<feed xmlns='http://www.w3.org/2005/Atom'>
<title>user/sven/linux.git/drivers/perf, branch v6.5.9</title>
<subtitle>Linux Kernel
</subtitle>
<id>https://git.stealer.net/cgit.cgi/user/sven/linux.git/atom?h=v6.5.9</id>
<link rel='self' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/atom?h=v6.5.9'/>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/'/>
<updated>2023-10-19T21:10:55Z</updated>
<entry>
<title>perf/arm-cmn: Fix the unhandled overflow status of counter 4 to 7</title>
<updated>2023-10-19T21:10:55Z</updated>
<author>
<name>Jing Zhang</name>
<email>renyu.zj@linux.alibaba.com</email>
</author>
<published>2023-09-25T03:22:32Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=1cd61412f98df5e73e8c6101b5d62988041c41ac'/>
<id>urn:sha1:1cd61412f98df5e73e8c6101b5d62988041c41ac</id>
<content type='text'>
[ Upstream commit 7f949f6f54ff593123ab95b6247bfa4542a65580 ]

The register por_dt_pmovsr Bits[7:0] indicates overflow from counters 7
to 0. But in arm_cmn_handle_irq(), only handled the overflow status of
Bits[3:0] which results in unhandled overflow status of counters 4 to 7.

So let the overflow status of DTC counters 4 to 7 to be handled.

Fixes: 0ba64770a2f2 ("perf: Add Arm CMN-600 PMU driver")
Signed-off-by: Jing Zhang &lt;renyu.zj@linux.alibaba.com&gt;
Reviewed-by: Robin Murphy &lt;robin.murphy@arm.com&gt;
Link: https://lore.kernel.org/r/1695612152-123633-1-git-send-email-renyu.zj@linux.alibaba.com
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>perf/imx_ddr: speed up overflow frequency of cycle</title>
<updated>2023-09-23T09:14:18Z</updated>
<author>
<name>Xu Yang</name>
<email>xu.yang_2@nxp.com</email>
</author>
<published>2023-08-11T01:54:37Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=e5c68fbd4c6628c81a83916f282aebc52065ef1f'/>
<id>urn:sha1:e5c68fbd4c6628c81a83916f282aebc52065ef1f</id>
<content type='text'>
[ Upstream commit e89ecd8368860bf05437eabd07d292c316221cfc ]

For i.MX8MP, we cannot ensure that cycle counter overflow occurs at least
4 times as often as other events. Due to byte counters will count for any
event configured, it will overflow more often. And if byte counters
overflow that related counters would stop since they share the
COUNTER_CNTL. We can speed up cycle counter overflow frequency by setting
counter parameter (CP) field of cycle counter. In this way, we can avoid
stop counting byte counters when interrupt didn't come and the byte
counters can be fetched or updated from each cycle counter overflow
interrupt.

Because we initialize CP filed to shorten counter0 overflow time, the cycle
counter will start couting from a fixed/base value each time. We need to
remove the base from the result too. Therefore, we could get precise result
from cycle counter.

Signed-off-by: Xu Yang &lt;xu.yang_2@nxp.com&gt;
Reviewed-by: Frank Li &lt;Frank.Li@nxp.com&gt;
Link: https://lore.kernel.org/r/20230811015438.1999307-1-xu.yang_2@nxp.com
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>perf/smmuv3: Enable HiSilicon Erratum 162001900 quirk for HIP08/09</title>
<updated>2023-09-23T09:14:18Z</updated>
<author>
<name>Yicong Yang</name>
<email>yangyicong@hisilicon.com</email>
</author>
<published>2023-08-14T12:40:12Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=cf5882b610563372f06aa2f57648e2fb4e896970'/>
<id>urn:sha1:cf5882b610563372f06aa2f57648e2fb4e896970</id>
<content type='text'>
[ Upstream commit 0242737dc4eb9f6e9a5ea594b3f93efa0b12f28d ]

Some HiSilicon SMMU PMCG suffers the erratum 162001900 that the PMU
disable control sometimes fail to disable the counters. This will lead
to error or inaccurate data since before we enable the counters the
counter's still counting for the event used in last perf session.

This patch tries to fix this by hardening the global disable process.
Before disable the PMU, writing an invalid event type (0xffff) to
focibly stop the counters. Correspondingly restore each events on
pmu::pmu_enable().

Signed-off-by: Yicong Yang &lt;yangyicong@hisilicon.com&gt;
Link: https://lore.kernel.org/r/20230814124012.58013-1-yangyicong@huawei.com
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>perf/imx_ddr: don't enable counter0 if none of 4 counters are used</title>
<updated>2023-09-13T07:53:00Z</updated>
<author>
<name>Xu Yang</name>
<email>xu.yang_2@nxp.com</email>
</author>
<published>2023-08-11T01:54:38Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=5b9836417c99081de40bf76c23cd229b7a001527'/>
<id>urn:sha1:5b9836417c99081de40bf76c23cd229b7a001527</id>
<content type='text'>
[ Upstream commit f4e2bd91ddf5e8543cbe7ad80b3fba3d2dc63fa3 ]

In current driver, counter0 will be enabled after ddr_perf_pmu_enable()
is called even though none of the 4 counters are used. This will cause
counter0 continue to count until ddr_perf_pmu_disabled() is called. If
pmu is not disabled all the time, the pmu interrupt will be asserted
from time to time due to counter0 will overflow and irq handler will
clear it. It's not an expected behavior. This patch will not enable
counter0 if none of 4 counters are used.

Fixes: 9a66d36cc7ac ("drivers/perf: imx_ddr: Add DDR performance counter support to perf")
Signed-off-by: Xu Yang &lt;xu.yang_2@nxp.com&gt;
Reviewed-by: Frank Li &lt;Frank.Li@nxp.com&gt;
Link: https://lore.kernel.org/r/20230811015438.1999307-2-xu.yang_2@nxp.com
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>perf: RISC-V: Remove PERF_HES_STOPPED flag checking in riscv_pmu_start()</title>
<updated>2023-07-12T14:41:23Z</updated>
<author>
<name>Eric Lin</name>
<email>eric.lin@sifive.com</email>
</author>
<published>2023-07-10T15:43:28Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=66843b14fb71825fdd73ab12f6594f2243b402be'/>
<id>urn:sha1:66843b14fb71825fdd73ab12f6594f2243b402be</id>
<content type='text'>
Since commit 096b52fd2bb4 ("perf: RISC-V: throttle perf events") the
perf_sample_event_took() function was added to report time spent in
overflow interrupts. If the interrupt takes too long, the perf framework
will lower the sysctl_perf_event_sample_rate and max_samples_per_tick.
When hwc-&gt;interrupts is larger than max_samples_per_tick, the
hwc-&gt;interrupts will be set to MAX_INTERRUPTS, and events will be
throttled within the __perf_event_account_interrupt() function.

However, the RISC-V PMU driver doesn't call riscv_pmu_stop() to update the
PERF_HES_STOPPED flag after perf_event_overflow() in pmu_sbi_ovf_handler()
function to avoid throttling. When the perf framework unthrottled the event
in the timer interrupt handler, it triggers riscv_pmu_start() function
and causes a WARN_ON_ONCE() warning, as shown below:

 ------------[ cut here ]------------
 WARNING: CPU: 0 PID: 240 at drivers/perf/riscv_pmu.c:184 riscv_pmu_start+0x7c/0x8e
 Modules linked in:
 CPU: 0 PID: 240 Comm: ls Not tainted 6.4-rc4-g19d0788e9ef2 #1
 Hardware name: SiFive (DT)
 epc : riscv_pmu_start+0x7c/0x8e
  ra : riscv_pmu_start+0x28/0x8e
 epc : ffffffff80aef864 ra : ffffffff80aef810 sp : ffff8f80004db6f0
  gp : ffffffff81c83750 tp : ffffaf80069f9bc0 t0 : ffff8f80004db6c0
  t1 : 0000000000000000 t2 : 000000000000001f s0 : ffff8f80004db720
  s1 : ffffaf8008ca1068 a0 : 0000ffffffffffff a1 : 0000000000000000
  a2 : 0000000000000001 a3 : 0000000000000870 a4 : 0000000000000000
  a5 : 0000000000000000 a6 : 0000000000000840 a7 : 0000000000000030
  s2 : 0000000000000000 s3 : ffffaf8005165800 s4 : ffffaf800424da00
  s5 : ffffffffffffffff s6 : ffffffff81cc7590 s7 : 0000000000000000
  s8 : 0000000000000006 s9 : 0000000000000001 s10: ffffaf807efbc340
  s11: ffffaf807efbbf00 t3 : ffffaf8006a16028 t4 : 00000000dbfbb796
  t5 : 0000000700000000 t6 : ffffaf8005269870
 status: 0000000200000100 badaddr: 0000000000000000 cause: 0000000000000003
 [&lt;ffffffff80aef864&gt;] riscv_pmu_start+0x7c/0x8e
 [&lt;ffffffff80185b56&gt;] perf_adjust_freq_unthr_context+0x15e/0x174
 [&lt;ffffffff80188642&gt;] perf_event_task_tick+0x88/0x9c
 [&lt;ffffffff800626a8&gt;] scheduler_tick+0xfe/0x27c
 [&lt;ffffffff800b5640&gt;] update_process_times+0x9a/0xba
 [&lt;ffffffff800c5bd4&gt;] tick_sched_handle+0x32/0x66
 [&lt;ffffffff800c5e0c&gt;] tick_sched_timer+0x64/0xb0
 [&lt;ffffffff800b5e50&gt;] __hrtimer_run_queues+0x156/0x2f4
 [&lt;ffffffff800b6bdc&gt;] hrtimer_interrupt+0xe2/0x1fe
 [&lt;ffffffff80acc9e8&gt;] riscv_timer_interrupt+0x38/0x42
 [&lt;ffffffff80090a16&gt;] handle_percpu_devid_irq+0x90/0x1d2
 [&lt;ffffffff8008a9f4&gt;] generic_handle_domain_irq+0x28/0x36

After referring other PMU drivers like Arm, Loongarch, Csky, and Mips,
they don't call *_pmu_stop() to update with PERF_HES_STOPPED flag
after perf_event_overflow() function nor do they add PERF_HES_STOPPED
flag checking in *_pmu_start() which don't cause this warning.

Thus, it's recommended to remove this unnecessary check in
riscv_pmu_start() function to prevent this warning.

Signed-off-by: Eric Lin &lt;eric.lin@sifive.com&gt;
Link: https://lore.kernel.org/r/20230710154328.19574-1-eric.lin@sifive.com
Fixes: 096b52fd2bb4 ("perf: RISC-V: throttle perf events")
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt &lt;palmer@rivosinc.com&gt;
</content>
</entry>
<entry>
<title>Merge tag 'cxl-for-6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl</title>
<updated>2023-07-01T15:58:41Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2023-07-01T15:58:41Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=d25f002575146d67b5ebea541e6db3696c957c25'/>
<id>urn:sha1:d25f002575146d67b5ebea541e6db3696c957c25</id>
<content type='text'>
Pull CXL updates from Dan Williams:
 "The highlights in terms of new functionality are support for the
  standard CXL Performance Monitor definition that appeared in CXL 3.0,
  support for device sanitization (wiping all data from a device),
  secure-erase (re-keying encryption of user data), and support for
  firmware update. The firmware update support is notable as it reuses
  the simple sysfs_upload interface to just cat(1) a blob to a sysfs
  file and pipe that to the device.

  Additionally there are a substantial number of cleanups and
  reorganizations to get ready for RCH error handling (RCH == Restricted
  CXL Host == current shipping hardware generation / pre CXL-2.0
  topologies) and type-2 (accelerator / vendor specific) devices.

  For vendor specific devices they implement a subset of what the
  generic type-3 (generic memory expander) driver expects. As a result
  the rework decouples optional infrastructure from the core driver
  context.

  For RCH topologies, where the specification working group did not want
  to confuse pre-CXL-aware operating systems, many of the standard
  registers are hidden which makes support standard bus features like
  AER (PCIe Advanced Error Reporting) difficult. The rework arranges for
  the driver to help the PCI-AER core. Bjorn is on board with this
  direction but a late regression disocvery means the completion of this
  functionality needs to cook a bit longer, so it is code
  reorganizations only for now.

  Summary:

   - Add infrastructure for supporting background commands along with
     support for device sanitization and firmware update

   - Introduce a CXL performance monitoring unit driver based on the
     common definition in the specification.

   - Land some preparatory cleanup and refactoring for the anticipated
     arrival of CXL type-2 (accelerator devices) and CXL RCH (CXL-v1.1
     topology) error handling.

   - Rework CPU cache management with respect to region configuration
     (device hotplug or other dynamic changes to memory interleaving)

   - Fix region reconfiguration vs CXL decoder ordering rules"

* tag 'cxl-for-6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl: (51 commits)
  cxl: Fix one kernel-doc comment
  cxl/pci: Use correct flag for sanitize polling
  docs: perf: Minimal introduction the the CXL PMU device and driver
  perf: CXL Performance Monitoring Unit driver
  tools/testing/cxl: add firmware update emulation to CXL memdevs
  tools/testing/cxl: Use named effects for the Command Effect Log
  tools/testing/cxl: Fix command effects for inject/clear poison
  cxl: add a firmware update mechanism using the sysfs firmware loader
  cxl/test: Add Secure Erase opcode support
  cxl/mem: Support Secure Erase
  cxl/test: Add Sanitize opcode support
  cxl/mem: Wire up Sanitization support
  cxl/mbox: Add sanitization handling machinery
  cxl/mem: Introduce security state sysfs file
  cxl/mbox: Allow for IRQ_NONE case in the isr
  Revert "cxl/port: Enable the HDM decoder capability for switch ports"
  cxl/memdev: Formalize endpoint port linkage
  cxl/pci: Unconditionally unmask 256B Flit errors
  cxl/region: Manage decoder target_type at decoder-attach time
  cxl/hdm: Default CXL_DEVTYPE_DEVMEM decoders to CXL_DECODER_DEVMEM
  ...
</content>
</entry>
<entry>
<title>Merge tag 'riscv-for-linus-6.5-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux</title>
<updated>2023-06-30T16:37:26Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2023-06-30T16:37:26Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=533925cb760431cb496a8c965cfd765a1a21d37e'/>
<id>urn:sha1:533925cb760431cb496a8c965cfd765a1a21d37e</id>
<content type='text'>
Pull RISC-V updates from Palmer Dabbelt:

 - Support for ACPI

 - Various cleanups to the ISA string parsing, including making them
   case-insensitive

 - Support for the vector extension

 - Support for independent irq/softirq stacks

 - Our CPU DT binding now has "unevaluatedProperties: false"

* tag 'riscv-for-linus-6.5-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (78 commits)
  riscv: hibernate: remove WARN_ON in save_processor_state
  dt-bindings: riscv: cpus: switch to unevaluatedProperties: false
  dt-bindings: riscv: cpus: add a ref the common cpu schema
  riscv: stack: Add config of thread stack size
  riscv: stack: Support HAVE_SOFTIRQ_ON_OWN_STACK
  riscv: stack: Support HAVE_IRQ_EXIT_ON_IRQ_STACK
  RISC-V: always report presence of extensions formerly part of the base ISA
  dt-bindings: riscv: explicitly mention assumption of Zicntr &amp; Zihpm support
  RISC-V: remove decrement/increment dance in ISA string parser
  RISC-V: rework comments in ISA string parser
  RISC-V: validate riscv,isa at boot, not during ISA string parsing
  RISC-V: split early &amp; late of_node to hartid mapping
  RISC-V: simplify register width check in ISA string parsing
  perf: RISC-V: Limit the number of counters returned from SBI
  riscv: replace deprecated scall with ecall
  riscv: uprobes: Restore thread.bad_cause
  riscv: mm: try VMA lock-based page fault handling first
  riscv: mm: Pre-allocate PGD entries for vmalloc/modules area
  RISC-V: hwprobe: Expose Zba, Zbb, and Zbs
  RISC-V: Track ISA extensions per hart
  ...
</content>
</entry>
<entry>
<title>Merge tag 'mm-nonmm-stable-2023-06-24-19-23' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm</title>
<updated>2023-06-28T17:59:38Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2023-06-28T17:59:38Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=77b1a7f7a05c673c187894b4ae898a8c0cdc776c'/>
<id>urn:sha1:77b1a7f7a05c673c187894b4ae898a8c0cdc776c</id>
<content type='text'>
Pull non-mm updates from Andrew Morton:

 - Arnd Bergmann has fixed a bunch of -Wmissing-prototypes in top-level
   directories

 - Douglas Anderson has added a new "buddy" mode to the hardlockup
   detector. It permits the detector to work on architectures which
   cannot provide the required interrupts, by having CPUs periodically
   perform checks on other CPUs

 - Zhen Lei has enhanced kexec's ability to support two crash regions

 - Petr Mladek has done a lot of cleanup on the hard lockup detector's
   Kconfig entries

 - And the usual bunch of singleton patches in various places

* tag 'mm-nonmm-stable-2023-06-24-19-23' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (72 commits)
  kernel/time/posix-stubs.c: remove duplicated include
  ocfs2: remove redundant assignment to variable bit_off
  watchdog/hardlockup: fix typo in config HARDLOCKUP_DETECTOR_PREFER_BUDDY
  powerpc: move arch_trigger_cpumask_backtrace from nmi.h to irq.h
  devres: show which resource was invalid in __devm_ioremap_resource()
  watchdog/hardlockup: define HARDLOCKUP_DETECTOR_ARCH
  watchdog/sparc64: define HARDLOCKUP_DETECTOR_SPARC64
  watchdog/hardlockup: make HAVE_NMI_WATCHDOG sparc64-specific
  watchdog/hardlockup: declare arch_touch_nmi_watchdog() only in linux/nmi.h
  watchdog/hardlockup: make the config checks more straightforward
  watchdog/hardlockup: sort hardlockup detector related config values a logical way
  watchdog/hardlockup: move SMP barriers from common code to buddy code
  watchdog/buddy: simplify the dependency for HARDLOCKUP_DETECTOR_PREFER_BUDDY
  watchdog/buddy: don't copy the cpumask in watchdog_next_cpu()
  watchdog/buddy: cleanup how watchdog_buddy_check_hardlockup() is called
  watchdog/hardlockup: remove softlockup comment in touch_nmi_watchdog()
  watchdog/hardlockup: in watchdog_hardlockup_check() use cpumask_copy()
  watchdog/hardlockup: don't use raw_cpu_ptr() in watchdog_hardlockup_kick()
  watchdog/hardlockup: HAVE_NMI_WATCHDOG must implement watchdog_hardlockup_probe()
  watchdog/hardlockup: keep kernel.nmi_watchdog sysctl as 0444 if probe fails
  ...
</content>
</entry>
<entry>
<title>Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux</title>
<updated>2023-06-27T00:11:53Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2023-06-27T00:11:53Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=2605e80d3438c77190f55b821c6575048c68268e'/>
<id>urn:sha1:2605e80d3438c77190f55b821c6575048c68268e</id>
<content type='text'>
Pull arm64 updates from Catalin Marinas:
 "Notable features are user-space support for the memcpy/memset
  instructions and the permission indirection extension.

   - Support for the Armv8.9 Permission Indirection Extensions. While
     this feature doesn't add new functionality, it enables future
     support for Guarded Control Stacks (GCS) and Permission Overlays

   - User-space support for the Armv8.8 memcpy/memset instructions

   - arm64 perf: support the HiSilicon SoC uncore PMU, Arm CMN sysfs
     identifier, support for the NXP i.MX9 SoC DDRC PMU, fixes and
     cleanups

   - Removal of superfluous ISBs on context switch (following
     retrospective architecture tightening)

   - Decode the ISS2 register during faults for additional information
     to help with debugging

   - KPTI clean-up/simplification of the trampoline exit code

   - Addressing several -Wmissing-prototype warnings

   - Kselftest improvements for signal handling and ptrace

   - Fix TPIDR2_EL0 restoring on sigreturn

   - Clean-up, robustness improvements of the module allocation code

   - More sysreg conversions to the automatic register/bitfields
     generation

   - CPU capabilities handling cleanup

   - Arm documentation updates: ACPI, ptdump"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (124 commits)
  kselftest/arm64: Add a test case for TPIDR2 restore
  arm64/signal: Restore TPIDR2 register rather than memory state
  arm64: alternatives: make clean_dcache_range_nopatch() noinstr-safe
  Documentation/arm64: Add ptdump documentation
  arm64: hibernate: remove WARN_ON in save_processor_state
  kselftest/arm64: Log signal code and address for unexpected signals
  docs: perf: Fix warning from 'make htmldocs' in hisi-pmu.rst
  arm64/fpsimd: Exit streaming mode when flushing tasks
  docs: perf: Add new description for HiSilicon UC PMU
  drivers/perf: hisi: Add support for HiSilicon UC PMU driver
  drivers/perf: hisi: Add support for HiSilicon H60PA and PAv3 PMU driver
  perf: arm_cspmu: Add missing MODULE_DEVICE_TABLE
  perf/arm-cmn: Add sysfs identifier
  perf/arm-cmn: Revamp model detection
  perf/arm_dmc620: Add cpumask
  arm64: mm: fix VA-range sanity check
  arm64/mm: remove now-superfluous ISBs from TTBR writes
  Documentation/arm64: Update ACPI tables from BBR
  Documentation/arm64: Update references in arm-acpi
  Documentation/arm64: Update ARM and arch reference
  ...
</content>
</entry>
<entry>
<title>perf: CXL Performance Monitoring Unit driver</title>
<updated>2023-06-26T00:47:09Z</updated>
<author>
<name>Jonathan Cameron</name>
<email>Jonathan.Cameron@huawei.com</email>
</author>
<published>2023-05-26T09:58:23Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=5d7107c72796df3be2ba574f1cf6eca75c60d5ef'/>
<id>urn:sha1:5d7107c72796df3be2ba574f1cf6eca75c60d5ef</id>
<content type='text'>
CXL rev 3.0 introduces a standard performance monitoring hardware
block to CXL. Instances are discovered using CXL Register Locator DVSEC
entries. Each CXL component may have multiple PMUs.

This initial driver supports a subset of types of counter.
It supports counters that are either fixed or configurable, but requires
that they support the ability to freeze and write value whilst frozen.

Development done with QEMU model which will be posted shortly.

Example:

$ perf stat -a -e cxl_pmu_mem0.0/h2d_req_snpcur/ -e cxl_pmu_mem0.0/h2d_req_snpdata/ -e cxl_pmu_mem0.0/clock_ticks/ sleep 1

Performance counter stats for 'system wide':

96,757,023,244,321      cxl_pmu_mem0.0/h2d_req_snpcur/
96,757,023,244,365      cxl_pmu_mem0.0/h2d_req_snpdata/
193,514,046,488,653      cxl_pmu_mem0.0/clock_ticks/

       1.090539600 seconds time elapsed

Reviewed-by: Dave Jiang &lt;dave.jiang@intel.com&gt;
Reviewed-by: Kan Liang &lt;kan.liang@linux.intel.com&gt;
Signed-off-by: Jonathan Cameron &lt;Jonathan.Cameron@huawei.com&gt;
Link: https://lore.kernel.org/r/20230526095824.16336-5-Jonathan.Cameron@huawei.com
Signed-off-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
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