Commit 09e1d93a authored by Illia Ostapyshyn's avatar Illia Ostapyshyn Committed by Andrew Morton
Browse files

scripts/gdb: update documentation for lx_per_cpu 

Commit db08c53f ("scripts/gdb: fix parameter handling in
$lx_per_cpu") changed the parameter handling of lx_per_cpu to use GdbValue
instead of parsing the variable name.  Update the documentation to reflect
the new lx_per_cpu usage.  Update the hrtimer_bases example to use rb_tree
instead of the timerqueue_head.next pointer removed in commit
511885d7 ("lib/timerqueue: Rely on rbtree semantics for next
timer").

Link: https://lkml.kernel.org/r/20250503123234.2407184-3-illia@yshyn.com


Signed-off-by: default avatarIllia Ostapyshyn <illia@yshyn.com>
Cc: Alex Shi <alexs@kernel.org>
Cc: Brendan Jackman <jackmanb@google.com>
Cc: Dongliang Mu <dzm91@hust.edu.cn>
Cc: Florian Rommel <mail@florommel.de>
Cc: Hu Haowen <2023002089@link.tyut.edu.cn>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kieran Bingham <kbingham@kernel.org>
Cc: Yanteng Si <si.yanteng@linux.dev>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 6be7045c

Documentation/process/debugging/gdb-kernel-debugging.rst

+15 −19
Original line number Diff line number Diff line
@@ -127,35 +127,31 @@ Examples of using the Linux-provided gdb helpers 


- Make use of the per-cpu function for the current or a specified CPU::



    (gdb) p $lx_per_cpu("runqueues").nr_running

    (gdb) p $lx_per_cpu(runqueues).nr_running

    $3 = 1

    (gdb) p $lx_per_cpu("runqueues", 2).nr_running

    (gdb) p $lx_per_cpu(runqueues, 2).nr_running

    $4 = 0



- Dig into hrtimers using the container_of helper::



    (gdb) set $next = $lx_per_cpu("hrtimer_bases").clock_base[0].active.next

    (gdb) p *$container_of($next, "struct hrtimer", "node")

    (gdb) set $leftmost = $lx_per_cpu(hrtimer_bases).clock_base[0].active.rb_root.rb_leftmost

    (gdb) p *$container_of($leftmost, "struct hrtimer", "node")

    $5 = {

      node = {

        node = {

          __rb_parent_color = 18446612133355256072,

          rb_right = 0x0 <irq_stack_union>,

          rb_left = 0x0 <irq_stack_union>

          __rb_parent_color = 18446612686384860673,

          rb_right = 0xffff888231da8b00,

          rb_left = 0x0

        },

        expires = {

          tv64 = 1835268000000

        }

      },

      _softexpires = {

        tv64 = 1835268000000

        expires = 1228461000000

      },

      function = 0xffffffff81078232 <tick_sched_timer>,

      base = 0xffff88003fd0d6f0,

      state = 1,

      start_pid = 0,

      start_site = 0xffffffff81055c1f <hrtimer_start_range_ns+20>,

      start_comm = "swapper/2\000\000\000\000\000\000"

      _softexpires = 1228461000000,

      function = 0xffffffff8137ab20 <tick_nohz_handler>,

      base = 0xffff888231d9b4c0,

      state = 1 '\001',

      is_rel = 0 '\000',

      is_soft = 0 '\000',

      is_hard = 1 '\001'

    }

Documentation/translations/zh_CN/dev-tools/gdb-kernel-debugging.rst

+15 −19
Original line number Diff line number Diff line
@@ -120,35 +120,31 @@ Kgdb内核调试器、QEMU等虚拟机管理程序或基于JTAG的硬件接口 


- 对当前或指定的CPU使用per-cpu函数::



    (gdb) p $lx_per_cpu("runqueues").nr_running

    (gdb) p $lx_per_cpu(runqueues).nr_running

    $3 = 1

    (gdb) p $lx_per_cpu("runqueues", 2).nr_running

    (gdb) p $lx_per_cpu(runqueues, 2).nr_running

    $4 = 0



- 使用container_of查看更多hrtimers信息::



    (gdb) set $next = $lx_per_cpu("hrtimer_bases").clock_base[0].active.next

    (gdb) p *$container_of($next, "struct hrtimer", "node")

    (gdb) set $leftmost = $lx_per_cpu(hrtimer_bases).clock_base[0].active.rb_root.rb_leftmost

    (gdb) p *$container_of($leftmost, "struct hrtimer", "node")

    $5 = {

      node = {

        node = {

          __rb_parent_color = 18446612133355256072,

          rb_right = 0x0 <irq_stack_union>,

          rb_left = 0x0 <irq_stack_union>

          __rb_parent_color = 18446612686384860673,

          rb_right = 0xffff888231da8b00,

          rb_left = 0x0

        },

        expires = {

          tv64 = 1835268000000

        }

      },

      _softexpires = {

        tv64 = 1835268000000

        expires = 1228461000000

      },

      function = 0xffffffff81078232 <tick_sched_timer>,

      base = 0xffff88003fd0d6f0,

      state = 1,

      start_pid = 0,

      start_site = 0xffffffff81055c1f <hrtimer_start_range_ns+20>,

      start_comm = "swapper/2\000\000\000\000\000\000"

      _softexpires = 1228461000000,

      function = 0xffffffff8137ab20 <tick_nohz_handler>,

      base = 0xffff888231d9b4c0,

      state = 1 '\001',

      is_rel = 0 '\000',

      is_soft = 0 '\000',

      is_hard = 1 '\001'

    }

Documentation/translations/zh_TW/dev-tools/gdb-kernel-debugging.rst

+15 −19
Original line number Diff line number Diff line
@@ -116,35 +116,31 @@ Kgdb內核調試器、QEMU等虛擬機管理程序或基於JTAG的硬件接口 


- 對當前或指定的CPU使用per-cpu函數::



    (gdb) p $lx_per_cpu("runqueues").nr_running

    (gdb) p $lx_per_cpu(runqueues).nr_running

    $3 = 1

    (gdb) p $lx_per_cpu("runqueues", 2).nr_running

    (gdb) p $lx_per_cpu(runqueues, 2).nr_running

    $4 = 0



- 使用container_of查看更多hrtimers信息::



    (gdb) set $next = $lx_per_cpu("hrtimer_bases").clock_base[0].active.next

    (gdb) p *$container_of($next, "struct hrtimer", "node")

    (gdb) set $leftmost = $lx_per_cpu(hrtimer_bases).clock_base[0].active.rb_root.rb_leftmost

    (gdb) p *$container_of($leftmost, "struct hrtimer", "node")

    $5 = {

      node = {

        node = {

          __rb_parent_color = 18446612133355256072,

          rb_right = 0x0 <irq_stack_union>,

          rb_left = 0x0 <irq_stack_union>

          __rb_parent_color = 18446612686384860673,

          rb_right = 0xffff888231da8b00,

          rb_left = 0x0

        },

        expires = {

          tv64 = 1835268000000

        }

      },

      _softexpires = {

        tv64 = 1835268000000

        expires = 1228461000000

      },

      function = 0xffffffff81078232 <tick_sched_timer>,

      base = 0xffff88003fd0d6f0,

      state = 1,

      start_pid = 0,

      start_site = 0xffffffff81055c1f <hrtimer_start_range_ns+20>,

      start_comm = "swapper/2\000\000\000\000\000\000"

      _softexpires = 1228461000000,

      function = 0xffffffff8137ab20 <tick_nohz_handler>,

      base = 0xffff888231d9b4c0,

      state = 1 '\001',

      is_rel = 0 '\000',

      is_soft = 0 '\000',

      is_hard = 1 '\001'

    }

scripts/gdb/linux/cpus.py

+2 −2
Original line number Diff line number Diff line
@@ -141,7 +141,7 @@ LxCpus() 
class PerCpu(gdb.Function):

    """Return per-cpu variable.



$lx_per_cpu("VAR"[, CPU]): Return the per-cpu variable called VAR for the

$lx_per_cpu(VAR[, CPU]): Return the per-cpu variable called VAR for the

given CPU number. If CPU is omitted, the CPU of the current context is used.

Note that VAR has to be quoted as string."""
@@ -158,7 +158,7 @@ PerCpu() 
class PerCpuPtr(gdb.Function):

    """Return per-cpu pointer.



$lx_per_cpu_ptr("VAR"[, CPU]): Return the per-cpu pointer called VAR for the

$lx_per_cpu_ptr(VAR[, CPU]): Return the per-cpu pointer called VAR for the

given CPU number. If CPU is omitted, the CPU of the current context is used.

Note that VAR has to be quoted as string."""