Date: Sun, 5 Dec 2010 19:44:29 +0100 From: Thomas Zander <thomas.e.zander@googlemail.com> To: freebsd-stable <freebsd-stable@freebsd.org> Subject: Re: DTrace (or other monitor) access to LBA of a block device Message-ID: <AANLkTintS%2B-%2B3XJb3K7z6n%2B6Ngx=oJ90VV_bPGLVAOm_@mail.gmail.com> In-Reply-To: <AANLkTim2VCanQ1Sp15GU5Td8bL=J-8drkoZPKqTgbwtv@mail.gmail.com> References: <AANLkTi=2Ln5s-mD%2B%2B-iKEq2v-1f31fpavXB7kUfTC2Lf@mail.gmail.com> <AANLkTikWoCmRQE6VDG1S88s5UCtXY7acP1Q_pwo=gYY%2B@mail.gmail.com> <AANLkTim2VCanQ1Sp15GU5Td8bL=J-8drkoZPKqTgbwtv@mail.gmail.com>
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On Sun, Dec 5, 2010 at 19:02, Artem Belevich <fbsdlist@src.cx> wrote:
>> GEOM sounds like a good candidate for probing of that kind.
>>
>> sudo dtrace -n 'fbt:kernel:g_io_deliver:entry { printf("%s %d %d
>> %d\n",stringof(args[0]->bio_from->geom->name), args[0]->bio_cmd,
>> args[0]->bio_offset, args[0]->bio_length); }'
>
> By the way, in order for this to work one would need r207057 applied
> to -8. Any chance that could be MFC'ed?
In the meantime, a workaround is an explicit cast. Using
((struct bio *)arg0)
instead of
args[0]
works.
Or wrapped in a tiny d script:
#!/usr/sbin/dtrace -s
#pragma D option quiet
fbt:kernel:g_io_deliver:entry
{
bio = (struct bio *)arg0;
printf("%s %d %d %d\n",stringof(bio->bio_from->geom->name),
bio->bio_cmd, bio->bio_offset, bio->bio_length);
}
Riggs
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