lkml.org 
[lkml]   [2023]   [Mar]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    From
    Date
    SubjectRe: [PATCH 10/13] PM / QoS: Teach lockdep about dev_pm_qos_mtx locking order
    On Sun, Mar 12, 2023 at 9:42 PM Rob Clark <robdclark@gmail.com> wrote:
    >
    > From: Rob Clark <robdclark@chromium.org>
    >
    > Annotate dev_pm_qos_mtx to teach lockdep to scream about allocations
    > that could trigger reclaim under dev_pm_qos_mtx.

    So why is this needed?

    > Signed-off-by: Rob Clark <robdclark@chromium.org>
    > ---
    > drivers/base/power/qos.c | 11 +++++++++++
    > 1 file changed, 11 insertions(+)
    >
    > diff --git a/drivers/base/power/qos.c b/drivers/base/power/qos.c
    > index 9cba334b3729..d4addda3944a 100644
    > --- a/drivers/base/power/qos.c
    > +++ b/drivers/base/power/qos.c
    > @@ -1012,3 +1012,14 @@ void dev_pm_qos_hide_latency_tolerance(struct device *dev)
    > pm_runtime_put(dev);
    > }
    > EXPORT_SYMBOL_GPL(dev_pm_qos_hide_latency_tolerance);
    > +
    > +static int __init dev_pm_qos_init(void)
    > +{
    > + /* Teach lockdep about lock ordering wrt. shrinker: */
    > + fs_reclaim_acquire(GFP_KERNEL);
    > + might_lock(&dev_pm_qos_mtx);
    > + fs_reclaim_release(GFP_KERNEL);
    > +
    > + return 0;
    > +}
    > +early_initcall(dev_pm_qos_init);
    > --
    > 2.39.2
    >

    \
     
     \ /
      Last update: 2023-03-27 00:56    [W:2.958 / U:0.036 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site