Hi,
In /proc/PID/stat, there is the kstkesp field which is the stack pointer of
a thread. While the thread is active, this field reads zero. But during a
coredump, it should have a valid value.
However, at the moment, kstkesp is zero even during coredump.
The first commit fixes this problem, and the second commit adds a selftest
to detect if this problem appears again in the future.
Nam Cao (2):
fs/proc: do_task_stat: Fix ESP not readable during coredump
selftests: coredump: Add stackdump test
fs/proc/array.c | 36 ++--
tools/testing/selftests/coredump/Makefile | 7 +
tools/testing/selftests/coredump/README.rst | 50 ++++++
tools/testing/selftests/coredump/stackdump | 14 ++
.../selftests/coredump/stackdump_test.c | 154 ++++++++++++++++++
5 files changed, 243 insertions(+), 18 deletions(-)
create mode 100644 tools/testing/selftests/coredump/Makefile
create mode 100644 tools/testing/selftests/coredump/README.rst
create mode 100755 tools/testing/selftests/coredump/stackdump
create mode 100644 tools/testing/selftests/coredump/stackdump_test.c
--
2.39.5
This series was prompted by feedback given in [1].
Patch 1 : Adds safe_hlt() and cli() helpers.
Patch 2, 3: Adds an interface to read vcpu stat in selftest. Adds
a macro to generate compiler error to detect typos at
compile time while parsing vcpu and vm stats.
Patch 4 : Fix few of the selftests based on newly defined macro.
This series was split from the Idle HLT intercept support series [2]
because the series has a few changes in the vm_get_stat() interface
as suggested in [1] and a few changes in two of the self-tests
(nx_huge_pages_test.c and dirty_log_page_splitting_test.c) which use
vm_get_stat() functionality to retrieve specified VM stats. These
changes are unrelated to the Idle HLT intercept support series [2].
[1] https://lore.kernel.org/kvm/ZruDweYzQRRcJeTO@google.com/T/#m7cd7a110f0fcff9…
[2] https://lore.kernel.org/kvm/ZruDweYzQRRcJeTO@google.com/T/#m6c67ca8ccb226e5…
Manali Shukla (4):
KVM: selftests: Add safe_halt() and cli() helpers to common code
KVM: selftests: Add an interface to read the data of named vcpu stat
KVM: selftests: convert vm_get_stat to macro
KVM: selftests: Replace previously used vm_get_stat() to macro
.../testing/selftests/kvm/include/kvm_util.h | 83 +++++++++++++++++--
.../kvm/include/x86_64/kvm_util_arch.h | 52 ++++++++++++
.../selftests/kvm/include/x86_64/processor.h | 17 ++++
tools/testing/selftests/kvm/lib/kvm_util.c | 40 +++++++++
.../x86_64/dirty_log_page_splitting_test.c | 6 +-
.../selftests/kvm/x86_64/nx_huge_pages_test.c | 4 +-
6 files changed, 191 insertions(+), 11 deletions(-)
base-commit: c8d430db8eec7d4fd13a6bea27b7086a54eda6da
--
2.34.1
Since commit e87412e621f1 ("integrate Zaamo and Zalrsc text (#1304)"),
the A extension has been described as a set of instructions provided by
Zaamo and Zalrsc. Add these two extensions.
This series is based on the Zc one [1].
Link: https://lore.kernel.org/linux-riscv/20240619113529.676940-1-cleger@rivosinc…
---
Clément Léger (5):
dt-bindings: riscv: add Zaamo and Zalrsc ISA extension description
riscv: add parsing for Zaamo and Zalrsc extensions
riscv: hwprobe: export Zaamo and Zalrsc extensions
RISC-V: KVM: Allow Zaamo/Zalrsc extensions for Guest/VM
KVM: riscv: selftests: Add Zaamo/Zalrsc extensions to get-reg-list
test
Documentation/arch/riscv/hwprobe.rst | 8 ++++++++
.../devicetree/bindings/riscv/extensions.yaml | 19 +++++++++++++++++++
arch/riscv/include/asm/hwcap.h | 2 ++
arch/riscv/include/uapi/asm/hwprobe.h | 2 ++
arch/riscv/include/uapi/asm/kvm.h | 2 ++
arch/riscv/kernel/cpufeature.c | 9 ++++++++-
arch/riscv/kernel/sys_hwprobe.c | 2 ++
arch/riscv/kvm/vcpu_onereg.c | 4 ++++
.../selftests/kvm/riscv/get-reg-list.c | 8 ++++++++
9 files changed, 55 insertions(+), 1 deletion(-)
--
2.45.2
Currently, the situation when guest accesses MMIO during vectoring is
handled differently on VMX and SVM: on VMX KVM returns internal error,
when SVM goes into infinite loop trying to deliver an event again and
again.
This patch series eliminates this difference by returning a KVM internal
error when guest performs MMIO during vectoring for both VMX and SVM.
Also, introduce a selftest test case which covers the error handling
mentioned above.
V1 -> V2:
- Make commit messages more brief, avoid using pronouns
- Extract SVM error handling into a separate commit
- Introduce a new X86EMUL_ return type and detect the unhandleable
vectoring error in vendor-specific check_emulate_instruction instead of
handling it in the common MMU code (which is specific for cached MMIO)
Ivan Orlov (6):
KVM: x86: Add function for vectoring error generation
KVM: x86: Add emulation status for vectoring during MMIO
KVM: VMX: Handle vectoring error in check_emulate_instruction
KVM: SVM: Handle MMIO during vectroing error
selftests: KVM: extract lidt into helper function
selftests: KVM: Add test case for MMIO during vectoring
arch/x86/include/asm/kvm_host.h | 12 ++++-
arch/x86/kvm/kvm_emulate.h | 2 +
arch/x86/kvm/svm/svm.c | 9 +++-
arch/x86/kvm/vmx/vmx.c | 33 +++++-------
arch/x86/kvm/x86.c | 27 ++++++++++
.../selftests/kvm/include/x86_64/processor.h | 7 +++
.../selftests/kvm/set_memory_region_test.c | 53 ++++++++++++++++++-
.../selftests/kvm/x86_64/sev_smoke_test.c | 2 +-
8 files changed, 119 insertions(+), 26 deletions(-)
--
2.43.0
These patches are all simple fixes with no strong dependency though,
I hope that making them a patchset will be more convenient for merge.
The patchset are based on v6.12-rc2.
Chunyan Zhang (4):
riscv: Remove unused GENERATING_ASM_OFFSETS
riscv: Remove duplicated GET_RM
selftest/mm: Fix typo in virtual_address_range
selftests/mm: skip virtual_address_range tests on riscv
arch/riscv/kernel/asm-offsets.c | 2 --
arch/riscv/kernel/traps_misaligned.c | 2 --
tools/testing/selftests/mm/Makefile | 2 ++
tools/testing/selftests/mm/run_vmtests.sh | 10 ++++++----
tools/testing/selftests/mm/virtual_address_range.c | 4 ++--
5 files changed, 10 insertions(+), 10 deletions(-)
--
2.34.1
This series introduces a new ioctl KVM_TRANSLATE2, which expands on
KVM_TRANSLATE. It is required to implement Hyper-V's
HvTranslateVirtualAddress hyper-call as part of the ongoing effort to
emulate HyperV's Virtual Secure Mode (VSM) within KVM and QEMU. The hyper-
call requires several new KVM APIs, one of which is KVM_TRANSLATE2, which
implements the core functionality of the hyper-call. The rest of the
required functionality will be implemented in subsequent series.
Other than translating guest virtual addresses, the ioctl allows the
caller to control whether the access and dirty bits are set during the
page walk. It also allows specifying an access mode instead of returning
viable access modes, which enables setting the bits up to the level that
caused a failure. Additionally, the ioctl provides more information about
why the page walk failed, and which page table is responsible. This
functionality is not available within KVM_TRANSLATE, and can't be added
without breaking backwards compatiblity, thus a new ioctl is required.
The ioctl was designed to facilitate as many other use cases as possible
apart from VSM. The error codes were intentionally chosen to be broad
enough to avoid exposing architecture specific details. Even though
HvTranslateVirtualAddress only really needs one flag to set the accessed
and dirty bits whenever possible, that was split into several flags so
that future users can chose more gradually when these bits should be set.
Furthermore, as much information as possible is provided to the caller.
The patch series includes selftests for the ioctl, as well as fuzzy
testing on random garbage guest page table entries. All previously passing
KVM selftests and KVM unit tests still pass.
Series overview:
- 1: Document the new ioctl
- 2-11: Update the page walker in preparation
- 12-14: Implement the ioctl
- 15: Implement testing
This series, alongside the series by Nicolas Saenz Julienne [1]
introducing the core building blocks for VSM and the accompanying QEMU
implementation [2], is capable of booting Windows Server 2019.
Both series are also available on GitHub [3].
[1] https://lore.kernel.org/linux-hyperv/20240609154945.55332-1-nsaenz@amazon.c…
[2] https://github.com/vianpl/qemu/tree/vsm/next
[3] https://github.com/vianpl/linux/tree/vsm/next
Best,
Nikolas
Nikolas Wipper (15):
KVM: Add API documentation for KVM_TRANSLATE2
KVM: x86/mmu: Abort page walk if permission checks fail
KVM: x86/mmu: Introduce exception flag for unmapped GPAs
KVM: x86/mmu: Store GPA in exception if applicable
KVM: x86/mmu: Introduce flags parameter to page walker
KVM: x86/mmu: Implement PWALK_SET_ACCESSED in page walker
KVM: x86/mmu: Implement PWALK_SET_DIRTY in page walker
KVM: x86/mmu: Implement PWALK_FORCE_SET_ACCESSED in page walker
KVM: x86/mmu: Introduce status parameter to page walker
KVM: x86/mmu: Implement PWALK_STATUS_READ_ONLY_PTE_GPA in page walker
KVM: x86: Introduce generic gva to gpa translation function
KVM: Introduce KVM_TRANSLATE2
KVM: Add KVM_TRANSLATE2 stub
KVM: x86: Implement KVM_TRANSLATE2
KVM: selftests: Add test for KVM_TRANSLATE2
Documentation/virt/kvm/api.rst | 131 ++++++++
arch/x86/include/asm/kvm_host.h | 18 +-
arch/x86/kvm/hyperv.c | 3 +-
arch/x86/kvm/kvm_emulate.h | 8 +
arch/x86/kvm/mmu.h | 10 +-
arch/x86/kvm/mmu/mmu.c | 7 +-
arch/x86/kvm/mmu/paging_tmpl.h | 80 +++--
arch/x86/kvm/x86.c | 123 ++++++-
include/linux/kvm_host.h | 6 +
include/uapi/linux/kvm.h | 33 ++
tools/testing/selftests/kvm/Makefile | 1 +
.../selftests/kvm/x86_64/kvm_translate2.c | 310 ++++++++++++++++++
virt/kvm/kvm_main.c | 41 +++
13 files changed, 724 insertions(+), 47 deletions(-)
create mode 100644 tools/testing/selftests/kvm/x86_64/kvm_translate2.c
--
2.40.1
Amazon Web Services Development Center Germany GmbH
Krausenstr. 38
10117 Berlin
Geschaeftsfuehrung: Christian Schlaeger, Jonathan Weiss
Eingetragen am Amtsgericht Charlottenburg unter HRB 257764 B
Sitz: Berlin
Ust-ID: DE 365 538 597
This patch series provides workingset reporting of user pages in
lruvecs, of which coldness can be tracked by accessed bits and fd
references. However, the concept of workingset applies generically to
all types of memory, which could be kernel slab caches, discardable
userspace caches (databases), or CXL.mem. Therefore, data sources might
come from slab shrinkers, device drivers, or the userspace.
Another interesting idea might be hugepage workingset, so that we can
measure the proportion of hugepages backing cold memory. However, with
architectures like arm, there may be too many hugepage sizes leading to
a combinatorial explosion when exporting stats to the userspace.
Nonetheless, the kernel should provide a set of workingset interfaces
that is generic enough to accommodate the various use cases, and extensible
to potential future use cases.
Use cases
==========
Job scheduling
On overcommitted hosts, workingset information improves efficiency and
reliability by allowing the job scheduler to have better stats on the
exact memory requirements of each job. This can manifest in efficiency by
landing more jobs on the same host or NUMA node. On the other hand, the
job scheduler can also ensure each node has a sufficient amount of memory
and does not enter direct reclaim or the kernel OOM path. With workingset
information and job priority, the userspace OOM killing or proactive
reclaim policy can kick in before the system is under memory pressure.
If the job shape is very different from the machine shape, knowing the
workingset per-node can also help inform page allocation policies.
Proactive reclaim
Workingset information allows the a container manager to proactively
reclaim memory while not impacting a job's performance. While PSI may
provide a reactive measure of when a proactive reclaim has reclaimed too
much, workingset reporting allows the policy to be more accurate and
flexible.
Ballooning (similar to proactive reclaim)
The last patch of the series extends the virtio-balloon device to report
the guest workingset.
Balloon policies benefit from workingset to more precisely determine the
size of the memory balloon. On end-user devices where memory is scarce and
overcommitted, the balloon sizing in multiple VMs running on the same
device can be orchestrated with workingset reports from each one.
On the server side, workingset reporting allows the balloon controller to
inflate the balloon without causing too much file cache to be reclaimed in
the guest.
Promotion/Demotion
If different mechanisms are used for promition and demotion, workingset
information can help connect the two and avoid pages being migrated back
and forth.
For example, given a promotion hot page threshold defined in reaccess
distance of N seconds (promote pages accessed more often than every N
seconds). The threshold N should be set so that ~80% (e.g.) of pages on
the fast memory node passes the threshold. This calculation can be done
with workingset reports.
To be directly useful for promotion policies, the workingset report
interfaces need to be extended to report hotness and gather hotness
information from the devices[1].
[1]
https://www.opencompute.org/documents/ocp-cms-hotness-tracking-requirements…
Sysfs and Cgroup Interfaces
==========
The interfaces are detailed in the patches that introduce them. The main
idea here is we break down the workingset per-node per-memcg into time
intervals (ms), e.g.
1000 anon=137368 file=24530
20000 anon=34342 file=0
30000 anon=353232 file=333608
40000 anon=407198 file=206052
9223372036854775807 anon=4925624 file=892892
Implementation
==========
The reporting of user pages is based off of MGLRU, and therefore requires
CONFIG_LRU_GEN=y. We would benefit from more MGLRU generations for a more
fine-grained workingset report, but we can already gather a lot of data
with just four generations. The workingset reporting mechanism is gated
behind CONFIG_WORKINGSET_REPORT, and the aging thread is behind
CONFIG_WORKINGSET_REPORT_AGING.
Benchmarks
==========
Ghait Ouled Amar Ben Cheikh has implemented a simple policy and ran Linux
compile and redis benchmarks from openbenchmarking.org. The policy and
runner is referred to as WMO (Workload Memory Optimization).
The results were based on v3 of the series, but v4 doesn't change the core
of the working set reporting and just adds the ballooning counterpart.
The timed Linux kernel compilation benchmark shows improvements in peak
memory usage with a policy of "swap out all bytes colder than 10 seconds
every 40 seconds". A swapfile is configured on SSD.
--------------------------------------------
peak memory usage (with WMO): 4982.61328 MiB
peak memory usage (control): 9569.1367 MiB
peak memory reduction: 47.9%
--------------------------------------------
Benchmark | Experimental |Control | Experimental_Std_Dev | Control_Std_Dev
Timed Linux Kernel Compilation - allmodconfig (sec) | 708.486 (95.91%) | 679.499 (100%) | 0.6% | 0.1%
--------------------------------------------
Seconds, fewer is better
The redis benchmark shows employs the same policy:
--------------------------------------------
peak memory usage (with WMO): 375.9023 MiB
peak memory usage (control): 509.765 MiB
peak memory reduction: 26%
--------------------------------------------
Benchmark | Experimental | Control | Experimental_Std_Dev | Control_Std_Dev
Redis - LPOP (Reqs/sec) | 2023130 (98.22%) | 2059849 (100%) | 1.2% | 2%
Redis - SADD (Reqs/sec) | 2539662 (98.63%) | 2574811 (100%) | 2.3% | 1.4%
Redis - LPUSH (Reqs/sec)| 2024880 (100%) | 2000884 (98.81%) | 1.1% | 0.8%
Redis - GET (Reqs/sec) | 2835764 (100%) | 2763722 (97.46%) | 2.7% | 1.6%
Redis - SET (Reqs/sec) | 2340723 (100%) | 2327372 (99.43%) | 2.4% | 1.8%
--------------------------------------------
Reqs/sec, more is better
The detailed report and benchmarking results are in Ghait's repo:
https://github.com/miloudi98/WMO
Changelog
==========
Changes from PATCH v3 -> v4:
- Added documentation for cgroup-v2
(Waiman Long)
- Fixed types in documentation
(Randy Dunlap)
- Added implementation for the ballooning use case
- Added detailed description of benchmark results
(Andrew Morton)
Changes from PATCH v2 -> v3:
- Fixed typos in commit messages and documentation
(Lance Yang, Randy Dunlap)
- Split out the force_scan patch to be reviewed separately
- Added benchmarks from Ghait Ouled Amar Ben Cheikh
- Fixed reported compile error without CONFIG_MEMCG
Changes from PATCH v1 -> v2:
- Updated selftest to use ksft_test_result_code instead of switch-case
(Muhammad Usama Anjum)
- Included more use cases in the cover letter
(Huang, Ying)
- Added documentation for sysfs and memcg interfaces
- Added an aging-specific struct lru_gen_mm_walk in struct pglist_data
to avoid allocating for each lruvec.
[v1] https://lore.kernel.org/linux-mm/20240504073011.4000534-1-yuanchu@google.co…
[v2] https://lore.kernel.org/linux-mm/20240604020549.1017540-1-yuanchu@google.co…
[v3] https://lore.kernel.org/linux-mm/20240813165619.748102-1-yuanchu@google.com/
Yuanchu Xie (9):
mm: aggregate workingset information into histograms
mm: use refresh interval to rate-limit workingset report aggregation
mm: report workingset during memory pressure driven scanning
mm: extend workingset reporting to memcgs
mm: add kernel aging thread for workingset reporting
selftest: test system-wide workingset reporting
Docs/admin-guide/mm/workingset_report: document sysfs and memcg
interfaces
Docs/admin-guide/cgroup-v2: document workingset reporting
virtio-balloon: add workingset reporting
Documentation/admin-guide/cgroup-v2.rst | 35 +
Documentation/admin-guide/mm/index.rst | 1 +
.../admin-guide/mm/workingset_report.rst | 105 +++
drivers/base/node.c | 6 +
drivers/virtio/virtio_balloon.c | 390 ++++++++++-
include/linux/balloon_compaction.h | 1 +
include/linux/memcontrol.h | 21 +
include/linux/mmzone.h | 13 +
include/linux/workingset_report.h | 167 +++++
include/uapi/linux/virtio_balloon.h | 30 +
mm/Kconfig | 15 +
mm/Makefile | 2 +
mm/internal.h | 19 +
mm/memcontrol.c | 162 ++++-
mm/mm_init.c | 2 +
mm/mmzone.c | 2 +
mm/vmscan.c | 56 +-
mm/workingset_report.c | 653 ++++++++++++++++++
mm/workingset_report_aging.c | 127 ++++
tools/testing/selftests/mm/.gitignore | 1 +
tools/testing/selftests/mm/Makefile | 3 +
tools/testing/selftests/mm/run_vmtests.sh | 5 +
.../testing/selftests/mm/workingset_report.c | 306 ++++++++
.../testing/selftests/mm/workingset_report.h | 39 ++
.../selftests/mm/workingset_report_test.c | 330 +++++++++
25 files changed, 2482 insertions(+), 9 deletions(-)
create mode 100644 Documentation/admin-guide/mm/workingset_report.rst
create mode 100644 include/linux/workingset_report.h
create mode 100644 mm/workingset_report.c
create mode 100644 mm/workingset_report_aging.c
create mode 100644 tools/testing/selftests/mm/workingset_report.c
create mode 100644 tools/testing/selftests/mm/workingset_report.h
create mode 100644 tools/testing/selftests/mm/workingset_report_test.c
--
2.47.0.338.g60cca15819-goog