lkml.org 
[lkml]   [2023]   [May]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH v5 08/18] watchdog/hardlockup: Move perf hardlockup checking/panic to common watchdog.c
    On Fri 2023-05-19 10:18:32, Douglas Anderson wrote:
    > The perf hardlockup detector works by looking at interrupt counts and
    > seeing if they change from run to run. The interrupt counts are
    > managed by the common watchdog code via its watchdog_timer_fn().
    >
    > Currently the API between the perf detector and the common code is a
    > function: is_hardlockup(). When the hard lockup detector sees that
    > function return true then it handles printing out debug info and
    > inducing a panic if necessary.
    >
    > Let's change the API a little bit in preparation for the buddy
    > hardlockup detector. The buddy hardlockup detector wants to print
    > nearly the same debug info and have nearly the same panic
    > behavior. That means we want to move all that code to the common
    > file. For now, the code in the common file will only be there if the
    > perf hardlockup detector is enabled, but eventually it will be
    > selected by a common config.
    >
    > Right now, this _just_ moves the code from the perf detector file to
    > the common file and changes the names. It doesn't make the changes
    > that the buddy hardlockup detector will need and doesn't do any style
    > cleanups. A future patch will do cleanup to make it more obvious what
    > changed.
    >
    > With the above, we no longer have any callers of is_hardlockup()
    > outside of the "watchdog.c" file, so we can remove it from the header,
    > make it static, and move it to the same "#ifdef" block as our new
    > watchdog_hardlockup_check(). While doing this, it can be noted that
    > even if no hardlockup detectors were configured the existing code used
    > to still have the code for counting/checking "hrtimer_interrupts" even
    > if the perf hardlockup detector wasn't configured. We didn't need to
    > do that, so move all the "hrtimer_interrupts" counting to only be
    > there if the perf hardlockup detector is configured as well.
    >
    > This change is expected to be a no-op.
    >
    > Signed-off-by: Douglas Anderson <dianders@chromium.org>

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

    Best Regards,
    Petr

    \
     
     \ /
      Last update: 2023-05-23 13:46    [W:2.414 / U:0.252 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site