Fast memory rollup

One-shot Rss/Pss/Swap totals without parsing full smaps; cheap on huge maps

cat /proc/<pid>/smaps_rollup
tool
troubleshooting32 commands
tags
troubleshootingmemorydebugperformance

More troubleshooting commands

  • Largest memory mappings
    pmap -x <pid> | sort -k3 -rn | head

    Top RSS mappings by region; spot a leaking heap, mmap or shared lib bloat

  • Kernel slab top consumers
    slabtop -o -s c | head -20

    Sort slab caches by size; dentry/inode bloat explains kernel memory pressure

  • Reclaimable slab memory
    grep -E 'Slab|SReclaimable|SUnreclaim' /proc/meminfo

    Split slab into reclaimable vs unreclaimable; high SUnreclaim = real kernel leak

  • OOM killer in dmesg
    dmesg -T | grep -iE 'killed process|out of memory' | tail

    Find OOM victims with human timestamps; -T avoids unreadable kernel ticks

  • OOM score of process
    cat /proc/<pid>/oom_score /proc/<pid>/oom_score_adj

    Higher oom_score = likelier victim; set oom_score_adj -1000 to immunize a pid

all 32 troubleshooting commands