RFR: 8366854: Extend jtreg failure handler with THP info

Stefan Karlsson stefank at openjdk.org
Thu Sep 4 07:11:36 UTC 2025


On Thu, 4 Sep 2025 07:03:01 GMT, Stefan Karlsson <stefank at openjdk.org> wrote:

> I propose that we also dump /proc/meminfo, /proc/vmstat, and /sys/kernel/mm/transparent_hugepage/{enabled, defrag} from the failure handler.
> 
> This information has been helpful when investigating a failure where there was an unexpected lack of transparent huge pages.

The proposed changes give the following output the environment.html file:

    * [proc_meminfo](file:///Users/stefank/environment.html#linux.memory.proc_meminfo)

    ----------------------------------------
    [2025-09-02 17:03:04] [/usr/bin/bash, -c, cat /proc/meminfo] timeout=20000 in /home/stefank/git/jdk/build/fastdebug/test-support/jtreg_open_test_hotspot_jtreg_gc_g1_TestPLABOutput_java/gc/g1/TestPLABOutput
    ----------------------------------------
    MemTotal:       64203564 kB
    MemFree:        28834780 kB
    MemAvailable:   61539920 kB
    Buffers:         1414464 kB
    Cached:         29551908 kB
    SwapCached:            0 kB
    Active:          4403292 kB
    Inactive:       27055328 kB
    Active(anon):     534448 kB
    Inactive(anon):        0 kB
    Active(file):    3868844 kB
    Inactive(file): 27055328 kB
    Unevictable:       21916 kB
    Mlocked:           21916 kB
    SwapTotal:       2097148 kB
    SwapFree:        2097148 kB
    Zswap:                 0 kB
    Zswapped:              0 kB
    Dirty:               228 kB
    Writeback:             0 kB
    AnonPages:        514180 kB
    Mapped:           394392 kB
    Shmem:             30936 kB
    KReclaimable:    2503268 kB
    Slab:            3214280 kB
    SReclaimable:    2503268 kB
    SUnreclaim:       711012 kB
    KernelStack:       11312 kB
    PageTables:        11148 kB
    SecPageTables:      7988 kB
    NFS_Unstable:          0 kB
    Bounce:                0 kB
    WritebackTmp:          0 kB
    CommitLimit:    34198928 kB
    Committed_AS:    2906292 kB
    VmallocTotal:   34359738367 kB
    VmallocUsed:       83464 kB
    VmallocChunk:          0 kB
    Percpu:           150336 kB
    HardwareCorrupted:     0 kB
    AnonHugePages:     88064 kB
    ShmemHugePages:        0 kB
    ShmemPmdMapped:        0 kB
    FileHugePages:         0 kB
    FilePmdMapped:         0 kB
    Unaccepted:            0 kB
    HugePages_Total:       0
    HugePages_Free:        0
    HugePages_Rsvd:        0
    HugePages_Surp:        0
    Hugepagesize:       2048 kB
    Hugetlb:               0 kB
    DirectMap4k:      485000 kB
    DirectMap2M:    11773952 kB
    DirectMap1G:    54525952 kB
    ----------------------------------------
    [2025-09-02 17:03:04] exit code: 0 time: 5 ms
    ----------------------------------------


    * [proc_vmstat](file:///Users/stefank/environment.html#linux.memory.proc_vmstat)

    ----------------------------------------
    [2025-09-02 17:03:04] [/usr/bin/bash, -c, cat /proc/vmstat] timeout=20000 in /home/stefank/git/jdk/build/fastdebug/test-support/jtreg_open_test_hotspot_jtreg_gc_g1_TestPLABOutput_java/gc/g1/TestPLABOutput
    ----------------------------------------
    nr_free_pages 7208695
    nr_zone_inactive_anon 0
    nr_zone_active_anon 133612
    nr_zone_inactive_file 6763832
    nr_zone_active_file 967211
    nr_zone_unevictable 5479
    nr_zone_write_pending 57
    nr_mlock 5479
    nr_bounce 0
    nr_zspages 0
    nr_free_cma 0
    nr_unaccepted 0
    numa_hit 466716436
    numa_miss 0
    numa_foreign 0
    numa_interleave 2079
    numa_local 466714954
    numa_other 0
    nr_inactive_anon 0
    nr_active_anon 133612
    nr_inactive_file 6763832
    nr_active_file 967211
    nr_unevictable 5479
    nr_slab_reclaimable 625817
    nr_slab_unreclaimable 177753
    nr_isolated_anon 0
    nr_isolated_file 0
    workingset_nodes 0
    workingset_refault_anon 0
    workingset_refault_file 0
    workingset_activate_anon 0
    workingset_activate_file 0
    workingset_restore_anon 0
    workingset_restore_file 0
    workingset_nodereclaim 0
    nr_anon_pages 128545
    nr_mapped 98598
    nr_file_pages 7741593
    nr_dirty 57
    nr_writeback 0
    nr_writeback_temp 0
    nr_shmem 7734
    nr_shmem_hugepages 0
    nr_shmem_pmdmapped 0
    nr_file_hugepages 0
    nr_file_pmdmapped 0
    nr_anon_transparent_hugepages 43
    nr_vmscan_write 0
    nr_vmscan_immediate_reclaim 0
    nr_dirtied 25991300
    nr_written 22813677
    nr_throttled_written 0
    nr_kernel_misc_reclaimable 0
    nr_foll_pin_acquired 55140
    nr_foll_pin_released 55140
    nr_kernel_stack 11312
    nr_page_table_pages 2787
    nr_sec_page_table_pages 1997
    nr_iommu_pages 1997
    nr_swapcached 0
    pgpromote_success 0
    pgpromote_candidate 0
    pgdemote_kswapd 0
    pgdemote_direct 0
    pgdemote_khugepaged 0
    nr_dirty_threshold 2964299
    nr_dirty_background_threshold 1480339
    nr_memmap_pages 32768
    nr_memmap_boot_pages 261120
    pgpgin 10093202
    pgpgout 98915825
    pswpin 0
    pswpout 0
    pgalloc_dma 1024
    pgalloc_dma32 1034
    pgalloc_normal 478327697
    pgalloc_movable 0
    pgalloc_device 0
    allocstall_dma 0
    allocstall_dma32 0
    allocstall_normal 0
    allocstall_movable 0
    allocstall_device 0
    pgskip_dma 0
    pgskip_dma32 0
    pgskip_normal 0
    pgskip_movable 0
    pgskip_device 0
    pgfree 485576492
    pgactivate 0
    pgdeactivate 50
    pglazyfree 52187
    pgfault 490762863
    pgmajfault 24328
    pglazyfreed 0
    pgrefill 0
    pgreuse 27798266
    pgsteal_kswapd 0
    pgsteal_direct 0
    pgsteal_khugepaged 0
    pgscan_kswapd 0
    pgscan_direct 0
    pgscan_khugepaged 0
    pgscan_direct_throttle 0
    pgscan_anon 0
    pgscan_file 0
    pgsteal_anon 0
    pgsteal_file 0
    zone_reclaim_failed 0
    pginodesteal 0
    slabs_scanned 0
    kswapd_inodesteal 0
    kswapd_low_wmark_hit_quickly 0
    kswapd_high_wmark_hit_quickly 0
    pageoutrun 0
    pgrotated 23017
    drop_pagecache 0
    drop_slab 0
    oom_kill 0
    numa_pte_updates 0
    numa_huge_pte_updates 0
    numa_hint_faults 0
    numa_hint_faults_local 0
    numa_pages_migrated 0
    pgmigrate_success 0
    pgmigrate_fail 0
    thp_migration_success 0
    thp_migration_fail 0
    thp_migration_split 0
    compact_migrate_scanned 0
    compact_free_scanned 0
    compact_isolated 0
    compact_stall 0
    compact_fail 0
    compact_success 0
    compact_daemon_wake 0
    compact_daemon_migrate_scanned 0
    compact_daemon_free_scanned 0
    htlb_buddy_alloc_success 0
    htlb_buddy_alloc_fail 0
    unevictable_pgs_culled 34000
    unevictable_pgs_scanned 4050
    unevictable_pgs_rescued 5476
    unevictable_pgs_mlocked 6905
    unevictable_pgs_munlocked 1426
    unevictable_pgs_cleared 0
    unevictable_pgs_stranded 0
    thp_fault_alloc 12586
    thp_fault_fallback 0
    thp_fault_fallback_charge 0
    thp_collapse_alloc 241
    thp_collapse_alloc_failed 0
    thp_file_alloc 0
    thp_file_fallback 0
    thp_file_fallback_charge 0
    [thp](file:///Users/stefank/environment.html#linux.memory.thp)_file_mapped 0
    thp_split_page 0
    thp_split_page_failed 0
    thp_deferred_split_page 62
    thp_split_pmd 269
    thp_scan_exceed_none_pte 0
    thp_scan_exceed_swap_pte 0
    thp_scan_exceed_share_pte 9
    thp_split_pud 0
    thp_zero_page_alloc 1
    thp_zero_page_alloc_failed 0
    thp_swpout 0
    thp_swpout_fallback 0
    balloon_inflate 0
    balloon_deflate 0
    balloon_migrate 0
    swap_ra 0
    swap_ra_hit 0
    ksm_swpin_copy 0
    cow_ksm 0
    zswpin 0
    zswpout 0
    zswpwb 0
    direct_map_level2_splits 224
    direct_map_level3_splits 8
    nr_unstable 0
    ----------------------------------------
    [2025-09-02 17:03:04] exit code: 0 time: 4 ms
    ----------------------------------------


    * thp

    ----------------------------------------
    [2025-09-02 17:03:04] [/usr/bin/bash, -c, cat /sys/kernel/mm/transparent_hugepage/{enabled,defrag}] timeout=20000 in /home/stefank/git/jdk/build/fastdebug/test-support/jtreg_open_test_hotspot_jtreg_gc_g1_TestPLABOutput_java/gc/g1/TestPLABOutput
    ----------------------------------------
    always [madvise] never
    always defer defer+madvise madvise [never]
    ----------------------------------------
    [2025-09-02 17:03:04] exit code: 0 time: 5 ms

-------------

PR Comment: https://git.openjdk.org/jdk/pull/27086#issuecomment-3252227582


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