Messages in this thread | | | Date | Sat, 19 Mar 2022 01:54:09 +0000 | From | David Cohen <> | Subject | Re: [PATCH v2] PM: fix dynamic debug within pm_pr_debug() |
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On Thu, Mar 17, 2022 at 02:45:11PM +0100, Rafael J. Wysocki wrote: > On Sat, Mar 12, 2022 at 5:37 AM David Cohen <dacohen@pm.me> wrote: > > > > Currently, pm_pr_debug() and pm_deferred_pr_debug() use __pm_pr_debug() > > to filter pm debug messages based on pm_debug_messages_on flag. > > According to __pm_pr_debug() implementation, pm_deferred_pr_debug() > > indirectly calls printk_deferred() within __pm_pr_debug() which doesn't > > support dynamic debug, but pm_pr_debug() indirectly calls pr_debug() > > I'm not sure what you mean by pm_pr_debug(). There's no such thing in > the kernel tree. > > Assuming that it means pm_pr_dbg(), it doesn't call pr_debug():
Yeah, I apologize for the typo. I meant pm_pr_dbg(). I can fix that if you're ok with the patch as per comments below.
> > #define pm_pr_dbg(fmt, ...) __pm_pr_dbg(false, fmt, ##__VA_ARGS__) > > and > > void __pm_pr_dbg(bool defer, const char *fmt, ...) > { > ... > if (defer) > printk_deferred(KERN_DEBUG "PM: %pV", &vaf); > else > printk(KERN_DEBUG "PM: %pV", &vaf); > > And as I said printk(KERN_DEBUG ...) is not equivalent to > pr_debug(...), because it is not dynamic printk().
The problem is not about __pm_pr_dbg() calling printk(). The problem is the pm files that used to call pr_debug() were modified to call pm_pr_dbg() in order to be behing the pm_debug_messages_on flag, as per this commit: 8d8b2441db96 PM / sleep: Do not print debug messages by default
That's the moment dynamic debug was no longer available for kernel pm files.
> > pm_pr_dbg() is not dynamic printk() on purpose, so they both can be > controlled independently.
The current solution is all or nothing (using pm_debug_messages_on). The patch I'm sending is making dynamic debug available on the kernel pm files, while still allowing the pm_debug_messages_on flag to work independently.
Regards, David
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