- Linux-kselftest-mirror - lists.linaro.org

[PATCH v7 0/8] ublk: decouple server threads from ublk_queues/hctxs

by Uday Shankar

This patch set aims to allow ublk server threads to better balance load amongst themselves by decoupling server threads from ublk_queues/hctxs, so that multiple threads can service I/Os that are issued from a single CPU. This can improve performance for workloads in which ublk server CPU is a bottleneck, and for which load is issued from CPUs which are not balanced across ublk_queues/hctxs. Performance ----------- First create two ublk devices with: ublkb0: ./kublk add -t null -q 2 --nthreads 2 ublkb1: ./kublk add -t null -q 2 --nthreads 2 --per_io_tasks Then run load with: taskset -c 1 fio/t/io_uring -r5 -p0 /dev/ublkb0: 1.90M IOPS taskset -c 1 fio/t/io_uring -r5 -p0 /dev/ublkb1: 2.18M IOPS Since ublkb1 has per-io-tasks, the second command is able to make use of both ublk server worker threads and therefore has increased max throughput. Caveats: - This testing was done on a system with 2 numa nodes, but the penalty of having I/O cross a numa (or LLC) boundary in the per_io_tasks case is quite high. So these numbers were obtained after moving all ublk server threads and the application threads to CPUs on the same numa node/LLC. - One might expect the scaling to be linear - because ublkb1 can make use of twice as many ublk server threads, it should be able to drive twice the throughput. However this is not true (the improvement is ~15%), and needs further investigation. Signed-off-by: Uday Shankar <ushankar(a)purestorage.com> --- Changes in v7: - Fix queue_rqs batch dispatch for per-io daemons - Kick round-robin tag allocation changes to a followup - Add explicit feature flag for per-task daemons (Ming Lei, Caleb Sander Mateos) - Move some variable assignments to avoid redundant computation (Caleb Sander Mateos) - Switch from storing pointers in ublk_io to computing based on address with container_of in a couple places (Ming Lei) - Link to v6: https://lore.kernel.org/r/20250507-ublk_task_per_io-v6-0-a2a298783c01@pures… Changes in v6: - Add a feature flag for this feature, called UBLK_F_RR_TAGS (Ming Lei) - Add test for this feature (Ming Lei) - Add documentation for this feature (Ming Lei) - Link to v5: https://lore.kernel.org/r/20250416-ublk_task_per_io-v5-0-9261ad7bff20@pures… Changes in v5: - Set io->task before ublk_mark_io_ready (Caleb Sander Mateos) - Set io->task atomically, read it atomically when needed - Return 0 on success from command-specific helpers in __ublk_ch_uring_cmd (Caleb Sander Mateos) - Rename ublk_handle_need_get_data to ublk_get_data (Caleb Sander Mateos) - Link to v4: https://lore.kernel.org/r/20250415-ublk_task_per_io-v4-0-54210b91a46f@pures… Changes in v4: - Drop "ublk: properly serialize all FETCH_REQs" since Ming is taking it in another set - Prevent data races by marking data structures which should be read-only in the I/O path as const (Ming Lei) - Link to v3: https://lore.kernel.org/r/20250410-ublk_task_per_io-v3-0-b811e8f4554a@pures… Changes in v3: - Check for UBLK_IO_FLAG_ACTIVE on I/O again after taking lock to ensure that two concurrent FETCH_REQs on the same I/O can't succeed (Caleb Sander Mateos) - Link to v2: https://lore.kernel.org/r/20250408-ublk_task_per_io-v2-0-b97877e6fd50@pures… Changes in v2: - Remove changes split into other patches - To ease error handling/synchronization, associate each I/O (instead of each queue) to the last task that issues a FETCH_REQ against it. Only that task is allowed to operate on the I/O. - Link to v1: https://lore.kernel.org/r/20241002224437.3088981-1-ushankar@purestorage.com --- Uday Shankar (8): ublk: have a per-io daemon instead of a per-queue daemon selftests: ublk: kublk: plumb q_id in io_uring user_data selftests: ublk: kublk: tie sqe allocation to io instead of queue selftests: ublk: kublk: lift queue initialization out of thread selftests: ublk: kublk: move per-thread data out of ublk_queue selftests: ublk: kublk: decouple ublk_queues from ublk server threads selftests: ublk: add test for per io daemons Documentation: ublk: document UBLK_F_PER_IO_DAEMON Documentation/block/ublk.rst | 35 ++- drivers/block/ublk_drv.c | 108 +++---- include/uapi/linux/ublk_cmd.h | 9 + tools/testing/selftests/ublk/Makefile | 1 + tools/testing/selftests/ublk/fault_inject.c | 4 +- tools/testing/selftests/ublk/file_backed.c | 20 +- tools/testing/selftests/ublk/kublk.c | 345 ++++++++++++++------- tools/testing/selftests/ublk/kublk.h | 73 +++-- tools/testing/selftests/ublk/null.c | 22 +- tools/testing/selftests/ublk/stripe.c | 17 +- tools/testing/selftests/ublk/test_generic_12.sh | 55 ++++ .../selftests/ublk/trace/count_ios_per_tid.bt | 11 + 12 files changed, 470 insertions(+), 230 deletions(-) --- base-commit: 533c87e2ed742454957f14d7bef9f48d5a72e72d change-id: 20250408-ublk_task_per_io-c693cf608d7a Best regards, -- Uday Shankar <ushankar(a)purestorage.com>

12 hours, 6 minutes

3
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[PATCH] kunit: configs: Enable CONFIG_INIT_STACK_ALL_PATTERN in all_tests

by Richard Fitzgerald

Enable CONFIG_INIT_STACK_ALL_PATTERN in all_tests.config. This helps to detect use of uninitialized local variables. This option found an uninitialized data bug in the cs_dsp test. Signed-off-by: Richard Fitzgerald <rf(a)opensource.cirrus.com> --- tools/testing/kunit/configs/all_tests.config | 1 + 1 file changed, 1 insertion(+) diff --git a/tools/testing/kunit/configs/all_tests.config b/tools/testing/kunit/configs/all_tests.config index cdd9782f9646..4a60bb71fe72 100644 --- a/tools/testing/kunit/configs/all_tests.config +++ b/tools/testing/kunit/configs/all_tests.config @@ -10,6 +10,7 @@ CONFIG_KUNIT_EXAMPLE_TEST=y CONFIG_KUNIT_ALL_TESTS=y CONFIG_FORTIFY_SOURCE=y +CONFIG_INIT_STACK_ALL_PATTERN=y CONFIG_IIO=y -- 2.39.5

12 hours, 7 minutes

3
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[PATCH v3] rust: kunit: use crate-level mapping for `c_void`

by Jesung Yang

Remove `use core::ffi::c_void`, which shadows `kernel::ffi::c_void` brought in via `use crate::prelude::*`, to maintain consistency and centralize the abstraction. Since `kernel::ffi::c_void` is a straightforward re-export of `core::ffi::c_void`, both are functionally equivalent. However, using `kernel::ffi::c_void` improves consistency across the kernel's Rust code and provides a unified reference point in case the definition ever needs to change, even if such a change is unlikely. Reviewed-by: Benno Lossin <lossin(a)kernel.org> Signed-off-by: Jesung Yang <y.j3ms.n(a)gmail.com> Link: https://rust-for-linux.zulipchat.com/#narrow/channel/288089/topic/x/near/52… --- Changes in v3: - Rebase on a3b2347343e0 - Remove the explicit import of `kernel::ffi::c_void` - Reword the commit message accordingly - Link to v2: https://lore.kernel.org/rust-for-linux/20250528155147.2793921-1-y.j3ms.n@gm… Changes in v2: - Add "Link" tag to the related discussion on Zulip - Reword the commit message to clarify `kernel::ffi::c_void` is a re-export - Link to v1: https://lore.kernel.org/rust-for-linux/20250526162429.1114862-1-y.j3ms.n@gm… --- rust/kernel/kunit.rs | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/rust/kernel/kunit.rs b/rust/kernel/kunit.rs index 4b8cdcb21e77..603330f247c7 100644 --- a/rust/kernel/kunit.rs +++ b/rust/kernel/kunit.rs @@ -7,7 +7,7 @@ //! Reference: <https://docs.kernel.org/dev-tools/kunit/index.html> use crate::prelude::*; -use core::{ffi::c_void, fmt}; +use core::fmt; /// Prints a KUnit error-level message. /// base-commit: a3b2347343e077e81d3c169f32c9b2cb1364f4cc -- 2.39.5

14 hours, 52 minutes

2
1
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[PATCH v8 00/14] riscv: add SBI FWFT misaligned exception delegation support

by Clément Léger

The SBI Firmware Feature extension allows the S-mode to request some specific features (either hardware or software) to be enabled. This series uses this extension to request misaligned access exception delegation to S-mode in order to let the kernel handle it. It also adds support for the KVM FWFT SBI extension based on the misaligned access handling infrastructure. FWFT SBI extension is part of the SBI V3.0 specifications [1]. It can be tested using the qemu provided at [2] which contains the series from [3]. Upstream kvm-unit-tests can be used inside kvm to tests the correct delegation of misaligned exceptions. Upstream OpenSBI can be used. Note: Since SBI V3.0 is not yet ratified, FWFT extension API is split between interface only and implementation, allowing to pick only the interface which do not have hard dependencies on SBI. The tests can be run using the kselftest from series [4]. $ qemu-system-riscv64 \ -cpu rv64,trap-misaligned-access=true,v=true \ -M virt \ -m 1024M \ -bios fw_dynamic.bin \ -kernel Image ... # ./misaligned TAP version 13 1..23 # Starting 23 tests from 1 test cases. # RUN global.gp_load_lh ... # OK global.gp_load_lh ok 1 global.gp_load_lh # RUN global.gp_load_lhu ... # OK global.gp_load_lhu ok 2 global.gp_load_lhu # RUN global.gp_load_lw ... # OK global.gp_load_lw ok 3 global.gp_load_lw # RUN global.gp_load_lwu ... # OK global.gp_load_lwu ok 4 global.gp_load_lwu # RUN global.gp_load_ld ... # OK global.gp_load_ld ok 5 global.gp_load_ld # RUN global.gp_load_c_lw ... # OK global.gp_load_c_lw ok 6 global.gp_load_c_lw # RUN global.gp_load_c_ld ... # OK global.gp_load_c_ld ok 7 global.gp_load_c_ld # RUN global.gp_load_c_ldsp ... # OK global.gp_load_c_ldsp ok 8 global.gp_load_c_ldsp # RUN global.gp_load_sh ... # OK global.gp_load_sh ok 9 global.gp_load_sh # RUN global.gp_load_sw ... # OK global.gp_load_sw ok 10 global.gp_load_sw # RUN global.gp_load_sd ... # OK global.gp_load_sd ok 11 global.gp_load_sd # RUN global.gp_load_c_sw ... # OK global.gp_load_c_sw ok 12 global.gp_load_c_sw # RUN global.gp_load_c_sd ... # OK global.gp_load_c_sd ok 13 global.gp_load_c_sd # RUN global.gp_load_c_sdsp ... # OK global.gp_load_c_sdsp ok 14 global.gp_load_c_sdsp # RUN global.fpu_load_flw ... # OK global.fpu_load_flw ok 15 global.fpu_load_flw # RUN global.fpu_load_fld ... # OK global.fpu_load_fld ok 16 global.fpu_load_fld # RUN global.fpu_load_c_fld ... # OK global.fpu_load_c_fld ok 17 global.fpu_load_c_fld # RUN global.fpu_load_c_fldsp ... # OK global.fpu_load_c_fldsp ok 18 global.fpu_load_c_fldsp # RUN global.fpu_store_fsw ... # OK global.fpu_store_fsw ok 19 global.fpu_store_fsw # RUN global.fpu_store_fsd ... # OK global.fpu_store_fsd ok 20 global.fpu_store_fsd # RUN global.fpu_store_c_fsd ... # OK global.fpu_store_c_fsd ok 21 global.fpu_store_c_fsd # RUN global.fpu_store_c_fsdsp ... # OK global.fpu_store_c_fsdsp ok 22 global.fpu_store_c_fsdsp # RUN global.gen_sigbus ... [12797.988647] misaligned[618]: unhandled signal 7 code 0x1 at 0x0000000000014dc0 in misaligned[4dc0,10000+76000] [12797.988990] CPU: 0 UID: 0 PID: 618 Comm: misaligned Not tainted 6.13.0-rc6-00008-g4ec4468967c9-dirty #51 [12797.989169] Hardware name: riscv-virtio,qemu (DT) [12797.989264] epc : 0000000000014dc0 ra : 0000000000014d00 sp : 00007fffe165d100 [12797.989407] gp : 000000000008f6e8 tp : 0000000000095760 t0 : 0000000000000008 [12797.989544] t1 : 00000000000965d8 t2 : 000000000008e830 s0 : 00007fffe165d160 [12797.989692] s1 : 000000000000001a a0 : 0000000000000000 a1 : 0000000000000002 [12797.989831] a2 : 0000000000000000 a3 : 0000000000000000 a4 : ffffffffdeadbeef [12797.989964] a5 : 000000000008ef61 a6 : 626769735f6e0000 a7 : fffffffffffff000 [12797.990094] s2 : 0000000000000001 s3 : 00007fffe165d838 s4 : 00007fffe165d848 [12797.990238] s5 : 000000000000001a s6 : 0000000000010442 s7 : 0000000000010200 [12797.990391] s8 : 000000000000003a s9 : 0000000000094508 s10: 0000000000000000 [12797.990526] s11: 0000555567460668 t3 : 00007fffe165d070 t4 : 00000000000965d0 [12797.990656] t5 : fefefefefefefeff t6 : 0000000000000073 [12797.990756] status: 0000000200004020 badaddr: 000000000008ef61 cause: 0000000000000006 [12797.990911] Code: 8793 8791 3423 fcf4 3783 fc84 c737 dead 0713 eef7 (c398) 0001 # OK global.gen_sigbus ok 23 global.gen_sigbus # PASSED: 23 / 23 tests passed. # Totals: pass:23 fail:0 xfail:0 xpass:0 skip:0 error:0 With kvm-tools: # lkvm run -k sbi.flat -m 128 Info: # lkvm run -k sbi.flat -m 128 -c 1 --name guest-97 Info: Removed ghost socket file "/root/.lkvm//guest-97.sock". ########################################################################## # kvm-unit-tests ########################################################################## ... [test messages elided] PASS: sbi: fwft: FWFT extension probing no error PASS: sbi: fwft: get/set reserved feature 0x6 error == SBI_ERR_DENIED PASS: sbi: fwft: get/set reserved feature 0x3fffffff error == SBI_ERR_DENIED PASS: sbi: fwft: get/set reserved feature 0x80000000 error == SBI_ERR_DENIED PASS: sbi: fwft: get/set reserved feature 0xbfffffff error == SBI_ERR_DENIED PASS: sbi: fwft: misaligned_deleg: Get misaligned deleg feature no error PASS: sbi: fwft: misaligned_deleg: Set misaligned deleg feature invalid value error PASS: sbi: fwft: misaligned_deleg: Set misaligned deleg feature invalid value error PASS: sbi: fwft: misaligned_deleg: Set misaligned deleg feature value no error PASS: sbi: fwft: misaligned_deleg: Set misaligned deleg feature value 0 PASS: sbi: fwft: misaligned_deleg: Set misaligned deleg feature value no error PASS: sbi: fwft: misaligned_deleg: Set misaligned deleg feature value 1 PASS: sbi: fwft: misaligned_deleg: Verify misaligned load exception trap in supervisor SUMMARY: 50 tests, 2 unexpected failures, 12 skipped This series is available at [5]. Link: https://github.com/riscv-non-isa/riscv-sbi-doc/releases/download/vv3.0-rc2/… [1] Link: https://github.com/rivosinc/qemu/tree/dev/cleger/misaligned [2] Link: https://lore.kernel.org/all/20241211211933.198792-3-fkonrad@amd.com/T/ [3] Link: https://lore.kernel.org/linux-riscv/20250414123543.1615478-1-cleger@rivosin… [4] Link: https://github.com/rivosinc/linux/tree/dev/cleger/fwft [5] --- V8: - Move misaligned_access_speed under CONFIG_RISCV_MISALIGNED and add a separate commit for that. V7: - Fix ifdefery build problems - Move sbi_fwft_is_supported with fwft_set_req struct - Added Atish Reviewed-by - Updated KVM vcpu cfg hedeleg value in set_delegation - Changed SBI ETIME error mapping to ETIMEDOUT - Fixed a few typo reported by Alok V6: - Rename FWFT interface to remove "_local" - Fix test for MEDELEG values in KVM FWFT support - Add __init for unaligned_access_init() - Rebased on master V5: - Return ERANGE as mapping for SBI_ERR_BAD_RANGE - Removed unused sbi_fwft_get() - Fix kernel for sbi_fwft_local_set_cpumask() - Fix indentation for sbi_fwft_local_set() - Remove spurious space in kvm_sbi_fwft_ops. - Rebased on origin/master - Remove fixes commits and sent them as a separate series [4] V4: - Check SBI version 3.0 instead of 2.0 for FWFT presence - Use long for kvm_sbi_fwft operation return value - Init KVM sbi extension even if default_disabled - Remove revert_on_fail parameter for sbi_fwft_feature_set(). - Fix comments for sbi_fwft_set/get() - Only handle local features (there are no globals yet in the spec) - Add new SBI errors to sbi_err_map_linux_errno() V3: - Added comment about kvm sbi fwft supported/set/get callback requirements - Move struct kvm_sbi_fwft_feature in kvm_sbi_fwft.c - Add a FWFT interface V2: - Added Kselftest for misaligned testing - Added get_user() usage instead of __get_user() - Reenable interrupt when possible in misaligned access handling - Document that riscv supports unaligned-traps - Fix KVM extension state when an init function is present - Rework SBI misaligned accesses trap delegation code - Added support for CPU hotplugging - Added KVM SBI reset callback - Added reset for KVM SBI FWFT lock - Return SBI_ERR_DENIED_LOCKED when LOCK flag is set Clément Léger (14): riscv: sbi: add Firmware Feature (FWFT) SBI extensions definitions riscv: sbi: remove useless parenthesis riscv: sbi: add new SBI error mappings riscv: sbi: add FWFT extension interface riscv: sbi: add SBI FWFT extension calls riscv: misaligned: request misaligned exception from SBI riscv: misaligned: use on_each_cpu() for scalar misaligned access probing riscv: misaligned: declare misaligned_access_speed under CONFIG_RISCV_MISALIGNED riscv: misaligned: move emulated access uniformity check in a function riscv: misaligned: add a function to check misalign trap delegability RISC-V: KVM: add SBI extension init()/deinit() functions RISC-V: KVM: add SBI extension reset callback RISC-V: KVM: add support for FWFT SBI extension RISC-V: KVM: add support for SBI_FWFT_MISALIGNED_DELEG arch/riscv/include/asm/cpufeature.h | 14 +- arch/riscv/include/asm/kvm_host.h | 5 +- arch/riscv/include/asm/kvm_vcpu_sbi.h | 12 + arch/riscv/include/asm/kvm_vcpu_sbi_fwft.h | 29 +++ arch/riscv/include/asm/sbi.h | 60 +++++ arch/riscv/include/uapi/asm/kvm.h | 1 + arch/riscv/kernel/sbi.c | 81 ++++++- arch/riscv/kernel/traps_misaligned.c | 112 ++++++++- arch/riscv/kernel/unaligned_access_speed.c | 8 +- arch/riscv/kvm/Makefile | 1 + arch/riscv/kvm/vcpu.c | 4 +- arch/riscv/kvm/vcpu_sbi.c | 54 +++++ arch/riscv/kvm/vcpu_sbi_fwft.c | 257 +++++++++++++++++++++ arch/riscv/kvm/vcpu_sbi_sta.c | 3 +- 14 files changed, 620 insertions(+), 21 deletions(-) create mode 100644 arch/riscv/include/asm/kvm_vcpu_sbi_fwft.h create mode 100644 arch/riscv/kvm/vcpu_sbi_fwft.c -- 2.49.0

15 hours, 2 minutes

5
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[RFC PATCH v2 0/9] KVM: Enable Nested Virt selftests

by Ganapatrao Kulkarni

This patch series makes the selftest work with NV enabled. The guest code is run in vEL2 instead of EL1. We add a command line option to enable testing of NV. The NV tests are disabled by default. Modified around 12 selftests in this series. Changes since v1: - Updated NV helper functions as per comments [1]. - Modified existing testscases to run guest code in vEL2. [1] https://lkml.iu.edu/hypermail/linux/kernel/2502.0/07001.html Ganapatrao Kulkarni (9): KVM: arm64: nv: selftests: Add support to run guest code in vEL2. KVM: arm64: nv: selftests: Add simple test to run guest code in vEL2 KVM: arm64: nv: selftests: Enable hypervisor timer tests to run in vEL2 KVM: arm64: nv: selftests: enable aarch32_id_regs test to run in vEL2 KVM: arm64: nv: selftests: Enable vgic tests to run in vEL2 KVM: arm64: nv: selftests: Enable set_id_regs test to run in vEL2 KVM: arm64: nv: selftests: Enable test to run in vEL2 KVM: selftests: arm64: Extend kvm_page_table_test to run guest code in vEL2 KVM: arm64: nv: selftests: Enable page_fault_test test to run in vEL2 tools/testing/selftests/kvm/Makefile.kvm | 2 + tools/testing/selftests/kvm/arch_timer.c | 8 +- .../selftests/kvm/arm64/aarch32_id_regs.c | 34 ++++- .../testing/selftests/kvm/arm64/arch_timer.c | 118 +++++++++++++++--- .../selftests/kvm/arm64/nv_guest_hypervisor.c | 68 ++++++++++ .../selftests/kvm/arm64/page_fault_test.c | 35 +++++- .../testing/selftests/kvm/arm64/set_id_regs.c | 57 ++++++++- tools/testing/selftests/kvm/arm64/vgic_init.c | 54 +++++++- tools/testing/selftests/kvm/arm64/vgic_irq.c | 27 ++-- .../selftests/kvm/arm64/vgic_lpi_stress.c | 19 ++- .../testing/selftests/kvm/guest_print_test.c | 32 +++++ .../selftests/kvm/include/arm64/arch_timer.h | 16 +++ .../kvm/include/arm64/kvm_util_arch.h | 3 + .../selftests/kvm/include/arm64/nv_util.h | 45 +++++++ .../selftests/kvm/include/arm64/vgic.h | 1 + .../testing/selftests/kvm/include/kvm_util.h | 3 + .../selftests/kvm/include/timer_test.h | 1 + .../selftests/kvm/kvm_page_table_test.c | 30 ++++- tools/testing/selftests/kvm/lib/arm64/nv.c | 46 +++++++ .../selftests/kvm/lib/arm64/processor.c | 61 ++++++--- tools/testing/selftests/kvm/lib/arm64/vgic.c | 8 ++ 21 files changed, 604 insertions(+), 64 deletions(-) create mode 100644 tools/testing/selftests/kvm/arm64/nv_guest_hypervisor.c create mode 100644 tools/testing/selftests/kvm/include/arm64/nv_util.h create mode 100644 tools/testing/selftests/kvm/lib/arm64/nv.c -- 2.48.1

15 hours, 54 minutes

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[PATCH v6 0/4] mm: introduce THP deferred setting

by Nico Pache

This series is a follow-up to [1], which adds mTHP support to khugepaged. mTHP khugepaged support is a "loose" dependency for the sysfs/sysctl configs to make sense. Without it global="defer" and mTHP="inherit" case is "undefined" behavior. We've seen cases were customers switching from RHEL7 to RHEL8 see a significant increase in the memory footprint for the same workloads. Through our investigations we found that a large contributing factor to the increase in RSS was an increase in THP usage. For workloads like MySQL, or when using allocators like jemalloc, it is often recommended to set /transparent_hugepages/enabled=never. This is in part due to performance degradations and increased memory waste. This series introduces enabled=defer, this setting acts as a middle ground between always and madvise. If the mapping is MADV_HUGEPAGE, the page fault handler will act normally, making a hugepage if possible. If the allocation is not MADV_HUGEPAGE, then the page fault handler will default to the base size allocation. The caveat is that khugepaged can still operate on pages that are not MADV_HUGEPAGE. This allows for three things... one, applications specifically designed to use hugepages will get them, and two, applications that don't use hugepages can still benefit from them without aggressively inserting THPs at every possible chance. This curbs the memory waste, and defers the use of hugepages to khugepaged. Khugepaged can then scan the memory for eligible collapsing. Lastly there is the added benefit for those who want THPs but experience higher latency PFs. Now you can get base page performance at the PF handler and Hugepage performance for those mappings after they collapse. Admins may want to lower max_ptes_none, if not, khugepaged may aggressively collapse single allocations into hugepages. TESTING: - Built for x86_64, aarch64, ppc64le, and s390x - selftests mm - In [1] I provided a script [2] that has multiple access patterns - lots of general use. - redis testing. This test was my original case for the defer mode. What I was able to prove was that THP=always leads to increased max_latency cases; hence why it is recommended to disable THPs for redis servers. However with 'defer' we dont have the max_latency spikes and can still get the system to utilize THPs. I further tested this with the mTHP defer setting and found that redis (and probably other jmalloc users) can utilize THPs via defer (+mTHP defer) without a large latency penalty and some potential gains. I uploaded some mmtest results here[3] which compares: stock+thp=never stock+(m)thp=always khugepaged-mthp + defer (max_ptes_none=64) The results show that (m)THPs can cause some throughput regression in some cases, but also has gains in other cases. The mTHP+defer results have more gains and less losses over the (m)THP=always case. V6 Changes: - nits - rebased dependent series and added review tags V5 Changes: - rebased dependent series - added reviewed-by tag on 2/4 V4 Changes: - Minor Documentation fixes - rebased the dependent series [1] onto mm-unstable commit 0e68b850b1d3 ("vmalloc: use atomic_long_add_return_relaxed()") V3 Changes: - Combined the documentation commits into one, and moved a section to the khugepaged mthp patchset V2 Changes: - base changes on mTHP khugepaged support - Fix selftests parsing issue - add mTHP defer option - add mTHP defer Documentation [1] - https://lore.kernel.org/all/20250515032226.128900-1-npache@redhat.com/ [2] - https://gitlab.com/npache/khugepaged_mthp_test [3] - https://people.redhat.com/npache/mthp_khugepaged_defer/testoutput2/output.h… Nico Pache (4): mm: defer THP insertion to khugepaged mm: document (m)THP defer usage khugepaged: add defer option to mTHP options selftests: mm: add defer to thp setting parser Documentation/admin-guide/mm/transhuge.rst | 31 +++++++--- include/linux/huge_mm.h | 18 +++++- mm/huge_memory.c | 69 +++++++++++++++++++--- mm/khugepaged.c | 8 +-- tools/testing/selftests/mm/thp_settings.c | 1 + tools/testing/selftests/mm/thp_settings.h | 1 + 6 files changed, 106 insertions(+), 22 deletions(-) -- 2.49.0

23 hours, 19 minutes

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[PATCH bpf-next 2/2] selftests/bpf: Add selftests for bpf_task_cwd_from_pid()

by Rong Tao

From: Rong Tao <rongtao(a)cestc.cn> Add some selftest testcases that validate the expected behavior of the bpf_task_cwd_from_pid() kfunc that was added in the prior patch. Signed-off-by: Rong Tao <rongtao(a)cestc.cn> --- .../selftests/bpf/prog_tests/task_kfunc.c | 3 ++ .../selftests/bpf/progs/task_kfunc_common.h | 1 + .../selftests/bpf/progs/task_kfunc_success.c | 47 +++++++++++++++++++ 3 files changed, 51 insertions(+) diff --git a/tools/testing/selftests/bpf/prog_tests/task_kfunc.c b/tools/testing/selftests/bpf/prog_tests/task_kfunc.c index 83b90335967a..c18a0cb67164 100644 --- a/tools/testing/selftests/bpf/prog_tests/task_kfunc.c +++ b/tools/testing/selftests/bpf/prog_tests/task_kfunc.c @@ -149,6 +149,9 @@ static const char * const success_tests[] = { "task_kfunc_acquire_trusted_walked", "test_task_kfunc_flavor_relo", "test_task_kfunc_flavor_relo_not_found", + "test_task_cwd_from_pid_arg", + "test_task_cwd_from_pid", + "test_task_cwd_from_pid_current", }; static const char * const vpid_success_tests[] = { diff --git a/tools/testing/selftests/bpf/progs/task_kfunc_common.h b/tools/testing/selftests/bpf/progs/task_kfunc_common.h index e9c4fea7a4bb..b762054a1825 100644 --- a/tools/testing/selftests/bpf/progs/task_kfunc_common.h +++ b/tools/testing/selftests/bpf/progs/task_kfunc_common.h @@ -24,6 +24,7 @@ struct task_struct *bpf_task_acquire(struct task_struct *p) __ksym; void bpf_task_release(struct task_struct *p) __ksym; struct task_struct *bpf_task_from_pid(s32 pid) __ksym; struct task_struct *bpf_task_from_vpid(s32 vpid) __ksym; +int bpf_task_cwd_from_pid(s32 pid, char *buf, u32 buf_len) __ksym; void bpf_rcu_read_lock(void) __ksym; void bpf_rcu_read_unlock(void) __ksym; diff --git a/tools/testing/selftests/bpf/progs/task_kfunc_success.c b/tools/testing/selftests/bpf/progs/task_kfunc_success.c index 5fb4fc19d26a..6424cf5c151e 100644 --- a/tools/testing/selftests/bpf/progs/task_kfunc_success.c +++ b/tools/testing/selftests/bpf/progs/task_kfunc_success.c @@ -351,6 +351,53 @@ int BPF_PROG(test_task_from_pid_invalid, struct task_struct *task, u64 clone_fla return 0; } +SEC("tp_btf/task_newtask") +int BPF_PROG(test_task_cwd_from_pid_arg, struct task_struct *task, u64 clone_flags) +{ + char cwd[256]; + + if (!is_test_kfunc_task()) + return 0; + + err = 0; + err += bpf_task_cwd_from_pid(task->pid, NULL, sizeof(cwd)) != -EINVAL; + err += bpf_task_cwd_from_pid(task->pid, cwd, 0) != -EINVAL; + err += bpf_task_cwd_from_pid(-1, cwd, sizeof(cwd)) != -ESRCH; + return 0; +} + +SEC("tp_btf/task_newtask") +int BPF_PROG(test_task_cwd_from_pid, struct task_struct *task, u64 clone_flags) +{ + char cwd[256]; + + if (!is_test_kfunc_task()) + return 0; + + err = bpf_task_cwd_from_pid(task->pid, cwd, sizeof(cwd)); + return 0; +} + +SEC("tp_btf/task_newtask") +int BPF_PROG(test_task_cwd_from_pid_current, struct task_struct *task, u64 clone_flags) +{ + char cwd[128], cwd2[128]; + struct task_struct *current; + + if (!is_test_kfunc_task()) + return 0; + + current = bpf_get_current_task_btf(); + + err = 0; + err += bpf_task_cwd_from_pid(task->pid, cwd, sizeof(cwd)); + err += bpf_task_cwd_from_pid(current->pid, cwd2, sizeof(cwd2)); + + err += bpf_strncmp(cwd, sizeof(cwd), cwd2) != 0; + + return 0; +} + SEC("tp_btf/task_newtask") int BPF_PROG(task_kfunc_acquire_trusted_walked, struct task_struct *task, u64 clone_flags) { -- 2.49.0

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[PATCH bpf-next 0/2] Add kfunc for doing pid -> task cwd

by Rong Tao

In some application like bpftrace [1], need to get the cwd from the pid. This patch provides a new kfunc that can get the cwd of the process from the pid. [1] https://github.com/bpftrace/bpftrace/issues/3314 Rong Tao (2): bpf: Add bpf_task_cwd_from_pid() kfunc selftests/bpf: Add selftests for bpf_task_cwd_from_pid() kernel/bpf/helpers.c | 45 ++++++++++++++++++ .../selftests/bpf/prog_tests/task_kfunc.c | 3 ++ .../selftests/bpf/progs/task_kfunc_common.h | 1 + .../selftests/bpf/progs/task_kfunc_success.c | 47 +++++++++++++++++++ 4 files changed, 96 insertions(+) -- 2.49.0

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[PATCH net-next] selftest: Add selftest for multicast address notifications

by Yuyang Huang

This commit adds a new kernel selftest to verify RTNLGRP_IPV4_MCADDR and RTNLGRP_IPV6_MCADDR notifications. The test works by adding and removing a dummy interface and then confirming that the system correctly receives join and removal notifications for the 224.0.0.1 and ff02::1 multicast addresses. The test relies on the iproute2 version to be 6.13+. Tested by the following command: $ vng -v --user root --cpus 16 -- \ make -C tools/testing/selftests TARGETS=net TEST_PROGS=rtnetlink.sh \ TEST_GEN_PROGS="" run_tests Cc: Maciej Żenczykowski <maze(a)google.com> Cc: Lorenzo Colitti <lorenzo(a)google.com> Signed-off-by: Yuyang Huang <yuyanghuang(a)google.com> --- tools/testing/selftests/net/rtnetlink.sh | 34 ++++++++++++++++++++++++ 1 file changed, 34 insertions(+) diff --git a/tools/testing/selftests/net/rtnetlink.sh b/tools/testing/selftests/net/rtnetlink.sh index 2e8243a65b50..9dbcaaeaf8cd 100755 --- a/tools/testing/selftests/net/rtnetlink.sh +++ b/tools/testing/selftests/net/rtnetlink.sh @@ -21,6 +21,7 @@ ALL_TESTS=" kci_test_vrf kci_test_encap kci_test_macsec + kci_test_mcast_addr_notification kci_test_ipsec kci_test_ipsec_offload kci_test_fdb_get @@ -1334,6 +1335,39 @@ kci_test_mngtmpaddr() return $ret } +kci_test_mcast_addr_notification() +{ + local tmpfile + local monitor_pid + local match_result + + tmpfile=$(mktemp) + + ip monitor maddr > $tmpfile & + monitor_pid=$! + sleep 1 + + run_cmd ip link add name test-dummy1 type dummy + run_cmd ip link set test-dummy1 up + run_cmd ip link del dev test-dummy1 + sleep 1 + + match_result=$(grep -cE "test-dummy1.*(224.0.0.1|ff02::1)" $tmpfile) + + kill $monitor_pid + rm $tmpfile + # There should be 4 line matches as follows. + # 13: test-dummy1 inet6 mcast ff02::1 scope global + # 13: test-dummy1 inet mcast 224.0.0.1 scope global + # Deleted 13: test-dummy1 inet mcast 224.0.0.1 scope global + # Deleted 13: test-dummy1 inet6 mcast ff02::1 scope global + if [ $match_result -ne 4 ];then + end_test "FAIL: mcast addr notification" + return 1 + fi + end_test "PASS: mcast addr notification" +} + kci_test_rtnl() { local current_test -- 2.49.0.1204.g71687c7c1d-goog

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[PATCH] selftests: Add version file to kselftest installation dir

by Tianyi Cui

As titled, adding version file to kselftest installation dir, so the user of the tarball can know which kernel version the tarball belongs to. Signed-off-by: Tianyi Cui <1997cui(a)gmail.com> --- tools/testing/selftests/Makefile | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile index a0a6ba47d600..246e9863b45b 100644 --- a/tools/testing/selftests/Makefile +++ b/tools/testing/selftests/Makefile @@ -291,6 +291,12 @@ ifdef INSTALL_PATH $(MAKE) -s --no-print-directory OUTPUT=$$BUILD_TARGET COLLECTION=$$TARGET \ -C $$TARGET emit_tests >> $(TEST_LIST); \ done; + @if git describe HEAD > /dev/null 2>&1; then \ + git describe HEAD > $(INSTALL_PATH)/VERSION; \ + printf "Version saved to $(INSTALL_PATH)/VERSION\n"; \ + else \ + printf "Unable to get version from git describe\n"; \ + fi else $(error Error: set INSTALL_PATH to use install) endif -- 2.47.1

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