Re: [PATCH 2/2] Add memory usage trace to diffrent hook points

[Vivek Goyal <vgoyal-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>]

On Mon, Nov 26, 2012 at 10:38:52AM +0800, Dave Young wrote:
> 
> 
> Port mkdumprd memory trace functions wrote by jstancek-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org
> For kdump, memory usage tracing is important because there's limited
> memory in kdump 2nd kernel.
> 
> Add a rd.memdebug cmdline for this. set rd.memdebug=<X> will set the
> debug level to X which is the debug verbose level.
> 
> I added several trace point to the begin of several init hooks
> At cmdline hooks I'm adding trace of "1+:mem 2+:iomem 3+:slab"
> For other hooks I'm adding trace of "1:shortmem 2+:mem 3+:slab"

Not everybody knows what is kdump functionality for debugging. Can you
please explain a bit more about the notion of 1+, 2+ etc.

> 
> This means:
> rd.memdebug=1)
>   cmdline hook: print /proc/meminfo

I think it is not a bad idea to print /proc/iomem for command line
hook in case of rd.memdebug=1. It is just one time print, so does
not hurt.

>   other hooks: print part of /proc/meminfo

We are calling it shortmem above. So  atleast put it in bracket so
that it is not confusing.

Thanks
Vivek

> rd.memdebug=2)
>   cmdline hook: show /proc/iomem and /proc/meminfo
>   other hooks: print /proc/meminfo
> rd.memdebug=3):
>   cmdline hook: print /proc/iomem, /proc/meminfo and /proc/slabinfo
>   other hooks: print /proc/meminfo and /proc/slabinfo
> *):
>   do not print any mem debug info
> 
> Signed-off-by: Dave Young <dyoung-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
> ---
>  dracut.cmdline.7.asc                      |    4 +
>  modules.d/98systemd/dracut-cmdline.sh     |    1 
>  modules.d/98systemd/dracut-initqueue.sh   |    1 
>  modules.d/98systemd/dracut-pre-pivot.sh   |    1 
>  modules.d/98systemd/dracut-pre-trigger.sh |    1 
>  modules.d/98systemd/dracut-pre-udev.sh    |    1 
>  modules.d/99base/dracut-lib.sh            |   90 ++++++++++++++++++++++++++++++
>  7 files changed, 99 insertions(+)
> 
> --- dracut.orig/modules.d/98systemd/dracut-cmdline.sh
> +++ dracut/modules.d/98systemd/dracut-cmdline.sh
> @@ -18,6 +18,7 @@ type getarg >/dev/null 2>&1 || . /lib/dr
>  
>  source_conf /etc/conf.d
>  
> +make_trace_mem "hook cmdline" 1+:mem 2+:iomem 3+:slab
>  # run scriptlets to parse the command line
>  getarg 'rd.break=cmdline' -d 'rdbreak=cmdline' && emergency_shell -n cmdline "Break before cmdline"
>  source_hook cmdline
> --- dracut.orig/modules.d/98systemd/dracut-initqueue.sh
> +++ dracut/modules.d/98systemd/dracut-initqueue.sh
> @@ -10,6 +10,7 @@ type getarg >/dev/null 2>&1 || . /lib/dr
>  
>  source_conf /etc/conf.d
>  
> +make_trace_mem "hook initqueue" 1:shortmem 2+:mem 3+:slab
>  getarg 'rd.break=initqueue' -d 'rdbreak=initqueue' && emergency_shell -n initqueue "Break before initqueue"
>  
>  RDRETRY=$(getarg rd.retry -d 'rd_retry=')
> --- dracut.orig/modules.d/98systemd/dracut-pre-pivot.sh
> +++ dracut/modules.d/98systemd/dracut-pre-pivot.sh
> @@ -10,6 +10,7 @@ type getarg >/dev/null 2>&1 || . /lib/dr
>  
>  source_conf /etc/conf.d
>  
> +make_trace_mem "hook pre-pivot" 1:shortmem 2+:mem 3+:slab
>  # pre pivot scripts are sourced just before we doing cleanup and switch over
>  # to the new root.
>  getarg 'rd.break=pre-pivot' 'rdbreak=pre-pivot' && emergency_shell -n pre-pivot "Break pre-pivot"
> --- dracut.orig/modules.d/98systemd/dracut-pre-trigger.sh
> +++ dracut/modules.d/98systemd/dracut-pre-trigger.sh
> @@ -10,6 +10,7 @@ type getarg >/dev/null 2>&1 || . /lib/dr
>  
>  source_conf /etc/conf.d
>  
> +make_trace_mem "hook pre-trigger" 1:shortmem 2+:mem 3+:slab
>  getargbool 0 rd.udev.info -n -y rdudevinfo && udevadm control --log-priority=info
>  getargbool 0 rd.udev.debug -n -y rdudevdebug && udevadm control --log-priority=debug
>  udevproperty "hookdir=$hookdir"
> --- dracut.orig/modules.d/98systemd/dracut-pre-udev.sh
> +++ dracut/modules.d/98systemd/dracut-pre-udev.sh
> @@ -9,6 +9,7 @@ type getarg >/dev/null 2>&1 || . /lib/dr
>  
>  source_conf /etc/conf.d
>  
> +make_trace_mem "hook pre-udev" 1:shortmem 2+:mem 3+:slab
>  # pre pivot scripts are sourced just before we doing cleanup and switch over
>  # to the new root.
>  getarg 'rd.break=pre-udev' 'rdbreak=pre-udev' && emergency_shell -n pre-udev "Break pre-udev"
> --- dracut.orig/dracut.cmdline.7.asc
> +++ dracut/dracut.cmdline.7.asc
> @@ -134,6 +134,10 @@ Debug
>      set -x for the dracut shell and logs to dmesg, console and
>      _/run/initramfs/init.log_
>  
> +**rd.memdebug=[0-3]**::
> +    print memory usage debug info, set the verbose level from 1 to 3
> +    print nothing when set rd.memdebug=0
> +
>  **rd.break**::
>      drop to a shell at the end
>  
> --- dracut.orig/modules.d/99base/dracut-lib.sh
> +++ dracut/modules.d/99base/dracut-lib.sh
> @@ -996,3 +996,93 @@ listlist() {
>  are_lists_eq() {
>      listlist "$1" "$2" "$3" "$4" && listlist "$1" "$3" "$2" "$4"
>  }
> +
> +setmemdebug() {
> +    if [ -z "$DEBUG_MEM_LEVEL" ]; then
> +        export DEBUG_MEM_LEVEL=$(getargnum 0 3 rd.memdebug)
> +    fi
> +}
> +
> +setmemdebug
> +
> +# parameters: msg [trace_level:trace]...
> +function make_trace_mem()
> +{
> +    msg=$1
> +    shift
> +    if [ "$DEBUG_MEM_LEVEL" -gt 0 ]; then
> +        make_trace show_memstats $DEBUG_MEM_LEVEL "[debug_mem]" "$msg" "$@"
> +    fi
> +}
> +
> +# parameters: func log_level prefix msg [trace_level:trace]...
> +function make_trace()
> +{
> +    func=$1
> +    shift
> +
> +    log_level=`echo "$1" | grep -o '^[0-9]\+'`
> +    shift
> +
> +    prefix=$1
> +    shift
> +
> +    msg=$1
> +    shift
> +
> +    if [ -z "$log_level" ]; then
> +        return
> +    fi
> +
> +    msg=`echo "$msg" | sed 's/^\s\+//'`
> +
> +    msg_printed=0
> +    while [ $# -gt 0 ]; do
> +        trace_level=`echo "$1" | grep -o '^[0-9]\+'`
> +        trace_in_higher_levels=`echo "$1" | grep -o '+'`
> +        trace=`echo $1 | sed "s/^.*://"`
> +
> +        if [ -z "$trace_level" ]; then
> +            trace_level=0
> +        fi
> +
> +        insert_trace=0
> +        if [ -n "$trace_in_higher_levels" ]; then
> +            if [ "$log_level" -ge "$trace_level" ]; then
> +                insert_trace=1
> +            fi
> +        else
> +            if [ "$log_level" -eq "$trace_level" ]; then
> +                insert_trace=1
> +            fi
> +        fi
> +
> +        if [ $insert_trace -eq 1 ]; then
> +            if [ $msg_printed -eq 0 ]; then
> +                echo "$prefix $msg"
> +                msg_printed=1
> +            fi
> +            $func $trace
> +        fi
> +        shift
> +    done
> +}
> +
> +# parameters: type
> +show_memstats()
> +{
> +    case $1 in
> +        shortmem)
> +            cat /proc/meminfo  | grep -e "^MemFree" -e "^Cached" -e "^Slab"
> +            ;;
> +        mem)
> +            cat /proc/meminfo
> +            ;;
> +        slab)
> +            cat /proc/slabinfo
> +            ;;
> +        iomem)
> +            cat /proc/iomem
> +            ;;
> +    esac
> +}
> --
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