| Message ID | b759d2563caee1189b543d7a3acb222d316d81a1.1418184737.git.viresh.kumar@linaro.org |
|---|---|
| State | New |
| Headers | show |
On 11 December 2014 at 03:31, Rafael J. Wysocki <rjw@rjwysocki.net> wrote: > I've lost patches [1-2/5] somehow, but never mind. I can get them from Patchwork. Strange, you were always in --to for them .. > In this one I'm wondering about the printk removal mentioned above. Did > checkpatch complain about the printk? commit ebfdc40969f24fc0cdd1349835d36e8ebae05374 Author: Joe Perches <joe@perches.com> Date: Wed Aug 6 16:10:27 2014 -0700 checkpatch: attempt to find unnecessary 'out of memory' messages Logging messages that show some type of "out of memory" error are generally unnecessary as there is a generic message and a stack dump done by the memory subsystem. These messages generally increase kernel size without much added value. Emit a warning on these types of messages. This test looks for any inserted message function, then looks at the previous line for an "if (!foo)" or "if (foo == NULL)" test and then looks at the preceding statement for an allocation function like "foo = kmalloc()" ie: this code matches: foo = kmalloc(); if (foo == NULL) { printk("Out of memory\n"); return -ENOMEM; } This test is very crude and incomplete. This test can miss quite a lot of of OOM messages that do not have this specific form. ie: this code does not match: foo = kmalloc(); if (!foo) { rtn = -ENOMEM; printk("Out of memory!\n"); goto out; } This test could also be a false positive when the logging message itself does not specify anything about memory, but I did not find any false positives in my limited testing. spatch could be a better solution but correctness seems non-trivial for that tool too. -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 12 December 2014 at 02:22, Rafael J. Wysocki <rjw@rjwysocki.net> wrote: > OK > > So I've applied this, but here are the rules for the future regarding > checkpatch.pl: > > (1) checkpatch.pl is meant for checking changes made by a patch and *not* for > checking the existing code. > > (2) Always use common sense on top of checkpatch.pl complaints. Correct, normally I do ignore the warnings for cases which I don't care about. I did react to this one because there have been patches going around removing print messages on allocation failures. And I didn't wanted to get another one for this and so removed it in my patch only.. -- viresh -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/base/power/opp.c b/drivers/base/power/opp.c index 525ffb202d77..1150b9d2e012 100644 --- a/drivers/base/power/opp.c +++ b/drivers/base/power/opp.c @@ -386,6 +386,27 @@ struct dev_pm_opp *dev_pm_opp_find_freq_floor(struct device *dev, } EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_floor); +static struct device_opp *add_device_opp(struct device *dev) +{ + struct device_opp *dev_opp; + + /* + * Allocate a new device OPP table. In the infrequent case where a new + * device is needed to be added, we pay this penalty. + */ + dev_opp = kzalloc(sizeof(*dev_opp), GFP_KERNEL); + if (!dev_opp) + return NULL; + + dev_opp->dev = dev; + srcu_init_notifier_head(&dev_opp->srcu_head); + INIT_LIST_HEAD(&dev_opp->opp_list); + + /* Secure the device list modification */ + list_add_rcu(&dev_opp->node, &dev_opp_list); + return dev_opp; +} + static int dev_pm_opp_add_dynamic(struct device *dev, unsigned long freq, unsigned long u_volt, bool dynamic) { @@ -412,27 +433,13 @@ static int dev_pm_opp_add_dynamic(struct device *dev, unsigned long freq, /* Check for existing list for 'dev' */ dev_opp = find_device_opp(dev); if (IS_ERR(dev_opp)) { - /* - * Allocate a new device OPP table. In the infrequent case - * where a new device is needed to be added, we pay this - * penalty. - */ - dev_opp = kzalloc(sizeof(struct device_opp), GFP_KERNEL); + dev_opp = add_device_opp(dev); if (!dev_opp) { mutex_unlock(&dev_opp_list_lock); kfree(new_opp); - dev_warn(dev, - "%s: Unable to create device OPP structure\n", - __func__); return -ENOMEM; } - dev_opp->dev = dev; - srcu_init_notifier_head(&dev_opp->srcu_head); - INIT_LIST_HEAD(&dev_opp->opp_list); - - /* Secure the device list modification */ - list_add_rcu(&dev_opp->node, &dev_opp_list); head = &dev_opp->opp_list; goto list_add; }
Get the 'device_opp' allocation code into a separate routine to keep only the necessary part in dev_pm_opp_add_dynamic(). Also do s/sizeof(struct device_opp)/sizeof(*dev_opp) and remove the print message on kzalloc() failure as checkpatch warns for that. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> --- drivers/base/power/opp.c | 37 ++++++++++++++++++++++--------------- 1 file changed, 22 insertions(+), 15 deletions(-)