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From: Xunlei Pang <xpang-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
To: Dave Young <dyoung-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>,
	xlpang-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org
Cc: Harald Hoyer <harald-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>,
	initramfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	Pratyush Anand <panand-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
Subject: Re: [RFC PATCH 1/2] add 99memdebug-ko dracut module
Date: Fri, 4 Nov 2016 17:12:34 +0800	[thread overview]
Message-ID: <581C5102.60700@redhat.com> (raw)
In-Reply-To: <20161104082328.GA19275-0VdLhd/A9Pl+NNSt+8eSiB/sF2h8X+2i0E9HWUfgJXw@public.gmane.org>

On 2016/11/04 at 16:23, Dave Young wrote:
> Hi Xunlei,
>
>>> If change the logic a bit, it will be clear:
>>>
>>> is_trace_prepared()
>>> {
>>>     this function only check if tracing is enabled and events matched.
>>> }
>>>
>>> prepare_trace()
>>> {
>>>     enable and prepare trace
>>> }
>>>
>>> parse_trace_data()
>>> {
>>>
>>> }
>>>
>>> if is_trace_prepared == true; then
>>>     parse_trace_data
>>> else
>>>     prepare_trace
>>> fi
>>>
>>> So in cmdline hook is_trace_prepared is false so the script only prepare
>>> trace and enable tracing, in latter hooks it will parse trace data.
>>>
>>> But there should be another function to disable trace before pivot root.
>> OK
>>
>> We should find a neat way to disable the trace function, what do you think the following way?
>> Change show_memstats() and make_trace_mem() as follows:
>>     make_trace_mem "hook cmdline" '1+:mem' '1+:iomem' '3+:slab' '4+:komem'
>>     ... ...
>>     make_trace_mem "hook pre-pivot" '1+:mem' '1+:iomem' '3+:slab' '4+:komem'
>>     make_trace_mem "hook pre-pivot" '4+:komemfinish' # cleanup trace used by showkomem after use.
>>
>>    show_memstats()
>>            ... ...
>>
>> +        komem)
>> +            showkomem
>> +            ;;
>> +        komemfinish)
>> +            # disable trace after use.
>> +            showkomem finish
>> +            ;;
>>      esac
>>
> Hmm, I'm not sure it is worth, maybe add a function like
> cleanup_trace_mem() is enough and we can add it just before cleanup
> hook which is designed for cleanup purpose, cleanup hook is sourced
> after pre-pivot so that it will still work for adding trace in any
> pre-pivot scripts.

OK

I'll send v2 later, thanks for all the valuable suggestions.

Regards,
Xunlei

      parent reply	other threads:[~2016-11-04  9:12 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-11-02  9:03 [RFC PATCH 1/2] add 99memdebug-ko dracut module Xunlei Pang
     [not found] ` <1478077386-30039-1-git-send-email-xlpang-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2016-11-02  9:03   ` [RFC PATCH 2/2] dracut.cmdline.7.asc: update document for rd.memdebug=4 Xunlei Pang
2016-11-03  3:01   ` [RFC PATCH 1/2] add 99memdebug-ko dracut module Dave Young
     [not found]     ` <20161103030142.GA3201-0VdLhd/A9Pl+NNSt+8eSiB/sF2h8X+2i0E9HWUfgJXw@public.gmane.org>
2016-11-03  4:15       ` Xunlei Pang
     [not found]         ` <581AB9D7.2010905-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2016-11-03  4:45           ` Xunlei Pang
2016-11-03  7:28           ` Xunlei Pang
     [not found]             ` <581AE707.9050606-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2016-11-03  8:38               ` Dave Young
     [not found]                 ` <20161103083826.GA15431-0VdLhd/A9Pl+NNSt+8eSiB/sF2h8X+2i0E9HWUfgJXw@public.gmane.org>
2016-11-03 11:52                   ` Xunlei Pang
     [not found]                     ` <581B2518.6060503-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2016-11-04  5:50                       ` Dave Young
     [not found]                         ` <20161104055026.GB2889-0VdLhd/A9Pl+NNSt+8eSiB/sF2h8X+2i0E9HWUfgJXw@public.gmane.org>
2016-11-04  6:35                           ` Xunlei Pang
     [not found]                             ` <581C2C30.8070403-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2016-11-04  7:06                               ` Dave Young
     [not found]                                 ` <20161104070629.GA17145-0VdLhd/A9Pl+NNSt+8eSiB/sF2h8X+2i0E9HWUfgJXw@public.gmane.org>
2016-11-04  7:55                                   ` Xunlei Pang
     [not found]                                     ` <581C3EDE.9080601-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2016-11-04  8:23                                       ` Dave Young
     [not found]                                         ` <20161104082328.GA19275-0VdLhd/A9Pl+NNSt+8eSiB/sF2h8X+2i0E9HWUfgJXw@public.gmane.org>
2016-11-04  9:12                                           ` Xunlei Pang [this message]

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