Pull timers and timekeeping updates from Thomas Gleixner:
- Core infrastucture work for Y2038 to address the COMPAT interfaces:
+ Add a new Y2038 safe __kernel_timespec and use it in the core
code
+ Introduce config switches which allow to control the various
compat mechanisms
+ Use the new config switch in the posix timer code to control the
32bit compat syscall implementation.
- Prevent bogus selection of CPU local clocksources which causes an
endless reselection loop
- Remove the extra kthread in the clocksource code which has no value
and just adds another level of indirection
- The usual bunch of trivial updates, cleanups and fixlets all over the
place
- More SPDX conversions
* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits)
clocksource/drivers/mxs_timer: Switch to SPDX identifier
clocksource/drivers/timer-imx-tpm: Switch to SPDX identifier
clocksource/drivers/timer-imx-gpt: Switch to SPDX identifier
clocksource/drivers/timer-imx-gpt: Remove outdated file path
clocksource/drivers/arc_timer: Add comments about locking while read GFRC
clocksource/drivers/mips-gic-timer: Add pr_fmt and reword pr_* messages
clocksource/drivers/sprd: Fix Kconfig dependency
clocksource: Move inline keyword to the beginning of function declarations
timer_list: Remove unused function pointer typedef
timers: Adjust a kernel-doc comment
tick: Prefer a lower rating device only if it's CPU local device
clocksource: Remove kthread
time: Change nanosleep to safe __kernel_* types
time: Change types to new y2038 safe __kernel_* types
time: Fix get_timespec64() for y2038 safe compat interfaces
time: Add new y2038 safe __kernel_timespec
posix-timers: Make compat syscalls depend on CONFIG_COMPAT_32BIT_TIME
time: Introduce CONFIG_COMPAT_32BIT_TIME
time: Introduce CONFIG_64BIT_TIME in architectures
compat: Enable compat_get/put_timespec64 always
...
Pull x86 cleanups from Ingo Molnar:
"Misc cleanups"
* 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/apm: Fix spelling mistake: "caculate" -> "calculate"
x86/mtrr: Rename main.c to mtrr.c and remove duplicate prefixes
x86: Remove pr_fmt duplicate logging prefixes
x86/early-quirks: Rename duplicate define of dev_err
x86/bpf: Clean up non-standard comments, to make the code more readable
Pull x86 boot updates from Ingo Molnar:
- Centaur CPU updates (David Wang)
- AMD and other CPU topology enumeration improvements and fixes
(Borislav Petkov, Thomas Gleixner, Suravee Suthikulpanit)
- Continued 5-level paging work (Kirill A. Shutemov)
* 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mm: Mark __pgtable_l5_enabled __initdata
x86/mm: Mark p4d_offset() __always_inline
x86/mm: Introduce the 'no5lvl' kernel parameter
x86/mm: Stop pretending pgtable_l5_enabled is a variable
x86/mm: Unify pgtable_l5_enabled usage in early boot code
x86/boot/compressed/64: Fix trampoline page table address calculation
x86/CPU: Move x86_cpuinfo::x86_max_cores assignment to detect_num_cpu_cores()
x86/Centaur: Report correct CPU/cache topology
x86/CPU: Move cpu_detect_cache_sizes() into init_intel_cacheinfo()
x86/CPU: Make intel_num_cpu_cores() generic
x86/CPU: Move cpu local function declarations to local header
x86/CPU/AMD: Derive CPU topology from CPUID function 0xB when available
x86/CPU: Modify detect_extended_topology() to return result
x86/CPU/AMD: Calculate last level cache ID from number of sharing threads
x86/CPU: Rename intel_cacheinfo.c to cacheinfo.c
perf/events/amd/uncore: Fix amd_uncore_llc ID to use pre-defined cpu_llc_id
x86/CPU/AMD: Have smp_num_siblings and cpu_llc_id always be present
x86/Centaur: Initialize supported CPU features properly
As of Skylake Server, there are a number of free running counters in
each IIO Box that collect counts of per-box IO clocks and per-port
Input/Output x BW/Utilization.
The free running counters cannot be part of the existing IIO BOX,
because, quoting from Peter Zijlstra:
"This will result in some (probably) unexpected scheduling artifacts.
Probably the only way to really cure that is to have the free running
counters in their own PMU and not share with the GP counters of this
box."
So let's add a new PMU for the free running counters, as suggested.
The free-running counter is read-only and always active. Counting will
be suspended only when the IIO Box is powered down.
There are three types of IIO free-running counters on Skylake server, IO
CLOCKS counter, BANDWIDTH counters and UTILIZATION counters.
IO CLOCKS counter is a clock of IIO box.
BANDWIDTH counters are to count inbound(PCIe->CPU)/outbound(CPU->PCIe)
bandwidth.
UTILIZATION counters are to count input/output utilization.
The bit width of the free-running counters is 36-bits.
Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Kan Liang <kan.liang@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: acme@kernel.org
Cc: eranian@google.com
Link: http://lkml.kernel.org/r/1525371913-10597-6-git-send-email-kan.liang@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
There are a number of free running counters introduced for uncore, which
provide highly valuable information to a wide array of customers.
However, the generic uncore code doesn't support them yet.
The free running counters will be specially handled based on their
unique attributes:
- They are read-only. They cannot be enabled/disabled.
- The event and the counter are always 1:1 mapped. It doesn't need to
be assigned nor tracked by event_list.
- They are always active. It doesn't need to check the availability.
- They have different bit width.
Also, using inline helpers to replace the check for fixed counter and
free running counter.
Signed-off-by: Kan Liang <kan.liang@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: acme@kernel.org
Cc: eranian@google.com
Link: http://lkml.kernel.org/r/1525371913-10597-5-git-send-email-kan.liang@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
There are a number of free running counters introduced for uncore, which
provide highly valuable information to a wide array of customers.
For example, Skylake Server has IIO free running counters to collect
Input/Output x BW/Utilization.
There is NO event available on the general purpose counters, that is
exactly the same as the free running counters. The generic uncore code
needs to be enhanced to support the new counters.
In the uncore document, there is no event-code assigned to free running
counters. Some events need to be defined to indicate the free running
counters. The events are encoded as event-code + umask-code.
The event-code for all free running counters is 0xff, which is the same
as the fixed counters:
- It has not been decided what code will be used for common events on
future platforms. 0xff is the only one which will definitely not be
used as any common event-code.
- Cannot re-use current events on the general purpose counters. Because
there is NO event available, that is exactly the same as the free
running counters.
- Even in the existing codes, the fixed counters for core, that have the
same event-code, may count different things. Hence, it should not
surprise the users if the free running counters that share the same
event-code also count different things.
Umask will be used to distinguish the counters.
The umask-code is used to distinguish a fixed counter and a free running
counter, and different types of free running counters.
For fixed counters, the umask-code is 0x0X, where X indicates the index
of the fixed counter, which starts from 0.
- Compatible with the old event encoding.
- Currently, there is only one fixed counter. There are still 15
reserved spaces for extension.
For free running counters, the umask-code uses the rest of the space.
It would follow the format of 0xXY:
- X stands for the type of free running counters, which starts from 1.
- Y stands for the index of free running counters of same type, which
starts from 0.
- The free running counters do different thing. It can be categorized to
several types, according to the MSR location, bit width and
definition. E.g. there are three types of IIO free running counters on
Skylake server to monitor IO CLOCKS, BANDWIDTH and UTILIZATION on
different ports. It makes it easy to locate the free running counter
of a specific type.
- So far, there are at most 8 counters of each type. There are still 8
reserved spaces for extension.
Introducing a new index to indicate the free running counters. Only one
index is enough for all free running counters. Because the free running
counters are always active, and the event and free running counter are
always 1:1 mapped, it does not need extra index to indicate the assigned
counter.
Introducing a new data structure to store free running counters related
information for each type. It includes the number of counters, bit
width, base address, offset between counters and offset between boxes.
Introducing several inline helpers to check index for fixed counter and
free running counter, validate free running counter event, and retrieve
the free running counter information according to box and event.
Signed-off-by: Kan Liang <kan.liang@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: acme@kernel.org
Cc: eranian@google.com
Link: http://lkml.kernel.org/r/1525371913-10597-4-git-send-email-kan.liang@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
There are two free-running counters for client IMC uncore. The
customized event_init() function hard codes their index to
'UNCORE_PMC_IDX_FIXED' and 'UNCORE_PMC_IDX_FIXED + 1'.
To support the index 'UNCORE_PMC_IDX_FIXED + 1', the generic
uncore_perf_event_update is obscurely hacked.
The code quality issue will bring problems when a new counter index is
introduced into the generic code, for example, a new index for
free-running counter.
Introducing a customized event_read() function for client IMC uncore.
The customized function is copied from previous generic
uncore_pmu_event_read().
The index 'UNCORE_PMC_IDX_FIXED + 1' will be isolated for client IMC
uncore only.
Signed-off-by: Kan Liang <kan.liang@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: acme@kernel.org
Cc: eranian@google.com
Link: http://lkml.kernel.org/r/1525371913-10597-1-git-send-email-kan.liang@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The SMM freeze feature was introduced since PerfMon V2. But the current
code unconditionally enables the feature for all platforms. It can
generate #GP exception, if the related FREEZE_WHILE_SMM bit is set for
the machine with PerfMon V1.
To disable the feature for PerfMon V1, perf needs to
- Remove the freeze_on_smi sysfs entry by moving intel_pmu_attrs to
intel_pmu, which is only applied to PerfMon V2 and later.
- Check the PerfMon version before flipping the SMM bit when starting CPU
Fixes: 6089327f54 ("perf/x86: Add sysfs entry to freeze counters on SMI")
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: ak@linux.intel.com
Cc: eranian@google.com
Cc: acme@redhat.com
Link: https://lkml.kernel.org/r/1524682637-63219-1-git-send-email-kan.liang@linux.intel.com
This patch removes a redundant store on regs->flags introduced
by commit:
71eb9ee959 ("perf/x86/intel: Fix linear IP of PEBS real_ip on Haswell and later CPUs")
We were clearing the PERF_EFLAGS_EXACT but it was overwritten by
regs->flags = pebs->flags later on.
The PERF_EFLAGS_EXACT is a software flag using bit 3 of regs->flags.
X86 marks this bit as Reserved. To make sure this bit is zero before
we do any IP processing, we clear it explicitly.
Patch also removes the following assignment:
regs->flags = pebs->flags | (regs->flags & PERF_EFLAGS_VM);
Because there is no regs->flags to preserve anymore because
set_linear_ip() is not called until later.
Signed-off-by: Stephane Eranian <eranian@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: kan.liang@intel.com
Link: http://lkml.kernel.org/r/1522909791-32498-1-git-send-email-eranian@google.com
[ Improve capitalization, punctuation and clarity of comments. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull x86 timer updates from Ingo Molnar:
"Two changes: add the new convert_art_ns_to_tsc() API for upcoming
Intel Goldmont+ drivers, and remove the obsolete rdtscll() API"
* 'x86-timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/tsc: Get rid of rdtscll()
x86/tsc: Convert ART in nanoseconds to TSC
this patch fix a bug in how the pebs->real_ip is handled in the PEBS
handler. real_ip only exists in Haswell and later processor. It is
actually the eventing IP, i.e., where the event occurred. As opposed
to the pebs->ip which is the PEBS interrupt IP which is always off
by one.
The problem is that the real_ip just like the IP needs to be fixed up
because PEBS does not record all the machine state registers, and
in particular the code segement (cs). This is why we have the set_linear_ip()
function. The problem was that set_linear_ip() was only used on the pebs->ip
and not the pebs->real_ip.
We have profiles which ran into invalid callstacks because of this.
Here is an example:
..... 0: ffffffffffffff80 recent entry, marker kernel v
..... 1: 000000000040044d <= user address in kernel space!
..... 2: fffffffffffffe00 marker enter user v
..... 3: 000000000040044d
..... 4: 00000000004004b6 oldest entry
Debugging output in get_perf_callchain():
[ 857.769909] CALLCHAIN: CPU8 ip=40044d regs->cs=10 user_mode(regs)=0
The problem is that the kernel entry in 1: points to a user level
address. How can that be?
The reason is that with PEBS sampling the instruction that caused the event
to occur and the instruction where the CPU was when the interrupt was posted
may be far apart. And sometime during that time window, the privilege level may
change. This happens, for instance, when the PEBS sample is taken close to a
kernel entry point. Here PEBS, eventing IP (real_ip) captured a user level
instruction. But by the time the PMU interrupt fired, the processor had already
entered kernel space. This is why the debug output shows a user address with
user_mode() false.
The problem comes from PEBS not recording the code segment (cs) register.
The register is used in x86_64 to determine if executing in kernel vs user
space. This is okay because the kernel has a software workaround called
set_linear_ip(). But the issue in setup_pebs_sample_data() is that
set_linear_ip() is never called on the real_ip value when it is available
(Haswell and later) and precise_ip > 1.
This patch fixes this problem and eliminates the callchain discrepancy.
The patch restructures the code around set_linear_ip() to minimize the number
of times the IP has to be set.
Signed-off-by: Stephane Eranian <eranian@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: kan.liang@intel.com
Link: http://lkml.kernel.org/r/1521788507-10231-1-git-send-email-eranian@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
With the cherry-picked perf/urgent commit merged separately we can now
merge all the fixes without conflicts.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Commit 99770737ca ("x86/asm/tsc: Add rdtscll() merge helper") added
rdtscll() in August 2015 along with the comment:
/* Deprecated, keep it for a cycle for easier merging: */
12 cycles later it's really overdue for removal.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
There is a bug when reading event->count with large PEBS enabled.
Here is an example:
# ./read_count
0x71f0
0x122c0
0x1000000001c54
0x100000001257d
0x200000000bdc5
In fixed period mode, the auto-reload mechanism could be enabled for
PEBS events, but the calculation of event->count does not take the
auto-reload values into account.
Anyone who reads event->count will get the wrong result, e.g x86_pmu_read().
This bug was introduced with the auto-reload mechanism enabled since
commit:
851559e35f ("perf/x86/intel: Use the PEBS auto reload mechanism when possible")
Introduce intel_pmu_save_and_restart_reload() to calculate the
event->count only for auto-reload.
Since the counter increments a negative counter value and overflows on
the sign switch, giving the interval:
[-period, 0]
the difference between two consequtive reads is:
A) value2 - value1;
when no overflows have happened in between,
B) (0 - value1) + (value2 - (-period));
when one overflow happened in between,
C) (0 - value1) + (n - 1) * (period) + (value2 - (-period));
when @n overflows happened in between.
Here A) is the obvious difference, B) is the extension to the discrete
interval, where the first term is to the top of the interval and the
second term is from the bottom of the next interval and C) the extension
to multiple intervals, where the middle term is the whole intervals
covered.
The equation for all cases is:
value2 - value1 + n * period
Previously the event->count is updated right before the sample output.
But for case A, there is no PEBS record ready. It needs to be specially
handled.
Remove the auto-reload code from x86_perf_event_set_period() since
we'll not longer call that function in this case.
Based-on-code-from: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: acme@kernel.org
Fixes: 851559e35f ("perf/x86/intel: Use the PEBS auto reload mechanism when possible")
Link: http://lkml.kernel.org/r/1518474035-21006-2-git-send-email-kan.liang@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>