lkml.org 
[lkml]   [2018]   [Dec]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH] printk: Add caller information to printk() output.
    On (12/04/18 19:16), Tetsuo Handa wrote:
    > On 2018/12/04 11:02, Sergey Senozhatsky wrote:
    > > On (12/02/18 20:23), Tetsuo Handa wrote:
    > >>
    > >> Some examples for console output:
    > >>
    > >> [ 0.919699]@T1 x86: Booting SMP configuration:
    > >> [ 4.152681]@T271 Fusion MPT base driver 3.04.20
    > >> [ 5.070470]@C0 random: fast init done
    > >> [ 6.587900]@C3 random: crng init done
    > >
    > > This is hard to read. Let's have a fixed width space for from_id.
    >
    > Console might be only 80 columns. When we have to check from screen capture of
    > crash, triggering needless newlines due to occupying columns more than needed
    > will not be nice. Also, syzbot has file size limit for saving console output.
    > Wasting with needless spaces increases possibility of loosing past lines.
    > Given that said, do you still want to waste precious columns with spaces?

    Well, if the feature will be useful for non-syzbot cases as well, as
    you mention below, then I'd say let's make the output human readable.
    To some extent, at least.

    I think we consume much more bytes on pr_fmt prefixes; and not all of them
    are very useful all the time.

    [..]
    [ 1.223872] nouveau 0000:01:00.0: DRM: DCB outp 00: 01000f02 00020030
    [ 1.224090] nouveau 0000:01:00.0: DRM: DCB outp 01: 02011f62 00020010
    [..]
    [ 2.676030] snd_hda_codec_realtek hdaudioC0D0: autoconfig for ALC662 rev3: line_outs=1 (0x14/0x0/0x0/0x0/0x0) type:line
    [ 2.676643] snd_hda_codec_realtek hdaudioC0D0: speaker_outs=0 (0x0/0x0/0x0/0x0/0x0)
    [ 2.677258] snd_hda_codec_realtek hdaudioC0D0: hp_outs=1 (0x1b/0x0/0x0/0x0/0x0)
    [ 2.677879] snd_hda_codec_realtek hdaudioC0D0: mono: mono_out=0x0
    [ 2.678578] snd_hda_codec_realtek hdaudioC0D0: inputs:
    [ 2.679150] snd_hda_codec_realtek hdaudioC0D0: Front Mic=0x19
    [..]
    [ 430.768498] rndis_host 1-1:1.0 enp0s20f0u1: unregister 'rndis_host' usb-0000:00:14.0-1, RNDIS device


    So, to me, PRINTK_FROM probably does not look like a really bad
    serial console abuser. How many bytes do we need for PRINTK_FROM?
    7-8?

    > CONFIG_DEBUG_AID_FOR_SYZBOT is currently linux-next only option.
    > This feature will be useful for non-syzbot environments.

    -ss

    \
     
     \ /
      Last update: 2018-12-04 11:39    [W:4.751 / U:0.008 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site