[patch] complain when users abuse the pm_qos API
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From: mark gross on 29 May 2010 01:00 The following patch is to help clean up API abusers of pm_qos where they call update_request before registering a request. --mgross --Signed-off-by: markgross <markgross(a)thegnar.org> From a0813007ddc7b72cb3da7a533fefba9889aab1d8 Mon Sep 17 00:00:00 2001 From: mgross <mgross(a)mgross-desktop.(none)> Date: Fri, 28 May 2010 21:36:06 -0700 Subject: [PATCH] complain when users abuse the pm_qos API by updating a request that isn't registered yet. --- kernel/pm_qos_params.c | 4 ++++ 1 files changed, 4 insertions(+), 0 deletions(-) diff --git a/kernel/pm_qos_params.c b/kernel/pm_qos_params.c index f42d3f7..8e55bf1 100644 --- a/kernel/pm_qos_params.c +++ b/kernel/pm_qos_params.c @@ -266,6 +266,10 @@ void pm_qos_update_request(struct pm_qos_request_list *pm_qos_req, spin_unlock_irqrestore(&pm_qos_lock, flags); if (pending_update) update_target(pm_qos_req->pm_qos_class); + } else { + WARN(true, "pm_qos: updating an unregistered request " + "does nothing"); + dump_stack(); } } EXPORT_SYMBOL_GPL(pm_qos_update_request); -- 1.7.0.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Nigel Cunningham on 29 May 2010 19:10 Hi. On 30/05/10 06:08, Rafael J. Wysocki wrote: > On Saturday 29 May 2010, mark gross wrote: >> The following patch is to help clean up API abusers of pm_qos where >> they call update_request before registering a request. >> >> --mgross >> >> --Signed-off-by: markgross<markgross(a)thegnar.org> > > Will there be a big issue if I push this during the next merge window? What's the point to the patch? That is: why is calling update_request before registering a request such a big problem that it demands a WARN() and dump stack? Regards, Nigel -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Rafael J. Wysocki on 30 May 2010 15:50 On Sunday 30 May 2010, Nigel Cunningham wrote: > Hi. > > On 30/05/10 06:08, Rafael J. Wysocki wrote: > > On Saturday 29 May 2010, mark gross wrote: > >> The following patch is to help clean up API abusers of pm_qos where > >> they call update_request before registering a request. > >> > >> --mgross > >> > >> --Signed-off-by: markgross<markgross(a)thegnar.org> > > > > Will there be a big issue if I push this during the next merge window? > > What's the point to the patch? That is: why is calling update_request > before registering a request such a big problem that it demands a WARN() > and dump stack? It is an API violation if I understand that correctly. Rafael -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: mark gross on 30 May 2010 16:10 On Sun, May 30, 2010 at 09:03:18AM +1000, Nigel Cunningham wrote: > Hi. > > On 30/05/10 06:08, Rafael J. Wysocki wrote: > >On Saturday 29 May 2010, mark gross wrote: > >>The following patch is to help clean up API abusers of pm_qos where > >>they call update_request before registering a request. > >> > >>--mgross > >> > >>--Signed-off-by: markgross<markgross(a)thegnar.org> > > > >Will there be a big issue if I push this during the next merge window? > > What's the point to the patch? That is: why is calling > update_request before registering a request such a big problem that > it demands a WARN() and dump stack? If e1000e realy needs the latency set and makes assumptions that its done its part, I would like to let them know that they have not registerd the request they thought they did. --mgross > > Regards, > > Nigel -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: mark gross on 30 May 2010 16:20
On Sun, May 30, 2010 at 09:50:01PM +0200, Rafael J. Wysocki wrote: > On Sunday 30 May 2010, Nigel Cunningham wrote: > > Hi. > > > > On 30/05/10 06:08, Rafael J. Wysocki wrote: > > > On Saturday 29 May 2010, mark gross wrote: > > >> The following patch is to help clean up API abusers of pm_qos where > > >> they call update_request before registering a request. > > >> > > >> --mgross > > >> > > >> --Signed-off-by: markgross<markgross(a)thegnar.org> > > > > > > Will there be a big issue if I push this during the next merge window? > > > > What's the point to the patch? That is: why is calling update_request > > before registering a request such a big problem that it demands a WARN() > > and dump stack? > > It is an API violation if I understand that correctly. Yeah, it is, but now that I'm thinking clearly perhaps a better fix would be to change the prototype of pm_qos_update_request to return something so callers can check for success. Lets fix the API rather than use this patch. Please dopt apply it. --mgross -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |