lkml.org 
[lkml]   [2022]   [Feb]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH V6] panic: Move panic_print before kmsg dumpers
    On Mon 2022-02-14 11:13:09, Guilherme G. Piccoli wrote:
    > The panic_print setting allows users to collect more information in a
    > panic event, like memory stats, tasks, CPUs backtraces, etc.
    > This is an interesting debug mechanism, but currently the print event
    > happens *after* kmsg_dump(), meaning that pstore, for example, cannot
    > collect a dmesg with the panic_print extra information.
    >
    > This patch changes that in 2 steps:
    >
    > (a) The panic_print setting allows to replay the existing kernel log
    > buffer to the console (bit 5), besides the extra information dump.
    > This functionality makes sense only at the end of the panic() function.
    > So, we hereby allow to distinguish the two situations by a new boolean
    > parameter in the function panic_print_sys_info().
    >
    > (b) With the above change, we can safely call panic_print_sys_info()
    > before kmsg_dump(), allowing to dump the extra information when using
    > pstore or other kmsg dumpers.
    >
    > The additional messages from panic_print could overwrite the oldest
    > messages when the buffer is full. The only reasonable solution is to
    > use a large enough log buffer, hence we added an advice into the kernel
    > parameters documentation about that.
    >
    > Cc: Feng Tang <feng.tang@intel.com>
    > Cc: Petr Mladek <pmladek@suse.com>
    > Acked-by: Baoquan He <bhe@redhat.com>
    > Signed-off-by: Guilherme G. Piccoli <gpiccoli@igalia.com>

    Makes sense and looks good to me.

    Reviewed-by: Petr Mladek <pmladek@suse.com>

    Best Regards,
    Petr

    \
     
     \ /
      Last update: 2022-02-15 17:28    [W:8.922 / U:0.276 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site