Eric Lee / smarc-fsl-linux-kernel

03 May, 2017

1 commit

16 Dec, 2016

1 commit

  • d40fc181e   samples/bpf: Make samples more libbpf-centric ... Browse Code »

    Switch all of the sample code to use the function names from
    tools/lib/bpf so that they're consistent with that, and to declare their
    own log buffers. This allow the next commit to be purely devoted to
    getting rid of the duplicate library in samples/bpf.

    Committer notes:

    Testing it:

    On a fedora rawhide container, with clang/llvm 3.9, sharing the host
    linux kernel git tree:

    # make O=/tmp/build/linux/ headers_install
    # make O=/tmp/build/linux -C samples/bpf/

    Since I forgot to make it privileged, just tested it outside the
    container, using what it generated:

    # uname -a
    Linux jouet 4.9.0-rc8+ #1 SMP Mon Dec 12 11:20:49 BRT 2016 x86_64 x86_64 x86_64 GNU/Linux
    # cd /var/lib/docker/devicemapper/mnt/c43e09a53ff56c86a07baf79847f00e2cc2a17a1e2220e1adbf8cbc62734feda/rootfs/tmp/build/linux/samples/bpf/
    # ls -la offwaketime
    -rwxr-xr-x. 1 root root 24200 Dec 15 12:19 offwaketime
    # file offwaketime
    offwaketime: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, for GNU/Linux 2.6.32, BuildID[sha1]=c940d3f127d5e66cdd680e42d885cb0b64f8a0e4, not stripped
    # readelf -SW offwaketime_kern.o | grep PROGBITS
    [ 2] .text PROGBITS 0000000000000000 000040 000000 00 AX 0 0 4
    [ 3] kprobe/try_to_wake_up PROGBITS 0000000000000000 000040 0000d8 00 AX 0 0 8
    [ 5] tracepoint/sched/sched_switch PROGBITS 0000000000000000 000118 000318 00 AX 0 0 8
    [ 7] maps PROGBITS 0000000000000000 000430 000050 00 WA 0 0 4
    [ 8] license PROGBITS 0000000000000000 000480 000004 00 WA 0 0 1
    [ 9] version PROGBITS 0000000000000000 000484 000004 00 WA 0 0 4
    # ./offwaketime | head -5
    swapper/1;start_secondary;cpu_startup_entry;schedule_preempt_disabled;schedule;__schedule;-;---;; 106
    CPU 0/KVM;entry_SYSCALL_64_fastpath;sys_ioctl;do_vfs_ioctl;kvm_vcpu_ioctl;kvm_arch_vcpu_ioctl_run;kvm_vcpu_block;schedule;__schedule;-;try_to_wake_up;swake_up_locked;swake_up;apic_timer_expired;apic_timer_fn;__hrtimer_run_queues;hrtimer_interrupt;local_apic_timer_interrupt;smp_apic_timer_interrupt;__irqentry_text_start;cpuidle_enter;call_cpuidle;cpu_startup_entry;start_secondary;;swapper/3 2
    Compositor;entry_SYSCALL_64_fastpath;sys_futex;do_futex;futex_wait;futex_wait_queue_me;schedule;__schedule;-;try_to_wake_up;futex_requeue;do_futex;sys_futex;entry_SYSCALL_64_fastpath;;SoftwareVsyncTh 5
    firefox;entry_SYSCALL_64_fastpath;sys_poll;do_sys_poll;poll_schedule_timeout;schedule_hrtimeout_range;schedule_hrtimeout_range_clock;schedule;__schedule;-;try_to_wake_up;pollwake;__wake_up_common;__wake_up_sync_key;pipe_write;__vfs_write;vfs_write;sys_write;entry_SYSCALL_64_fastpath;;Timer 13
    JS Helper;entry_SYSCALL_64_fastpath;sys_futex;do_futex;futex_wait;futex_wait_queue_me;schedule;__schedule;-;try_to_wake_up;do_futex;sys_futex;entry_SYSCALL_64_fastpath;;firefox 2
    #

    Signed-off-by: Joe Stringer
    Tested-by: Arnaldo Carvalho de Melo
    Cc: Alexei Starovoitov
    Cc: Daniel Borkmann
    Cc: Wang Nan
    Cc: netdev@vger.kernel.org
    Link: http://lkml.kernel.org/r/20161214224342.12858-2-joe@ovn.org
    Signed-off-by: Arnaldo Carvalho de Melo

    Joe Stringer
     

02 Apr, 2015

1 commit

  • 9811e3535   samples/bpf: Add kmem_alloc()/free() tracker tool ... Browse Code »

    One BPF program attaches to kmem_cache_alloc_node() and
    remembers all allocated objects in the map.
    Another program attaches to kmem_cache_free() and deletes
    corresponding object from the map.

    User space walks the map every second and prints any objects
    which are older than 1 second.

    Usage:

    $ sudo tracex4

    Then start few long living processes. The 'tracex4' will print
    something like this:

    obj 0xffff880465928000 is 13sec old was allocated at ip ffffffff8105dc32
    obj 0xffff88043181c280 is 13sec old was allocated at ip ffffffff8105dc32
    obj 0xffff880465848000 is 8sec old was allocated at ip ffffffff8105dc32
    obj 0xffff8804338bc280 is 15sec old was allocated at ip ffffffff8105dc32

    $ addr2line -fispe vmlinux ffffffff8105dc32
    do_fork at fork.c:1665

    As soon as processes exit the memory is reclaimed and 'tracex4'
    prints nothing.

    Similar experiment can be done with the __kmalloc()/kfree() pair.

    Signed-off-by: Alexei Starovoitov
    Cc: Andrew Morton
    Cc: Arnaldo Carvalho de Melo
    Cc: Arnaldo Carvalho de Melo
    Cc: Daniel Borkmann
    Cc: David S. Miller
    Cc: Jiri Olsa
    Cc: Linus Torvalds
    Cc: Masami Hiramatsu
    Cc: Namhyung Kim
    Cc: Peter Zijlstra
    Cc: Peter Zijlstra
    Cc: Steven Rostedt
    Link: http://lkml.kernel.org/r/1427312966-8434-10-git-send-email-ast@plumgrid.com
    Signed-off-by: Ingo Molnar

    Alexei Starovoitov