April 2025 - Linux-kselftest-mirror

[PATCH v5 00/25] context_tracking,x86: Defer some IPIs until a user->kernel transition

by Valentin Schneider

Context ======= We've observed within Red Hat that isolated, NOHZ_FULL CPUs running a pure-userspace application get regularly interrupted by IPIs sent from housekeeping CPUs. Those IPIs are caused by activity on the housekeeping CPUs leading to various on_each_cpu() calls, e.g.: 64359.052209596 NetworkManager 0 1405 smp_call_function_many_cond (cpu=0, func=do_kernel_range_flush) smp_call_function_many_cond+0x1 smp_call_function+0x39 on_each_cpu+0x2a flush_tlb_kernel_range+0x7b __purge_vmap_area_lazy+0x70 _vm_unmap_aliases.part.42+0xdf change_page_attr_set_clr+0x16a set_memory_ro+0x26 bpf_int_jit_compile+0x2f9 bpf_prog_select_runtime+0xc6 bpf_prepare_filter+0x523 sk_attach_filter+0x13 sock_setsockopt+0x92c __sys_setsockopt+0x16a __x64_sys_setsockopt+0x20 do_syscall_64+0x87 entry_SYSCALL_64_after_hwframe+0x65 The heart of this series is the thought that while we cannot remove NOHZ_FULL CPUs from the list of CPUs targeted by these IPIs, they may not have to execute the callbacks immediately. Anything that only affects kernelspace can wait until the next user->kernel transition, providing it can be executed "early enough" in the entry code. The original implementation is from Peter [1]. Nicolas then added kernel TLB invalidation deferral to that [2], and I picked it up from there. Deferral approach ================= Storing each and every callback, like a secondary call_single_queue turned out to be a no-go: the whole point of deferral is to keep NOHZ_FULL CPUs in userspace for as long as possible - no signal of any form would be sent when deferring an IPI. This means that any form of queuing for deferred callbacks would end up as a convoluted memory leak. Deferred IPIs must thus be coalesced, which this series achieves by assigning IPIs a "type" and having a mapping of IPI type to callback, leveraged upon kernel entry. What about IPIs whose callback take a parameter, you may ask? Peter suggested during OSPM23 [3] that since on_each_cpu() targets housekeeping CPUs *and* isolated CPUs, isolated CPUs can access either global or housekeeping-CPU-local state to "reconstruct" the data that would have been sent via the IPI. This series does not affect any IPI callback that requires an argument, but the approach would remain the same (one coalescable callback executed on kernel entry). Kernel entry vs execution of the deferred operation =================================================== This is what I've referred to as the "Danger Zone" during my LPC24 talk [4]. There is a non-zero length of code that is executed upon kernel entry before the deferred operation can be itself executed (before we start getting into context_tracking.c proper), i.e.: idtentry_func_foo() <--- we're in the kernel irqentry_enter() enter_from_user_mode() __ct_user_exit() ct_kernel_enter_state() ct_work_flush() <--- deferred operation is executed here This means one must take extra care to what can happen in the early entry code, and that <bad things> cannot happen. For instance, we really don't want to hit instructions that have been modified by a remote text_poke() while we're on our way to execute a deferred sync_core(). Patches doing the actual deferral have more detail on this. Where are we at with this whole thing? ====================================== Dave has been incredibly helpful wrt figuring out what would and wouldn't (mostly that) be safe to do for deferring kernel range TLB flush IPIs, see [5]. Long story short, there are ugly things I can still do to (safely) defer the TLB flush IPIs, but it's going to be a long session of pulling my own hair out, and I got plenty so I won't be done for a while. In the meantime, I think everything leading up to deferring text poke IPIs is sane-ish and could get in. I'm not the biggest fan of adding an API with a single user, but hey, I've been working on this for "a little while" now and I'll still need to get the other IPIs sorted out. TL;DR: Text patching IPI deferral LGTM so here it is for now, I'm still working on the TLB flush thing. Patches ======= o Patches 1-2 are standalone objtool cleanups. o Patches 3-4 add an RCU testing feature. o Patches 5-6 add infrastructure for annotating static keys and static calls that may be used in noinstr code (courtesy of Josh). o Patches 7-20 use said annotations on relevant keys / calls. o Patch 21 enforces proper usage of said annotations (courtesy of Josh). o Patches 22-23 deal with detecting NOINSTR text in modules o Patches 24-25 add the actual IPI deferral faff Patches are also available at: https://gitlab.com/vschneid/linux.git -b redhat/isolirq/defer/v5 Testing ======= Xeon E5-2699 system with SMToff, NOHZ_FULL, isolated CPUs. RHEL10 userspace. Workload is using rteval (kernel compilation + hackbench) on housekeeping CPUs and a dummy stay-in-userspace loop on the isolated CPUs. The main invocation is: $ trace-cmd record -e "csd_queue_cpu" -f "cpu & CPUS{$ISOL_CPUS}" \ -e "ipi_send_cpumask" -f "cpumask & CPUS{$ISOL_CPUS}" \ -e "ipi_send_cpu" -f "cpu & CPUS{$ISOL_CPUS}" \ rteval --onlyload --loads-cpulist=$HK_CPUS \ --hackbench-runlowmem=True --duration=$DURATION This only records IPIs sent to isolated CPUs, so any event there is interference (with a bit of fuzz at the start/end of the workload when spawning the processes). All tests were done with a duration of 3 hours. v6.14 # This is the actual IPI count $ trace-cmd report | grep callback | awk '{ print $(NF) }' | sort | uniq -c | sort -nr 93 callback=generic_smp_call_function_single_interrupt+0x0 22 callback=nohz_full_kick_func+0x0 # These are the different CSD's that caused IPIs $ trace-cmd report | grep csd_queue | awk '{ print $(NF-1) }' | sort | uniq -c | sort -nr 1456 func=do_flush_tlb_all 78 func=do_sync_core 33 func=nohz_full_kick_func 26 func=do_kernel_range_flush v6.14 + patches # This is the actual IPI count $ trace-cmd report | grep callback | awk '{ print $(NF) }' | sort | uniq -c | sort -nr 86 callback=generic_smp_call_function_single_interrupt+0x0 41 callback=nohz_full_kick_func+0x0 # These are the different CSD's that caused IPIs $ trace-cmd report | grep csd_queue | awk '{ print $(NF-1) }' | sort | uniq -c | sort -nr 1378 func=do_flush_tlb_all 33 func=nohz_full_kick_func So the TLB flush is still there driving most of the IPIs, but at least the instruction patching IPIs are gone. With kernel TLB flushes deferred, there are no IPIs sent to isolated CPUs in that 3hr window, but as stated above that still needs some more work. Also note that tlb_remove_table_smp_sync() showed up during testing of v3, and has gone as mysteriously as it showed up. Yair had a series adressing this [6] which per these results would be worth revisiting. Acknowledgements ================ Special thanks to: o Clark Williams for listening to my ramblings about this and throwing ideas my way o Josh Poimboeuf for all his help with everything objtool-related o All of the folks who attended various (too many?) talks about this and provided precious feedback. o The mm folks for pointing out what I can and can't do with TLB flushes Links ===== [1]: https://lore.kernel.org/all/20210929151723.162004989@infradead.org/ [2]: https://github.com/vianpl/linux.git -b ct-work-defer-wip [3]: https://youtu.be/0vjE6fjoVVE [4]: https://lpc.events/event/18/contributions/1889/ [5]: http://lore.kernel.org/r/eef09bdc-7546-462b-9ac0-661a44d2ceae@intel.com [6]: https://lore.kernel.org/lkml/20230620144618.125703-1-ypodemsk@redhat.com/ Revisions ========= v4 -> v5 ++++++++ o Rebased onto v6.15-rc3 o Collected Reviewed-by o Annotated a few more static keys o Added proper checking of noinstr sections that are in loadable code such as KVM early entry (Sean Christopherson) o Switched to checking for CT_RCU_WATCHING instead of CT_STATE_KERNEL or CT_STATE_IDLE, which means deferral is now behaving sanely for IRQ/NMI entry from idle (thanks to Frederic!) o Ditched the vmap TLB flush deferral (for now) RFCv3 -> v4 +++++++++++ o Rebased onto v6.13-rc6 o New objtool patches from Josh o More .noinstr static key/call patches o Static calls now handled as well (again thanks to Josh) o Fixed clearing the work bits on kernel exit o Messed with IRQ hitting an idle CPU vs context tracking o Various comment and naming cleanups o Made RCU_DYNTICKS_TORTURE depend on !COMPILE_TEST (PeterZ) o Fixed the CT_STATE_KERNEL check when setting a deferred work (Frederic) o Cleaned up the __flush_tlb_all() mess thanks to PeterZ RFCv2 -> RFCv3 ++++++++++++++ o Rebased onto v6.12-rc6 o Added objtool documentation for the new warning (Josh) o Added low-size RCU watching counter to TREE04 torture scenario (Paul) o Added FORCEFUL jump label and static key types o Added noinstr-compliant helpers for tlb flush deferral RFCv1 -> RFCv2 ++++++++++++++ o Rebased onto v6.5-rc1 o Updated the trace filter patches (Steven) o Fixed __ro_after_init keys used in modules (Peter) o Dropped the extra context_tracking atomic, squashed the new bits in the existing .state field (Peter, Frederic) o Added an RCU_EXPERT config for the RCU dynticks counter size, and added an rcutorture case for a low-size counter (Paul) o Fixed flush_tlb_kernel_range_deferrable() definition Josh Poimboeuf (3): jump_label: Add annotations for validating noinstr usage static_call: Add read-only-after-init static calls objtool: Add noinstr validation for static branches/calls Valentin Schneider (22): objtool: Make validate_call() recognize indirect calls to pv_ops[] objtool: Flesh out warning related to pv_ops[] calls rcu: Add a small-width RCU watching counter debug option rcutorture: Make TREE04 use CONFIG_RCU_DYNTICKS_TORTURE x86/paravirt: Mark pv_sched_clock static call as __ro_after_init x86/idle: Mark x86_idle static call as __ro_after_init x86/paravirt: Mark pv_steal_clock static call as __ro_after_init riscv/paravirt: Mark pv_steal_clock static call as __ro_after_init loongarch/paravirt: Mark pv_steal_clock static call as __ro_after_init arm64/paravirt: Mark pv_steal_clock static call as __ro_after_init arm/paravirt: Mark pv_steal_clock static call as __ro_after_init perf/x86/amd: Mark perf_lopwr_cb static call as __ro_after_init sched/clock: Mark sched_clock_running key as __ro_after_init KVM: VMX: Mark __kvm_is_using_evmcs static key as __ro_after_init x86/speculation/mds: Mark mds_idle_clear key as allowed in .noinstr sched/clock, x86: Mark __sched_clock_stable key as allowed in .noinstr KVM: VMX: Mark vmx_l1d_should flush and vmx_l1d_flush_cond keys as allowed in .noinstr stackleack: Mark stack_erasing_bypass key as allowed in .noinstr module: Remove outdated comment about text_size module: Add MOD_NOINSTR_TEXT mem_type context-tracking: Introduce work deferral infrastructure context_tracking,x86: Defer kernel text patching IPIs arch/Kconfig | 9 ++ arch/arm/kernel/paravirt.c | 2 +- arch/arm64/kernel/paravirt.c | 2 +- arch/loongarch/kernel/paravirt.c | 2 +- arch/riscv/kernel/paravirt.c | 2 +- arch/x86/Kconfig | 1 + arch/x86/events/amd/brs.c | 2 +- arch/x86/include/asm/context_tracking_work.h | 18 +++ arch/x86/include/asm/text-patching.h | 1 + arch/x86/kernel/alternative.c | 39 ++++++- arch/x86/kernel/cpu/bugs.c | 2 +- arch/x86/kernel/kprobes/core.c | 4 +- arch/x86/kernel/kprobes/opt.c | 4 +- arch/x86/kernel/module.c | 2 +- arch/x86/kernel/paravirt.c | 4 +- arch/x86/kernel/process.c | 2 +- arch/x86/kvm/vmx/vmx.c | 11 +- arch/x86/kvm/vmx/vmx_onhyperv.c | 2 +- include/asm-generic/sections.h | 15 +++ include/linux/context_tracking.h | 21 ++++ include/linux/context_tracking_state.h | 54 +++++++-- include/linux/context_tracking_work.h | 26 +++++ include/linux/jump_label.h | 30 ++++- include/linux/module.h | 6 +- include/linux/objtool.h | 7 ++ include/linux/static_call.h | 19 ++++ kernel/context_tracking.c | 69 +++++++++++- kernel/kprobes.c | 8 +- kernel/module/main.c | 85 ++++++++++---- kernel/rcu/Kconfig.debug | 15 +++ kernel/sched/clock.c | 7 +- kernel/stackleak.c | 6 +- kernel/time/Kconfig | 5 + tools/objtool/Documentation/objtool.txt | 34 ++++++ tools/objtool/check.c | 106 +++++++++++++++--- tools/objtool/include/objtool/check.h | 1 + tools/objtool/include/objtool/elf.h | 1 + tools/objtool/include/objtool/special.h | 1 + tools/objtool/special.c | 15 ++- .../selftests/rcutorture/configs/rcu/TREE04 | 1 + 40 files changed, 557 insertions(+), 84 deletions(-) create mode 100644 arch/x86/include/asm/context_tracking_work.h create mode 100644 include/linux/context_tracking_work.h -- 2.49.0

3 months, 3 weeks

5
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[PATCH v3 00/32] kselftest harness and nolibc compatibility

by Thomas Weißschuh

Nolibc is useful for selftests as the test programs can be very small, and compiled with just a kernel crosscompiler, without userspace support. Currently nolibc is only usable with kselftest.h, not the more convenient to use kselftest_harness.h This series provides this compatibility by adding new features to nolibc and removing the usage of problematic features from the harness. The first half of the series are changes to the harness, the second one are for nolibc. Both parts are very independent and should go through different trees. The last patch is not meant to be applied and serves as test that everything works together correctly. Signed-off-by: Thomas Weißschuh <thomas.weissschuh(a)linutronix.de> --- Changes in v3: - Send patches to correct kselftest harness maintainers - Move harness selftest to dedicated directory - Add harness selftest to MAINTAINERS - Integrate harness selftest cleanup with the selftest framework - Consistently use "kselftest harness" in commit messages - Properly propagate kselftest harness failure - Link to v2: https://lore.kernel.org/r/20250407-nolibc-kselftest-harness-v2-0-f8812f76e9… Changes in v2: - Rebase unto v6.15-rc1 - Rename internal nolibc symbols - Handle edge case of waitpid(INT_MIN) == ESRCH - Fix arm configurations for final testing patch - Clean up global getopt.h variable declarations - Add Acks from Willy - Link to v1: https://lore.kernel.org/r/20250304-nolibc-kselftest-harness-v1-0-adca7cd231… --- Thomas Weißschuh (32): selftests: harness: Add kselftest harness selftest selftests: harness: Use C89 comment style selftests: harness: Ignore unused variant argument warning selftests: harness: Mark functions without prototypes static selftests: harness: Remove inline qualifier for wrappers selftests: harness: Remove dependency on libatomic selftests: harness: Implement test timeouts through pidfd selftests: harness: Don't set setup_completed for fixtureless tests selftests: harness: Always provide "self" and "variant" selftests: harness: Move teardown conditional into test metadata selftests: harness: Add teardown callback to test metadata selftests: harness: Stop using setjmp()/longjmp() selftests: harness: Guard includes on nolibc tools/nolibc: handle intmax_t/uintmax_t in printf tools/nolibc: use intmax definitions from compiler tools/nolibc: use pselect6_time64 if available tools/nolibc: use ppoll_time64 if available tools/nolibc: add tolower() and toupper() tools/nolibc: add _exit() tools/nolibc: add setpgrp() tools/nolibc: implement waitpid() in terms of waitid() Revert "selftests/nolibc: use waitid() over waitpid()" tools/nolibc: add dprintf() and vdprintf() tools/nolibc: add getopt() tools/nolibc: allow different write callbacks in printf tools/nolibc: allow limiting of printf destination size tools/nolibc: add snprintf() and friends selftests/nolibc: use snprintf() for printf tests selftests/nolibc: rename vfprintf test suite selftests/nolibc: add test for snprintf() truncation tools/nolibc: implement width padding in printf() HACK: selftests/nolibc: demonstrate usage of the kselftest harness MAINTAINERS | 1 + tools/include/nolibc/Makefile | 1 + tools/include/nolibc/getopt.h | 101 ++ tools/include/nolibc/nolibc.h | 1 + tools/include/nolibc/stdint.h | 4 +- tools/include/nolibc/stdio.h | 127 +- tools/include/nolibc/string.h | 17 + tools/include/nolibc/sys.h | 105 +- tools/testing/selftests/Makefile | 1 + tools/testing/selftests/kselftest_harness.h | 181 +- .../testing/selftests/kselftest_harness/.gitignore | 2 + tools/testing/selftests/kselftest_harness/Makefile | 7 + .../selftests/kselftest_harness/harness-selftest.c | 129 ++ .../kselftest_harness/harness-selftest.expected | 62 + .../kselftest_harness/harness-selftest.sh | 13 + tools/testing/selftests/nolibc/Makefile | 13 +- tools/testing/selftests/nolibc/harness-selftest.c | 1 + tools/testing/selftests/nolibc/nolibc-test.c | 1729 +------------------- tools/testing/selftests/nolibc/run-tests.sh | 2 +- 19 files changed, 637 insertions(+), 1860 deletions(-) --- base-commit: 0af2f6be1b4281385b618cb86ad946eded089ac8 change-id: 20250130-nolibc-kselftest-harness-8b2c8cac43bf Best regards, -- Thomas Weißschuh <thomas.weissschuh(a)linutronix.de>

3 months, 3 weeks

7
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[PATCH v13 net-next 0/5] DUALPI2 patch

by chia-yu.chang＠nokia-bell-labs.com

From: Chia-Yu Chang <chia-yu.chang(a)nokia-bell-labs.com> Hello, Please find the DualPI2 patch v13. v13 (26-Apr-2025) - Use dashes in member names to follow YNL conventions in tc.yaml (Donald Hunter <donald.hunter(a)gmail.com>) - Define enumerations separately for flags of drop-early, drop-overload, ecn-mask, credit-queue in tc.yaml (Donald Hunter <donald.hunter(a)gmail.com>) - Change the types of split-gso and step-packets into flag in tc.yaml (Donald Hunter <donald.hunter(a)gmail.com>) - Revert to u32/u8 types for tc-dualpi2-xstats members in tc.yaml (Donald Hunter <donald.hunter(a)gmail.com>) - Add new test cases in tc-tests/qdiscs/dualpi2.json to cover all dualpi2 paramters (Donald Hunter <donald.hunter(a)gmail.com>) - Change the type of TCA_DUALPI2_STEP_PACKETS into NLA_FLAG (Donald Hunter <donald.hunter(a)gmail.com>) v12 (22-Apr-2025) - Remove anonymous struct in sch_dualpi2.c (Paolo Abeni <pabeni(a)redhat.com>) - Replace u32/u8 with uint and s32 with int in tc spec document (Paolo Abeni <pabeni(a)redhat.com>) - Introduce get_memory_limit function to handle potential overflow when multipling limit with MTU (Paolo Abeni <pabeni(a)redhat.com>) - Double the packet length to further include packet overhead in memory_limit (Paolo Abeni <pabeni(a)redhat.com>) - Remove the check of qdisc_qlen(sch) when calling qdisc_tree_reduce_backlog (Paolo Abeni <pabeni(a)redhat.com>) v11 (15-Apr-2025) - Replace hstimer_init with hstimer_setup in sch_dualpi2.c v10 (25-Mar-2025) - Remove leftover include in include/linux/netdevice.h and anonymous struct in sch_dualpi2.c (Paolo Abeni <pabeni(a)redhat.com>) - Use kfree_skb_reason() and add SKB_DROP_REASON_DUALPI2_STEP_DROP drop reason (Paolo Abeni <pabeni(a)redhat.com>) - Split sch_dualpi2.c into 3 patches (and overall 5 patches): Struct definition & parsing, Dump stats & configuration, Enqueue/Dequeue (Paolo Abeni <pabeni(a)redhat.com>) v9 (16-Mar-2025) - Fix mem_usage error in previous version - Add min_qlen_step to the dualpi2 attribute as the minimum queue length in number of packets in the L-queue to start step threshold marking. In previous versions, this value was fixed to 2, so the step threshold was applied to mark packets in the L queue only when the queue length of the L queue was greater than or equal to 2 packets. This will cause larger queuing delays for L4S traffic at low rates (<20Mbps). So we parameterize it and change the default value to 0. Comparison of tcp_1down run 'HTB 20Mbit + DUALPI2 + 10ms base delay' Old versions: avg median # data pts Ping (ms) ICMP : 11.55 11.70 ms 350 TCP upload avg : 18.96 N/A Mbits/s 350 TCP upload sum : 18.96 N/A Mbits/s 350 New version (v9): avg median # data pts Ping (ms) ICMP : 10.81 10.70 ms 350 TCP upload avg : 18.91 N/A Mbits/s 350 TCP upload sum : 18.91 N/A Mbits/s 350 Comparison of tcp_1down run 'HTB 10Mbit + DUALPI2 + 10ms base delay' Old versions: avg median # data pts Ping (ms) ICMP : 12.61 12.80 ms 350 TCP upload avg : 9.48 N/A Mbits/s 350 TCP upload sum : 9.48 N/A Mbits/s 350 New version (v9): avg median # data pts Ping (ms) ICMP : 11.06 10.80 ms 350 TCP upload avg : 9.43 N/A Mbits/s 350 TCP upload sum : 9.43 N/A Mbits/s 350 Comparison of tcp_1down run 'HTB 10Mbit + DUALPI2 + 10ms base delay' Old versions: avg median # data pts Ping (ms) ICMP : 40.86 37.45 ms 350 TCP upload avg : 0.88 N/A Mbits/s 350 TCP upload sum : 0.88 N/A Mbits/s 350 TCP upload::1 : 0.88 0.97 Mbits/s 350 New version (v9): avg median # data pts Ping (ms) ICMP : 11.07 10.40 ms 350 TCP upload avg : 0.55 N/A Mbits/s 350 TCP upload sum : 0.55 N/A Mbits/s 350 TCP upload::1 : 0.55 0.59 Mbits/s 350 v8 (11-Mar-2025) - Fix warning messages in v7 v7 (07-Mar-2025) - Separate into 3 patches to avoid mixing changes of documentation, selftest, and code. (Cong Wang <xiyou.wangcong(a)gmail.com>) v6 (04-Mar-2025) - Add modprobe for dulapi2 in tc-testing script tc-testing/tdc.sh (Jakub Kicinski <kuba(a)kernel.org>) - Update test cases in dualpi2.json - Update commit message v5 (22-Feb-2025) - A comparison was done between MQ + DUALPI2, MQ + FQ_PIE, MQ + FQ_CODEL: Unshaped 1gigE with 4 download streams test: - Summary of tcp_4down run 'MQ + FQ_CODEL': avg median # data pts Ping (ms) ICMP : 1.19 1.34 ms 349 TCP download avg : 235.42 N/A Mbits/s 349 TCP download sum : 941.68 N/A Mbits/s 349 TCP download::1 : 235.19 235.39 Mbits/s 349 TCP download::2 : 235.03 235.35 Mbits/s 349 TCP download::3 : 236.89 235.44 Mbits/s 349 TCP download::4 : 234.57 235.19 Mbits/s 349 - Summary of tcp_4down run 'MQ + FQ_PIE' avg median # data pts Ping (ms) ICMP : 1.21 1.37 ms 350 TCP download avg : 235.42 N/A Mbits/s 350 TCP download sum : 941.61 N/A Mbits/s 350 TCP download::1 : 232.54 233.13 Mbits/s 350 TCP download::2 : 232.52 232.80 Mbits/s 350 TCP download::3 : 233.14 233.78 Mbits/s 350 TCP download::4 : 243.41 241.48 Mbits/s 350 - Summary of tcp_4down run 'MQ + DUALPI2' avg median # data pts Ping (ms) ICMP : 1.19 1.34 ms 349 TCP download avg : 235.42 N/A Mbits/s 349 TCP download sum : 941.68 N/A Mbits/s 349 TCP download::1 : 235.19 235.39 Mbits/s 349 TCP download::2 : 235.03 235.35 Mbits/s 349 TCP download::3 : 236.89 235.44 Mbits/s 349 TCP download::4 : 234.57 235.19 Mbits/s 349 Unshaped 1gigE with 128 download streams test: - Summary of tcp_128down run 'MQ + FQ_CODEL': avg median # data pts Ping (ms) ICMP : 1.88 1.86 ms 350 TCP download avg : 7.39 N/A Mbits/s 350 TCP download sum : 946.47 N/A Mbits/s 350 - Summary of tcp_128down run 'MQ + FQ_PIE': avg median # data pts Ping (ms) ICMP : 1.88 1.86 ms 350 TCP download avg : 7.39 N/A Mbits/s 350 TCP download sum : 946.47 N/A Mbits/s 350 - Summary of tcp_128down run 'MQ + DUALPI2': avg median # data pts Ping (ms) ICMP : 1.88 1.86 ms 350 TCP download avg : 7.39 N/A Mbits/s 350 TCP download sum : 946.47 N/A Mbits/s 350 Unshaped 10gigE with 4 download streams test: - Summary of tcp_4down run 'MQ + FQ_CODEL': avg median # data pts Ping (ms) ICMP : 0.22 0.23 ms 350 TCP download avg : 2354.08 N/A Mbits/s 350 TCP download sum : 9416.31 N/A Mbits/s 350 TCP download::1 : 2353.65 2352.81 Mbits/s 350 TCP download::2 : 2354.54 2354.21 Mbits/s 350 TCP download::3 : 2353.56 2353.78 Mbits/s 350 TCP download::4 : 2354.56 2354.45 Mbits/s 350 - Summary of tcp_4down run 'MQ + FQ_PIE': avg median # data pts Ping (ms) ICMP : 0.20 0.19 ms 350 TCP download avg : 2354.76 N/A Mbits/s 350 TCP download sum : 9419.04 N/A Mbits/s 350 TCP download::1 : 2354.77 2353.89 Mbits/s 350 TCP download::2 : 2353.41 2354.29 Mbits/s 350 TCP download::3 : 2356.18 2354.19 Mbits/s 350 TCP download::4 : 2354.68 2353.15 Mbits/s 350 - Summary of tcp_4down run 'MQ + DUALPI2': avg median # data pts Ping (ms) ICMP : 0.24 0.24 ms 350 TCP download avg : 2354.11 N/A Mbits/s 350 TCP download sum : 9416.43 N/A Mbits/s 350 TCP download::1 : 2354.75 2353.93 Mbits/s 350 TCP download::2 : 2353.15 2353.75 Mbits/s 350 TCP download::3 : 2353.49 2353.72 Mbits/s 350 TCP download::4 : 2355.04 2353.73 Mbits/s 350 Unshaped 10gigE with 128 download streams test: - Summary of tcp_128down run 'MQ + FQ_CODEL': avg median # data pts Ping (ms) ICMP : 7.57 8.69 ms 350 TCP download avg : 73.97 N/A Mbits/s 350 TCP download sum : 9467.82 N/A Mbits/s 350 - Summary of tcp_128down run 'MQ + FQ_PIE': avg median # data pts Ping (ms) ICMP : 7.82 8.91 ms 350 TCP download avg : 73.97 N/A Mbits/s 350 TCP download sum : 9468.42 N/A Mbits/s 350 - Summary of tcp_128down run 'MQ + DUALPI2': avg median # data pts Ping (ms) ICMP : 6.87 7.93 ms 350 TCP download avg : 73.95 N/A Mbits/s 350 TCP download sum : 9465.87 N/A Mbits/s 350 From the results shown above, we see small differences between combinations. - Update commit message to include results of no_split_gso and split_gso (Dave Taht <dave.taht(a)gmail.com> and Paolo Abeni <pabeni(a)redhat.com>) - Add memlimit in the dualpi2 attribute, and add memory_used, max_memory_used, memory_limit in dualpi2 stats (Dave Taht <dave.taht(a)gmail.com>) - Update note in sch_dualpi2.c related to BBRv3 status (Dave Taht <dave.taht(a)gmail.com>) - Update license identifier (Dave Taht <dave.taht(a)gmail.com>) - Add selftest in tools/testing/selftests/tc-testing (Cong Wang <xiyou.wangcong(a)gmail.com>) - Use netlink policies for parameter checks (Jamal Hadi Salim <jhs(a)mojatatu.com>) - Modify texts & fix typos in Documentation/netlink/specs/tc.yaml (Dave Taht <dave.taht(a)gmail.com>) - Add descriptions of packet counter statistics and the reset function of sch_dualpi2.c - Fix step_thresh in packets - Update code comments in sch_dualpi2.c v4 (22-Oct-2024) - Update statement in Kconfig for DualPI2 (Stephen Hemminger <stephen(a)networkplumber.org>) - Put a blank line after #define in sch_dualpi2.c (Stephen Hemminger <stephen(a)networkplumber.org>) - Fix line length warning. v3 (19-Oct-2024) - Fix compilaiton error - Update Documentation/netlink/specs/tc.yaml (Jakub Kicinski <kuba(a)kernel.org>) v2 (18-Oct-2024) - Add Documentation/netlink/specs/tc.yaml (Jakub Kicinski <kuba(a)kernel.org>) - Use dualpi2 instead of skb prefix (Jamal Hadi Salim <jhs(a)mojatatu.com>) - Replace nla_parse_nested_deprecated with nla_parse_nested (Jamal Hadi Salim <jhs(a)mojatatu.com>) - Fix line length warning For more details of DualPI2, please refer IETF RFC9332 (https://datatracker.ietf.org/doc/html/rfc9332). Best regards, Chia-Yu Chia-Yu Chang (4): Documentation: netlink: specs: tc: Add DualPI2 specification selftests/tc-testing: Add selftests for qdisc DualPI2 sched: Struct definition and parsing of dualpi2 qdisc sched: Dump configuration and statistics of dualpi2 qdisc Koen De Schepper (1): sched: Add enqueue/dequeue of dualpi2 qdisc Documentation/netlink/specs/tc.yaml | 166 +++ include/net/dropreason-core.h | 6 + include/uapi/linux/pkt_sched.h | 39 + net/sched/Kconfig | 12 + net/sched/Makefile | 1 + net/sched/sch_dualpi2.c | 1089 +++++++++++++++++ tools/testing/selftests/tc-testing/config | 1 + .../tc-testing/tc-tests/qdiscs/dualpi2.json | 254 ++++ tools/testing/selftests/tc-testing/tdc.sh | 1 + 9 files changed, 1569 insertions(+) create mode 100644 net/sched/sch_dualpi2.c create mode 100644 tools/testing/selftests/tc-testing/tc-tests/qdiscs/dualpi2.json -- 2.34.1

3 months, 3 weeks

3
9
0 0

[PATCH bpf-next v1 0/2] ktls, sockmap: Fix missing uncharge operation and add selfttest

by Jiayuan Chen

Cong reported a warning when running ./test_sockmp: https://lore.kernel.org/bpf/aAmIi0vlycHtbXeb@pop-os.localdomain/T/#t ------------[ cut here ]------------ WARNING: CPU: 1 PID: 40 at net/ipv4/af_inet.c inet_sock_destruct+0x173/0x1d5 Tainted: [W]=WARN Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014 Workqueue: events sk_psock_destroy RIP: 0010:inet_sock_destruct+0x173/0x1d5 RSP: 0018:ffff8880085cfc18 EFLAGS: 00010202 RAX: 1ffff11003dbfc00 RBX: ffff88801edfe3e8 RCX: ffffffff822f5af4 RDX: 0000000000000007 RSI: dffffc0000000000 RDI: ffff88801edfe16c RBP: ffff88801edfe184 R08: ffffed1003dbfc31 R09: 0000000000000000 R10: ffffffff822f5ab7 R11: ffff88801edfe187 R12: ffff88801edfdec0 R13: ffff888020376ac0 R14: ffff888020376ac0 R15: ffff888020376a60 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000556365155830 CR3: 000000001d6aa000 CR4: 0000000000350ef0 Call Trace: <TASK> __sk_destruct+0x46/0x222 sk_psock_destroy+0x22f/0x242 process_one_work+0x504/0x8a8 ? process_one_work+0x39d/0x8a8 ? __pfx_process_one_work+0x10/0x10 ? worker_thread+0x44/0x2ae ? __list_add_valid_or_report+0x83/0xea ? srso_return_thunk+0x5/0x5f ? __list_add+0x45/0x52 process_scheduled_works+0x73/0x82 worker_thread+0x1ce/0x2ae When we specify apply_bytes, we divide the msg into multiple segments, each with a length of 'send', and every time we send this part of the data using tcp_bpf_sendmsg_redir(), we use sk_msg_return_zero() to uncharge the memory of the specified 'send' size. However, if the first segment of data fails to send, for example, the peer's buffer is full, we need to release all of the msg. When releasing the msg, we haven't uncharged the memory of the subsequent segments. This modification does not make significant logical changes, but only fills in the missing uncharge places. This issue has existed all along, until it was exposed after we added the apply test in test_sockmap: commit 3448ad23b34e ("selftests/bpf: Add apply_bytes test to test_txmsg_redir_wait_sndmem in test_sockmap") Jiayuan Chen (2): ktls, sockmap: Fix missing uncharge operation selftests/bpf: Add test to cover sockmap with ktls net/tls/tls_sw.c | 7 ++ .../selftests/bpf/prog_tests/sockmap_ktls.c | 76 +++++++++++++++++++ .../selftests/bpf/progs/test_sockmap_ktls.c | 10 +++ 3 files changed, 93 insertions(+) -- 2.47.1

3 months, 3 weeks

3
6
0 0

[PATCH net-next v2] selftests: net: exit cleanly on SIGTERM / timeout

by Jakub Kicinski

ksft runner sends 2 SIGTERMs in a row if a test runs out of time. Handle this in a similar way we handle SIGINT - cleanup and stop running further tests. Because we get 2 signals we need a bit of logic to ignore the subsequent one, they come immediately one after the other (due to commit 9616cb34b08e ("kselftest/runner.sh: Propagate SIGTERM to runner child")). This change makes sure we run cleanup (scheduled defer()s) and also print a stack trace on SIGTERM, which doesn't happen by default. Tests occasionally hang in NIPA and it's impossible to tell what they are waiting from or doing. Signed-off-by: Jakub Kicinski <kuba(a)kernel.org> --- v2: - remove declaration at the global scope v1: https://lore.kernel.org/20250425151757.1652517-1-kuba@kernel.org CC: petrm(a)nvidia.com CC: willemb(a)google.com CC: sdf(a)fomichev.me CC: linux-kselftest(a)vger.kernel.org --- tools/testing/selftests/net/lib/py/ksft.py | 25 +++++++++++++++++++++- 1 file changed, 24 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/net/lib/py/ksft.py b/tools/testing/selftests/net/lib/py/ksft.py index 3cfad0fd4570..1b815768bf8a 100644 --- a/tools/testing/selftests/net/lib/py/ksft.py +++ b/tools/testing/selftests/net/lib/py/ksft.py @@ -3,6 +3,7 @@ import builtins import functools import inspect +import signal import sys import time import traceback @@ -26,6 +27,10 @@ KSFT_DISRUPTIVE = True pass +class KsftTerminate(KeyboardInterrupt): + pass + + def ksft_pr(*objs, **kwargs): print("#", *objs, **kwargs) @@ -193,6 +198,17 @@ KSFT_DISRUPTIVE = True return env +def _ksft_intr(signum, frame): + # ksft runner.sh sends 2 SIGTERMs in a row on a timeout + # if we don't ignore the second one it will stop us from handling cleanup + global term_cnt + term_cnt += 1 + if term_cnt == 1: + raise KsftTerminate() + else: + ksft_pr(f"Ignoring SIGTERM (cnt: {term_cnt}), already exiting...") + + def ksft_run(cases=None, globs=None, case_pfx=None, args=()): cases = cases or [] @@ -205,6 +221,10 @@ KSFT_DISRUPTIVE = True cases.append(value) break + global term_cnt + term_cnt = 0 + prev_sigterm = signal.signal(signal.SIGTERM, _ksft_intr) + totals = {"pass": 0, "fail": 0, "skip": 0, "xfail": 0} print("TAP version 13") @@ -229,11 +249,12 @@ KSFT_DISRUPTIVE = True cnt_key = 'xfail' except BaseException as e: stop |= isinstance(e, KeyboardInterrupt) + stop |= isinstance(e, KsftTerminate) tb = traceback.format_exc() for line in tb.strip().split('\n'): ksft_pr("Exception|", line) if stop: - ksft_pr("Stopping tests due to KeyboardInterrupt.") + ksft_pr(f"Stopping tests due to {type(e).__name__}.") KSFT_RESULT = False cnt_key = 'fail' @@ -248,6 +269,8 @@ KSFT_DISRUPTIVE = True if stop: break + signal.signal(signal.SIGTERM, prev_sigterm) + print( f"# Totals: pass:{totals['pass']} fail:{totals['fail']} xfail:{totals['xfail']} xpass:0 skip:{totals['skip']} error:0" ) -- 2.49.0

3 months, 3 weeks

4
4
0 0

[PATCH net-next v2] selftests: drv-net: rss_input_xfrm: Check test prerequisites before running

by Gal Pressman

Ensure the following prerequisites before executing the test: 1. 'socat' is installed on the remote host. 2. Python version supports socket.SO_INCOMING_CPU (available since v3.11). Skip the test if either prerequisite is not met. Reviewed-by: Nimrod Oren <noren(a)nvidia.com> Signed-off-by: Gal Pressman <gal(a)nvidia.com> --- Changelog - v1->v2: https://lore.kernel.org/netdev/20250317123149.364565-1-gal@nvidia.com/ * Use require_cmd() helper (Jakub). --- tools/testing/selftests/drivers/net/hw/rss_input_xfrm.py | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/tools/testing/selftests/drivers/net/hw/rss_input_xfrm.py b/tools/testing/selftests/drivers/net/hw/rss_input_xfrm.py index 53bb08cc29ec..f439c434ba36 100755 --- a/tools/testing/selftests/drivers/net/hw/rss_input_xfrm.py +++ b/tools/testing/selftests/drivers/net/hw/rss_input_xfrm.py @@ -32,6 +32,11 @@ def test_rss_input_xfrm(cfg, ipver): if multiprocessing.cpu_count() < 2: raise KsftSkipEx("Need at least two CPUs to test symmetric RSS hash") + cfg.require_cmd("socat", remote=True) + + if not hasattr(socket, "SO_INCOMING_CPU"): + raise KsftSkipEx("socket.SO_INCOMING_CPU was added in Python 3.11") + input_xfrm = cfg.ethnl.rss_get( {'header': {'dev-name': cfg.ifname}}).get('input_xfrm') -- 2.40.1

3 months, 3 weeks

2
1
0 0

[PATCH v5 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. 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/lkml/20250428181218.85925-1-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(-) -- 2.48.1

3 months, 4 weeks

2
11
0 0

[PATCH bpf-next v3 0/2] bpf: Allow XDP_REDIRECT for XDP dev-bound programs

by Lorenzo Bianconi

In the current implementation if the program is dev-bound to a specific device, it will not be possible to perform XDP_REDIRECT into a DEVMAP or CPUMAP even if the program is running in the driver NAPI context. Fix the issue introducing __bpf_prog_map_compatible utility routine in order to avoid bpf_prog_is_dev_bound() during the XDP program load. Continue forbidding to attach a dev-bound program to XDP maps. --- Changes in v3: - move seltest changes in a dedicated patch - Link to v2: https://lore.kernel.org/r/20250423-xdp-prog-bound-fix-v2-1-51742a5dfbce@ker… Changes in v2: - Introduce __bpf_prog_map_compatible() utility routine in order to skip bpf_prog_is_dev_bound check in bpf_check_tail_call() - Extend xdp_metadata selftest - Link to v1: https://lore.kernel.org/r/20250422-xdp-prog-bound-fix-v1-1-0b581fa186fe@ker… --- Lorenzo Bianconi (2): bpf: Allow XDP dev-bound programs to perform XDP_REDIRECT into maps selftests/bpf: xdp_metadata: check XDP_REDIRCT support for dev-bound progs kernel/bpf/core.c | 27 +++++++++++++--------- .../selftests/bpf/prog_tests/xdp_metadata.c | 22 +++++++++++++++++- tools/testing/selftests/bpf/progs/xdp_metadata.c | 13 +++++++++++ 3 files changed, 50 insertions(+), 12 deletions(-) --- base-commit: 91dbac4076537b464639953c055c460d2bdfc7ea change-id: 20250422-xdp-prog-bound-fix-9f30f3e134aa Best regards, -- Lorenzo Bianconi <lorenzo(a)kernel.org>

3 months, 4 weeks

2
3
0 0

[PATCH 0/5] riscv: misaligned: fix interruptible context and add tests

by Clément Léger

This series fixes misaligned access handling when in non interruptible context by reenabling interrupts when possible. A previous commit changed raw_copy_from_user() with copy_from_user() which enables page faulting and thus can sleep. While correct, a warning is now triggered due to being called in an invalid context (sleeping in non-interruptible). This series fixes that problem by factorizing misaligned load/store entry in a single function than reenables interrupt if the interrupted context had interrupts enabled. In order for misaligned handling problems to be caught sooner, add a kselftest for all the currently supported instructions . Note: these commits were actually part of another larger series for misaligned request delegation but was split since it isn't directly required. Clément Léger (5): riscv: misaligned: factorize trap handling riscv: misaligned: enable IRQs while handling misaligned accesses riscv: misaligned: use get_user() instead of __get_user() Documentation/sysctl: add riscv to unaligned-trap supported archs selftests: riscv: add misaligned access testing Documentation/admin-guide/sysctl/kernel.rst | 4 +- arch/riscv/kernel/traps.c | 57 ++-- arch/riscv/kernel/traps_misaligned.c | 2 +- .../selftests/riscv/misaligned/.gitignore | 1 + .../selftests/riscv/misaligned/Makefile | 12 + .../selftests/riscv/misaligned/common.S | 33 +++ .../testing/selftests/riscv/misaligned/fpu.S | 180 +++++++++++++ tools/testing/selftests/riscv/misaligned/gp.S | 103 +++++++ .../selftests/riscv/misaligned/misaligned.c | 254 ++++++++++++++++++ 9 files changed, 614 insertions(+), 32 deletions(-) create mode 100644 tools/testing/selftests/riscv/misaligned/.gitignore create mode 100644 tools/testing/selftests/riscv/misaligned/Makefile create mode 100644 tools/testing/selftests/riscv/misaligned/common.S create mode 100644 tools/testing/selftests/riscv/misaligned/fpu.S create mode 100644 tools/testing/selftests/riscv/misaligned/gp.S create mode 100644 tools/testing/selftests/riscv/misaligned/misaligned.c -- 2.49.0

3 months, 4 weeks

4
14
0 0

[PATCH v3 0/3] RISC-V KVM selftests improvements

by Atish Patra

This series improves the following tests. 1. Get-reg-list : Adds vector support 2. SBI PMU test : Distinguish between different types of illegal exception The first patch is just helper patch that adds stval support during exception handling. Signed-off-by: Atish Patra <atishp(a)rivosinc.com> --- Changes in v3: - Dropped the redundant macros and rv32 specific csr details. - Changed to vcpu_get_reg from __vcpu_get_reg based on suggestion from Drew. - Added RB tags from Drew. - Link to v2: https://lore.kernel.org/r/20250429-kvm_selftest_improve-v2-0-51713f91e04a@r… Changes in v2: - Rebased on top of Linux 6.15-rc4 - Changed from ex_regs to pt_regs based on Drew's suggestion. - Dropped Anup's review on PATCH1 as it is significantly changed from last review. - Moved the instruction decoding macros to a common header file. - Improved the vector reg list test as per the feedback. - Link to v1: https://lore.kernel.org/r/20250324-kvm_selftest_improve-v1-0-583620219d4f@r… --- Atish Patra (3): KVM: riscv: selftests: Align the trap information wiht pt_regs KVM: riscv: selftests: Decode stval to identify exact exception type KVM: riscv: selftests: Add vector extension tests .../selftests/kvm/include/riscv/processor.h | 23 +++- tools/testing/selftests/kvm/lib/riscv/handlers.S | 139 +++++++++++---------- tools/testing/selftests/kvm/lib/riscv/processor.c | 2 +- tools/testing/selftests/kvm/riscv/arch_timer.c | 2 +- tools/testing/selftests/kvm/riscv/ebreak_test.c | 2 +- tools/testing/selftests/kvm/riscv/get-reg-list.c | 132 +++++++++++++++++++ tools/testing/selftests/kvm/riscv/sbi_pmu_test.c | 24 +++- 7 files changed, 247 insertions(+), 77 deletions(-) --- base-commit: f15d97df5afae16f40ecef942031235d1c6ba14f change-id: 20250324-kvm_selftest_improve-9bedb9f0a6d3 -- Regards, Atish patra

3 months, 4 weeks

2
4
0 0

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