,r8,r8/* create dependency */
r0 already is 0 here, and already
On Tue, Sep 19, 2017 at 05:26:53PM +0800, Zhiqiang Hou wrote:
> From: Hou Zhiqiang
>
> This patch set adds ls1012a MSI and PCIe support, including driver
> and device tree nodes. The ls1046a's MSI support patch and PCIe
> driver patch has been applied, so only adds the PCIe device tree
> nodes.
>
On Fri, Sep 22, 2017 at 09:19:28AM -0500, Bryant G. Ly wrote:
> This patch adds the machine dependent call for
> pcibios_bus_add_device, since the previous patch
> separated the calls out between the PowerNV and PowerVM.
>
> The difference here is that for the PowerVM environment
> we do not want
On Fri, Sep 22, 2017 at 09:19:26AM -0500, Bryant G. Ly wrote:
> This patch series is to prepare for enabling SR-IOV
> on pseries. It separates the calls to be machine dependent
> and does not change any current functionality.
>
> The patch linked below which is currently in review is a dependency:
On Sunday, October 8, 2017 2:37:41 PM CEST Thorsten Leemhuis wrote:
> Hi! Find below my second regression report for Linux 4.14. It lists 8
> regressions I'm currently aware of. One regression was fixed since last
> weeks report. One was in there that shouldn't have been there.
>
> As always: Are
On Wed, 2017-09-20 at 10:19:51 UTC, Kamalesh Babulal wrote:
> While running stress test with livepatch module loaded, kernel
> bug was triggered.
...
>
> Signed-off-by: Kamalesh Babulal
> Cc: Balbir Singh
> Cc: Naveen N. Rao
> Cc: linuxppc-dev@lists.ozlabs.org
Applied to powerpc fixes, thanks.
On Thu, 2017-10-05 at 00:04:30 UTC, Thiago Jung Bauermann wrote:
> It turns out that not all paths calling arch_update_cpu_topology hold
> cpu_hotplug_lock, but that's ok because those paths aren't supposed to race
> with any concurrent hotplug events.
>
> Callers of arch_update_cpu_topology are e
On Tue, 2017-10-10 at 06:45:30 UTC, Sandipan Das wrote:
> According to the GCC documentation, the behaviour of __builtin_clz()
> and __builtin_clzl() is undefined if the value of the input argument
> is zero. Without handling this special case, these builtins have been
> used for emulating the foll
i2c-dev provides an interface for userspace programs to interact with I2C
devices, and is very helpful for I2C-related debugging.
Enable it in pseries_defconfig and powernv_defconfig. It's already enabled
in many other powerpc defconfigs.
Signed-off-by: Andrew Donnellan
---
arch/powerpc/configs
Bjorn Helgaas writes:
> On Fri, Sep 22, 2017 at 09:19:28AM -0500, Bryant G. Ly wrote:
>> This patch adds the machine dependent call for
>> pcibios_bus_add_device, since the previous patch
>> separated the calls out between the PowerNV and PowerVM.
>>
>> The difference here is that for the PowerV
Kamalesh Babulal writes:
> On Wednesday 11 October 2017 09:42 AM, Michael Ellerman wrote:
>> Kamalesh Babulal writes:
>>
>>> Use WARN_ON(), while running out of stubs in stub_for_addr()
>>> and abort loading of the module instead of BUG_ON().
>>
>> Thanks. This looks good in principle. Have yo
* Segher Boessenkool wrote (on 2017-10-11 17:02:16
+):
Hi Segher,
> Hi,
>
> On Wed, Oct 11, 2017 at 02:05:02PM +0530, Santosh Sivaraj wrote:
> > +70:ld r8,CFG_TB_UPDATE_COUNT(r3)
> > + andi. r0,r8,1 /* pending update ? loop */
> > + bne-70b
> > + xor
Use pr_fmt() in the watchdog code, so we don't have to say "Watchdog"
so many times.
Rather than "CPU:%d" just spell it "CPU %d", "Hard" doesn't need a
capital in the middle of a sentence, and "LOCKUP other CPUS" should be
"LOCKUP on other CPUS".
Also make it clear when a CPU self detects a locku
Currently when we take a TM Bad Thing program check exception, we
search the bug table to see if the program check was generated by a
WARN/WARN_ON etc.
That makes no sense, the WARN macros use trap instructions, which
should never generate a TM Bad Thing exception. If they ever did that
would be a
soft_nmi_interrupt() is called directly from the asm exception
handling code, which passes regs as a pointer to the stack. So regs
can't be NULL, it may be full of junk, but that's a separate problem.
Signed-off-by: Michael Ellerman
---
arch/powerpc/kernel/watchdog.c | 5 +
1 file changed, 1
When a CPU detects its locked up via soft_nmi_interrupt() we have
pt_regs, so print the regs->nip, which points to where we took the
soft-NMI.
Signed-off-by: Michael Ellerman
---
arch/powerpc/kernel/watchdog.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/powerpc/kerne
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