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

[PATCH] selftests/mm: compaction_test: Support platform with huge mount of memory

by Feng Tang

When running mm selftest to verify mm patches, 'compaction_test' case failed on an x86 server with 1TB memory. And the root cause is that it has too much free memory than what the test supports. The test case tries to allocate 100000 huge pages, which is about 200 GB for that x86 server, and when it succeeds, it expects it's large than 1/3 of 80% of the free memory in system. This logic only works for platform with 750 GB ( 200 / (1/3) / 80% ) or less free memory, and may raise false alarm for others. Fix it by changing the fixed page number to self-adjustable number according to the real number of free memory. Fixes: bd67d5c15cc19 ("Test compaction of mlocked memory") Signed-off-by: Feng Tang <feng.tang(a)linux.alibaba.com> --- tools/testing/selftests/mm/compaction_test.c | 19 ++++++++++++++----- 1 file changed, 14 insertions(+), 5 deletions(-) diff --git a/tools/testing/selftests/mm/compaction_test.c b/tools/testing/selftests/mm/compaction_test.c index 2c3a0eb6b22d..9bc4591c7b16 100644 --- a/tools/testing/selftests/mm/compaction_test.c +++ b/tools/testing/selftests/mm/compaction_test.c @@ -90,6 +90,8 @@ int check_compaction(unsigned long mem_free, unsigned long hugepage_size, int compaction_index = 0; char nr_hugepages[20] = {0}; char init_nr_hugepages[24] = {0}; + char target_nr_hugepages[24] = {0}; + int slen; snprintf(init_nr_hugepages, sizeof(init_nr_hugepages), "%lu", initial_nr_hugepages); @@ -106,11 +108,18 @@ int check_compaction(unsigned long mem_free, unsigned long hugepage_size, goto out; } - /* Request a large number of huge pages. The Kernel will allocate - as much as it can */ - if (write(fd, "100000", (6*sizeof(char))) != (6*sizeof(char))) { - ksft_print_msg("Failed to write 100000 to /proc/sys/vm/nr_hugepages: %s\n", - strerror(errno)); + /* + * Request huge pages for about half of the free memory. The Kernel + * will allocate as much as it can, and we expect it will get at least 1/3 + */ + nr_hugepages_ul = mem_free / hugepage_size / 2; + snprintf(target_nr_hugepages, sizeof(target_nr_hugepages), + "%lu", nr_hugepages_ul); + + slen = strlen(target_nr_hugepages); + if (write(fd, target_nr_hugepages, slen) != slen) { + ksft_print_msg("Failed to write %lu to /proc/sys/vm/nr_hugepages: %s\n", + nr_hugepages_ul, strerror(errno)); goto close_fd; } -- 2.43.5

1 day, 22 hours

3
3
0 0

[PATCH] selftests/pidfd: align stack to fix SP alignment exception

by Shuai Xue

The pidfd_test fails on the ARM64 platform with the following error: Bail out! pidfd_poll check for premature notification on child thread exec test: Failed When exception-trace is enabled, the kernel logs the details: #echo 1 > /proc/sys/debug/exception-trace #dmesg | tail -n 20 [48628.713023] pidfd_test[1082142]: unhandled exception: SP Alignment, ESR 0x000000009a000000, SP/PC alignment exception in pidfd_test[400000+4000] [48628.713049] CPU: 21 PID: 1082142 Comm: pidfd_test Kdump: loaded Tainted: G W E 6.6.71-3_rc1.al8.aarch64 #1 [48628.713051] Hardware name: AlibabaCloud AliServer-Xuanwu2.0AM-1UC1P-5B/AS1111MG1, BIOS 1.2.M1.AL.P.157.00 07/29/2023 [48628.713053] pstate: 60001800 (nZCv daif -PAN -UAO -TCO -DIT +SSBS BTYPE=-c) [48628.713055] pc : 0000000000402100 [48628.713056] lr : 0000ffff98288f9c [48628.713056] sp : 0000ffffde49daa8 [48628.713057] x29: 0000000000000000 x28: 0000000000000000 x27: 0000000000000000 [48628.713060] x26: 0000000000000000 x25: 0000000000000000 x24: 0000000000000000 [48628.713062] x23: 0000000000000000 x22: 0000000000000000 x21: 0000000000400e80 [48628.713065] x20: 0000000000000000 x19: 0000000000402650 x18: 0000000000000000 [48628.713067] x17: 00000000004200d8 x16: 0000ffff98288f40 x15: 0000ffffde49b92c [48628.713070] x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000 [48628.713072] x11: 0000000000001011 x10: 0000000000402100 x9 : 0000000000000010 [48628.713074] x8 : 00000000000000dc x7 : 3861616239346564 x6 : 000000000000000a [48628.713077] x5 : 0000ffffde49daa8 x4 : 000000000000000a x3 : 0000ffffde49daa8 [48628.713079] x2 : 0000ffffde49dadc x1 : 0000ffffde49daa8 x0 : 0000000000000000 According to ARM ARM D1.3.10.2 SP alignment checking: > When the SP is used as the base address of a calculation, regardless of > any offset applied by the instruction, if bits [3:0] of the SP are not > 0b0000, there is a misaligned SP. To fix it, align the stack with 16 bytes. Signed-off-by: Shuai Xue <xueshuai(a)linux.alibaba.com> --- tools/testing/selftests/pidfd/pidfd_test.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/testing/selftests/pidfd/pidfd_test.c b/tools/testing/selftests/pidfd/pidfd_test.c index c081ae91313a..ec161a7c3ff9 100644 --- a/tools/testing/selftests/pidfd/pidfd_test.c +++ b/tools/testing/selftests/pidfd/pidfd_test.c @@ -33,7 +33,7 @@ static bool have_pidfd_send_signal; static pid_t pidfd_clone(int flags, int *pidfd, int (*fn)(void *)) { size_t stack_size = 1024; - char *stack[1024] = { 0 }; + char *stack[1024] __attribute__((aligned(16))) = {0}; #ifdef __ia64__ return __clone2(fn, stack, stack_size, flags | SIGCHLD, NULL, pidfd); -- 2.39.3

1 day, 22 hours

2
4
0 0

[PATCH net-next v3 0/3] Fix netdevim to correctly mark NAPI IDs

by Joe Damato

Greetings: Welcome to v3. This series fixes netdevsim to correctly set the NAPI ID on the skb. This is helpful for writing tests around features that use SO_INCOMING_NAPI_ID. In addition to the netdevsim fix in patch 1, patches 2 & 3 do some self test refactoring and add a test for NAPI IDs. The test itself (patch 4) introduces a C helper because apparently python doesn't have socket.SO_INCOMING_NAPI_ID. Thanks, Joe v3: - Dropped patch 3 from v2 as it is no longer necessary. - Patch 3 from this series (which was patch 4 in the v2) - Sorted .gitignore alphabetically - added cfg.remote_deploy so the test supports real remote machines - Dropped the NetNSEnter as it is unnecessary - Fixed a string interpolation issue that Paolo hit with his Python version v2: https://lore.kernel.org/netdev/20250417013301.39228-1-jdamato@fastly.com/ - No longer an RFC - Minor whitespace change in patch 1 (no functional change). - Patches 2-4 new in v2 rfcv1: https://lore.kernel.org/netdev/20250329000030.39543-1-jdamato@fastly.com/ Joe Damato (3): netdevsim: Mark NAPI ID on skb in nsim_rcv selftests: drv-net: Factor out ksft C helpers selftests: drv-net: Test that NAPI ID is non-zero drivers/net/netdevsim/netdev.c | 2 + .../testing/selftests/drivers/net/.gitignore | 1 + tools/testing/selftests/drivers/net/Makefile | 6 +- tools/testing/selftests/drivers/net/ksft.h | 56 +++++++++++++ .../testing/selftests/drivers/net/napi_id.py | 24 ++++++ .../selftests/drivers/net/napi_id_helper.c | 83 +++++++++++++++++++ .../selftests/drivers/net/xdp_helper.c | 49 +---------- 7 files changed, 173 insertions(+), 48 deletions(-) create mode 100644 tools/testing/selftests/drivers/net/ksft.h create mode 100755 tools/testing/selftests/drivers/net/napi_id.py create mode 100644 tools/testing/selftests/drivers/net/napi_id_helper.c base-commit: 22ab6b9467c1822291a1175a0eb825b7ec057ef9 -- 2.43.0

2 days, 4 hours

2
6
0 0

[PATCH net 0/2] mptcp: pm: Defer freeing userspace pm entries

by Matthieu Baerts (NGI0)

Here are two unrelated fixes for MPTCP: - Patch 1: free userspace PM entry with RCU helpers. A fix for v6.14. - Patch 2: avoid a warning when running diag.sh selftest. A fix for v6.15-rc1. Signed-off-by: Matthieu Baerts (NGI0) <matttbe(a)kernel.org> --- Geliang Tang (1): selftests: mptcp: diag: use mptcp_lib_get_info_value Mat Martineau (1): mptcp: pm: Defer freeing of MPTCP userspace path manager entries net/mptcp/pm_userspace.c | 6 +++++- tools/testing/selftests/net/mptcp/diag.sh | 5 ++--- 2 files changed, 7 insertions(+), 4 deletions(-) --- base-commit: 750d0ac001e85b754404178ee8ce01cbc76a03be change-id: 20250421-net-mptcp-pm-defer-freeing-f9cd01b70043 Best regards, -- Matthieu Baerts (NGI0) <matttbe(a)kernel.org>

2 days, 4 hours

2
3
0 0

[PATCH bpf-next v1 0/2] bpf: Fix panic in bpf_get_local_storage

by Jiayuan Chen

The selftest I provided can reproduce a panic: './test_progs -a cgroup_storage_update' When we attach a program to cgroup and if prog->aux->cgroup_storage exists, which means the cgroup_storage map is used in the program, we will then allocate storage by bpf_cgroup_storages_alloc() and assign it to pl->storage. At the end, pl->storage will be assigned to cgrp->bpf.effective[atype]->cgroup_storage by xxx_effective_progs(). But when we attach a program without the cgroup_storage map being used (prog->aux->cgroup_storage is empty), the cgroup_storage in struct bpf_prog_array_item is empty. Then, if we use BPF_LINK_UPDATE to replace the old program with a new one that uses the cgroup_storage map, we miss the cgroup_storage being initialized. This causes a panic when accessing storage in bpf_get_local_storage. Jiayuan Chen (2): bpf: Create cgroup storage if needed when updating link selftests/bpf: Add link update test for cgroup_storage kernel/bpf/cgroup.c | 24 +++++++--- .../selftests/bpf/prog_tests/cgroup_storage.c | 45 +++++++++++++++++++ .../selftests/bpf/progs/cgroup_storage.c | 6 +++ 3 files changed, 70 insertions(+), 5 deletions(-) -- 2.47.1

2 days, 7 hours

3
6
0 0

[PATCH bpf-next v4 0/2] bpf: Allow access to const void pointer arguments in tracing programs

by KaFai Wan

If we try to access argument which is pointer to const void, it's an UNKNOWN type, verifier will fail to load. Use is_void_or_int_ptr to check if type is void or int pointer. Add a selftest to check it. --- KaFai Wan (2): bpf: Allow access to const void pointer arguments in tracing programs selftests/bpf: Add test to access const void pointer argument in tracing program kernel/bpf/btf.c | 13 +++---------- net/bpf/test_run.c | 8 +++++++- .../selftests/bpf/progs/verifier_btf_ctx_access.c | 12 ++++++++++++ 3 files changed, 22 insertions(+), 11 deletions(-) Changelog: v3->v4: Addressed comments from Alexei Starovoitov - change SOB to match From email address - add Acked-by from jirka Details in here: https://lore.kernel.org/all/20250417151548.1276279-1-kafai.wan@hotmail.com/ v2->v3: Addressed comments from jirka - remove duplicate checks for void pointer Details in here: https://lore.kernel.org/bpf/20250416161756.1079178-1-kafai.wan@hotmail.com/ v1->v2: Addressed comments from jirka - use btf_type_is_void to check if type is void - merge is_void_ptr and is_int_ptr to is_void_or_int_ptr - fix selftests Details in here: https://lore.kernel.org/all/20250412170626.3638516-1-kafai.wan@hotmail.com/ -- 2.43.0

2 days, 10 hours

3
4
0 0

[PATCH] selftests/bpf: Fix null pointer check in skb_pkt_end.c

by Prabhav Kumar Vaish

Ensure that 'tcp' is checked for NULL before dereferencing. This resolves a potential null pointer dereference warning reported by static analysis. Signed-off-by: Prabhav Kumar Vaish <pvkumar5749404(a)gmail.com> --- tools/testing/selftests/bpf/progs/skb_pkt_end.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/bpf/progs/skb_pkt_end.c b/tools/testing/selftests/bpf/progs/skb_pkt_end.c index 3bb4451524a1..db33ff2839f7 100644 --- a/tools/testing/selftests/bpf/progs/skb_pkt_end.c +++ b/tools/testing/selftests/bpf/progs/skb_pkt_end.c @@ -45,10 +45,10 @@ int main_prog(struct __sk_buff *skb) goto out; tcp = (void*)(ip + 1); - if (tcp->dest != 0) - goto out; if (!tcp) goto out; + if (tcp->dest != 0) + goto out; urg_ptr = tcp->urg_ptr; -- 2.34.1

2 days, 11 hours

2
2
0 0

[PATCH 0/4] Replace CONFIG_DMABUF_SYSFS_STATS with BPF

by T.J. Mercier

Until CONFIG_DMABUF_SYSFS_STATS was added [1] it was only possible to perform per-buffer accounting with debugfs which is not suitable for production environments. Eventually we discovered the overhead with per-buffer sysfs file creation/removal was significantly impacting allocation and free times, and exacerbated kernfs lock contention. [2] dma_buf_stats_setup() is responsible for 39% of single-page buffer creation duration, or 74% of single-page dma_buf_export() duration when stressing dmabuf allocations and frees. I prototyped a change from per-buffer to per-exporter statistics with a RCU protected list of exporter allocations that accommodates most (but not all) of our use-cases and avoids almost all of the sysfs overhead. While that adds less overhead than per-buffer sysfs, and less even than the maintenance of the dmabuf debugfs_list, it's still *additional* overhead on top of the debugfs_list and doesn't give us per-buffer info. This series uses the existing dmabuf debugfs_list to implement a BPF dmabuf iterator, which adds no overhead to buffer allocation/free and provides per-buffer info. While the kernel must have CONFIG_DEBUG_FS for the dmabuf_iter to be available, debugfs does not need to be mounted. The BPF program loaded by userspace that extracts per-buffer information gets to define its own interface which avoids the lack of ABI stability with debugfs (even if it were mounted). As this is a replacement for our use of CONFIG_DMABUF_SYSFS_STATS, the last patch is a RFC for removing it from the kernel. Please see my suggestion there regarding the timeline for that. [1] https://lore.kernel.org/linux-media/20201210044400.1080308-1-hridya@google.… [2] https://lore.kernel.org/all/20220516171315.2400578-1-tjmercier@google.com/ T.J. Mercier (4): dma-buf: Rename and expose debugfs symbols bpf: Add dmabuf iterator selftests/bpf: Add test for dmabuf_iter RFC: dma-buf: Remove DMA-BUF statistics .../ABI/testing/sysfs-kernel-dmabuf-buffers | 24 --- Documentation/driver-api/dma-buf.rst | 5 - drivers/dma-buf/Kconfig | 15 -- drivers/dma-buf/Makefile | 1 - drivers/dma-buf/dma-buf-sysfs-stats.c | 202 ------------------ drivers/dma-buf/dma-buf-sysfs-stats.h | 35 --- drivers/dma-buf/dma-buf.c | 40 +--- include/linux/btf_ids.h | 1 + include/linux/dma-buf.h | 6 + kernel/bpf/Makefile | 3 + kernel/bpf/dmabuf_iter.c | 130 +++++++++++ tools/testing/selftests/bpf/config | 1 + .../selftests/bpf/prog_tests/dmabuf_iter.c | 116 ++++++++++ .../testing/selftests/bpf/progs/dmabuf_iter.c | 31 +++ 14 files changed, 299 insertions(+), 311 deletions(-) delete mode 100644 Documentation/ABI/testing/sysfs-kernel-dmabuf-buffers delete mode 100644 drivers/dma-buf/dma-buf-sysfs-stats.c delete mode 100644 drivers/dma-buf/dma-buf-sysfs-stats.h create mode 100644 kernel/bpf/dmabuf_iter.c create mode 100644 tools/testing/selftests/bpf/prog_tests/dmabuf_iter.c create mode 100644 tools/testing/selftests/bpf/progs/dmabuf_iter.c -- 2.49.0.604.gff1f9ca942-goog

2 days, 11 hours

5
26
0 0

Re: [PATCH v7 1/2] selftests: memcg: Allow low event with no memory.low and memory_recursiveprot on

by Michal Koutný

On Tue, Apr 22, 2025 at 07:58:56PM -0400, Waiman Long <llong(a)redhat.com> wrote: > Am I correct to assume that the purpose of 1d09069f5313f ("selftests: > memcg: expect no low events in unprotected sibling") is to force a > failure in the test_memcg_low test to force a change in the current > behavior? Or was it the case that it didn't fail when you submit your > patch? Yes, the failure had been intended to mark unexpected mode of reclaim (there's still a reproducer somewhere in the references). However, I learnt that: a) it ain't easy to fix, b) the only occurence of the troublesome behavior was in the test and never reported by users in real life. I've started to prefer the variant where the particular check is indefinite since that. HTH, Michal

2 days, 11 hours

2
1
0 0

[PATCH v4 0/5] Add support for the Bus Lock Threshold

by Manali Shukla

Misbehaving guests can cause bus locks to degrade the performance of a system. Non-WB (write-back) and misaligned locked RMW (read-modify-write) instructions are referred to as "bus locks" and require system wide synchronization among all processors to guarantee the atomicity. The bus locks can impose notable performance penalties for all processors within the system. Support for the Bus Lock Threshold is indicated by CPUID Fn8000_000A_EDX[29] BusLockThreshold=1, the VMCB provides a Bus Lock Threshold enable bit and an unsigned 16-bit Bus Lock Threshold count. VMCB intercept bit VMCB Offset Bits Function 14h 5 Intercept bus lock operations Bus lock threshold count VMCB Offset Bits Function 120h 15:0 Bus lock counter During VMRUN, the bus lock threshold count is fetched and stored in an internal count register. Prior to executing a bus lock within the guest, the processor verifies the count in the bus lock register. If the count is greater than zero, the processor executes the bus lock, reducing the count. However, if the count is zero, the bus lock operation is not performed, and instead, a Bus Lock Threshold #VMEXIT is triggered to transfer control to the Virtual Machine Monitor (VMM). A Bus Lock Threshold #VMEXIT is reported to the VMM with VMEXIT code 0xA5h, VMEXIT_BUSLOCK. EXITINFO1 and EXITINFO2 are set to 0 on a VMEXIT_BUSLOCK. On a #VMEXIT, the processor writes the current value of the Bus Lock Threshold Counter to the VMCB. Note: Currently, virtualizing the Bus Lock Threshold feature for L1 guest is not supported. More details about the Bus Lock Threshold feature can be found in AMD APM [1]. v3 -> v4 - Incorporated Sean's review comments - Added a preparatory patch to move linear_rip out of kvm_pio_request, so that it can be used by the bus lock threshold patches. - Added complete_userspace_buslock() function to reload bus_lock_counter to '1' only if the usespace has not changed the RIP. - Added changes to continue running bus_lock_counter accross the nested transitions. v2 -> v3 - Drop parch to add virt tag in /proc/cpuinfo. - Incorporated Tom's review comments. v1 -> v2 - Incorporated misc review comments from Sean. - Removed bus_lock_counter module parameter. - Set the value of bus_lock_counter to zero by default and reload the value by 1 in bus lock exit handler. - Add documentation for the behavioral difference for KVM_EXIT_BUS_LOCK. - Improved selftest for buslock to work on SVM and VMX. - Rewrite the commit messages. Patches are prepared on kvm-next/next (c9ea48bb6ee6). Testing done: - Tested the Bus Lock Threshold functionality on normal, SEV, SEV-ES and SEV-SNP guests. - Tested the Bus Lock Threshold functionality on nested guests. v1: https://lore.kernel.org/kvm/20240709175145.9986-4-manali.shukla@amd.com/T/ v2: https://lore.kernel.org/kvm/20241001063413.687787-4-manali.shukla@amd.com/T/ v3: https://lore.kernel.org/kvm/20241004053341.5726-1-manali.shukla@amd.com/T/ [1]: AMD64 Architecture Programmer's Manual Pub. 24593, April 2024, Vol 2, 15.14.5 Bus Lock Threshold. https://bugzilla.kernel.org/attachment.cgi?id=306250 Manali Shukla (3): KVM: x86: Preparatory patch to move linear_rip out of kvm_pio_request x86/cpufeatures: Add CPUID feature bit for the Bus Lock Threshold KVM: SVM: Add support for KVM_CAP_X86_BUS_LOCK_EXIT on SVM CPUs Nikunj A Dadhania (2): KVM: SVM: Enable Bus lock threshold exit KVM: selftests: Add bus lock exit test Documentation/virt/kvm/api.rst | 19 +++ arch/x86/include/asm/cpufeatures.h | 1 + arch/x86/include/asm/kvm_host.h | 2 +- arch/x86/include/asm/svm.h | 5 +- arch/x86/include/uapi/asm/svm.h | 2 + arch/x86/kvm/svm/nested.c | 42 ++++++ arch/x86/kvm/svm/svm.c | 38 +++++ arch/x86/kvm/svm/svm.h | 2 + arch/x86/kvm/x86.c | 8 +- tools/testing/selftests/kvm/Makefile.kvm | 1 + .../selftests/kvm/x86/kvm_buslock_test.c | 135 ++++++++++++++++++ 11 files changed, 249 insertions(+), 6 deletions(-) create mode 100644 tools/testing/selftests/kvm/x86/kvm_buslock_test.c base-commit: c9ea48bb6ee6b28bbc956c1e8af98044618fed5e -- 2.34.1

2 days, 13 hours

4
18
0 0

2025

2024

2023

2022

2021

2020

2019

2018

2017

Linux-kselftest-mirror