Skip site navigation (1)Skip section navigation (2)
Date:      Fri, 7 Apr 2023 12:36:15 -0700
From:      Alan Somers <asomers@freebsd.org>
To:        Warner Losh <imp@bsdimp.com>
Cc:        Poul-Henning Kamp <phk@phk.freebsd.dk>, FreeBSD CURRENT <freebsd-current@freebsd.org>
Subject:   Re: textdumps are too slow
Message-ID:  <CAOtMX2gbpy4AXXScbEsc5ho3cv7M%2BT8aVuwyak-PeSdzPqOd_g@mail.gmail.com>
In-Reply-To: <CANCZdfroaGxPLT_PkhqXqJ07JovCv-TChf5AecxquPG6SKo=eA@mail.gmail.com>
References:  <CAOtMX2j-Muz2uFE5YkYQ7atvQO9VrT4pDdvVnay-S%2BNi6rZNMQ@mail.gmail.com> <202304070922.3379MVW5077791@critter.freebsd.dk> <CAOtMX2go2PKC-hDOncJjHxfZRSY3AMGRSGXDF20O%2BzjFoQs=uA@mail.gmail.com> <202304071220.337CK7XH083443@critter.freebsd.dk> <CANCZdfroaGxPLT_PkhqXqJ07JovCv-TChf5AecxquPG6SKo=eA@mail.gmail.com>

next in thread | previous in thread | raw e-mail | index | archive | help
On Fri, Apr 7, 2023 at 12:08=E2=80=AFPM Warner Losh <imp@bsdimp.com> wrote:
>
>
>
> On Fri, Apr 7, 2023 at 6:20=E2=80=AFAM Poul-Henning Kamp <phk@phk.freebsd=
.dk> wrote:
>>
>> --------
>> Alan Somers writes:
>> > On Fri, Apr 7, 2023 at 2:22=3DE2=3D80=3DAFAM Poul-Henning Kamp <phk@ph=
k.freebsd.dk> wrote:
>>
>> > > I would expect them to be limited by the serial console speed before
>> > > the video system speed ?
>> >
>> > That was my first guess, too.  But my serial console is 115200 baud,
>> > which is faster than the low performance server grade video card.
>>
>> Ok, that must truly be sucky hardware...
>
>
> That's 10x slower than 1990s era VGA cards then... 115200 is 11k characte=
rs a second,
> and FreeBSD on 1990s era VGA cards was in excess of 1MB/s, faster if not =
a pure ISA
> card... Video hardware that's slower than *THAT* likely indicates a big b=
ig problem in
> our video stack.
>
> Warner

While I'm logged into the video terminal in a normal login session, I
measure about 28M characters/second.  So maybe the slow speed is due
to something inefficient in ddb(4).



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?CAOtMX2gbpy4AXXScbEsc5ho3cv7M%2BT8aVuwyak-PeSdzPqOd_g>