Message ID | 1371497795-20084-1-git-send-email-shuah.kh@samsung.com (mailing list archive) |
---|---|
State | Changes Requested, archived |
Headers | show |
On Mon, Jun 17, 2013 at 01:36:35PM -0600, Shuah Khan wrote: > Change __device_suspend() path to include driver name and the ops that > get run for a device. This additional information helps associate the > driver and the type of pm_ops the device uses in the suspend path very > quickly, which will aid in debugging problems in suspend and resume paths. > Changed both start and end debug messages to include pm_ops information > and use dev_info() instead of pr_info(). Changed the end message to include > parent device information and have the same format as the start message. > > dmesg output before the change: > > [ 164.390032] calling 1-1+ @ 69, parent: usb1 > [ 164.390035] call 1-1+ returned 0 after 0 usecs > > [ 164.390352] calling 00:0a+ @ 2457, parent: pnp0 > [ 164.390357] call 00:0a+ returned 0 after 3 usecs > > [ 164.390361] calling 00:09+ @ 2457, parent: pnp0 > [ 164.496458] call 00:09+ returned 0 after 103500 usecs > > [ 164.496494] calling 00:05+ @ 2457, parent: pnp0 > [ 164.496511] call 00:05+ returned 0 after 14 usecs > > dmesg output after the change: > > [ 545.985394] usb 1-1: Start: type pm ops @ 68, parent: usb1 > [ 545.987650] usb 1-1: End : type pm ops @ 68, parent: usb1 time(2184 usecs) err(0) > > [ 545.982544] system 00:0a: Start: legacy bus pm ops @ 2391, parent: pnp0 > [ 545.982554] system 00:0a: End : legacy bus pm ops @ 2391, parent: pnp0 time(4 usecs) err(0) > > [ 545.982569] tpm_tis 00:09: Start: legacy bus pm ops @ 2391, parent: pnp0 > [ 546.087017] tpm_tis 00:09: End : legacy bus pm ops @ 2391, parent: pnp0 time(101936 usecs) err(0) > > [ 546.087069] rtc_cmos 00:05: Start: legacy bus pm ops @ 2391, parent: pnp0 > [ 546.087084] rtc_cmos 00:05: End : legacy bus pm ops @ 2391, parent: pnp0 time(11 usecs) err(0) > > Signed-off-by: Shuah Khan <shuah.kh@samsung.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> -- 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 Mon, 17 Jun 2013, Shuah Khan wrote: > Change __device_suspend() path to include driver name and the ops that > get run for a device. This additional information helps associate the > driver and the type of pm_ops the device uses in the suspend path very > quickly, which will aid in debugging problems in suspend and resume paths. > Changed both start and end debug messages to include pm_ops information > and use dev_info() instead of pr_info(). Changed the end message to include > parent device information and have the same format as the start message. > > dmesg output before the change: > > [ 164.390032] calling 1-1+ @ 69, parent: usb1 > [ 164.390035] call 1-1+ returned 0 after 0 usecs > > [ 164.390352] calling 00:0a+ @ 2457, parent: pnp0 > [ 164.390357] call 00:0a+ returned 0 after 3 usecs > > [ 164.390361] calling 00:09+ @ 2457, parent: pnp0 > [ 164.496458] call 00:09+ returned 0 after 103500 usecs > > [ 164.496494] calling 00:05+ @ 2457, parent: pnp0 > [ 164.496511] call 00:05+ returned 0 after 14 usecs > > dmesg output after the change: > > [ 545.985394] usb 1-1: Start: type pm ops @ 68, parent: usb1 > [ 545.987650] usb 1-1: End : type pm ops @ 68, parent: usb1 time(2184 usecs) err(0) > > [ 545.982544] system 00:0a: Start: legacy bus pm ops @ 2391, parent: pnp0 > [ 545.982554] system 00:0a: End : legacy bus pm ops @ 2391, parent: pnp0 time(4 usecs) err(0) > > [ 545.982569] tpm_tis 00:09: Start: legacy bus pm ops @ 2391, parent: pnp0 > [ 546.087017] tpm_tis 00:09: End : legacy bus pm ops @ 2391, parent: pnp0 time(101936 usecs) err(0) > > [ 546.087069] rtc_cmos 00:05: Start: legacy bus pm ops @ 2391, parent: pnp0 > [ 546.087084] rtc_cmos 00:05: End : legacy bus pm ops @ 2391, parent: pnp0 time(11 usecs) err(0) If you don't mind a little more bike-shedding, I suggest formatting the return value and time in a shorter format, like this: [ 545.987650] usb 1-1: End : type pm ops @ 68, parent: usb1 -> 0, 2184 us Alan Stern -- 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 06/17/2013 02:24 PM, Alan Stern wrote: > On Mon, 17 Jun 2013, Shuah Khan wrote: > >> Change __device_suspend() path to include driver name and the ops that >> get run for a device. This additional information helps associate the >> driver and the type of pm_ops the device uses in the suspend path very >> quickly, which will aid in debugging problems in suspend and resume paths. >> Changed both start and end debug messages to include pm_ops information >> and use dev_info() instead of pr_info(). Changed the end message to include >> parent device information and have the same format as the start message. >> >> >> [ 546.087069] rtc_cmos 00:05: Start: legacy bus pm ops @ 2391, parent: pnp0 >> [ 546.087084] rtc_cmos 00:05: End : legacy bus pm ops @ 2391, parent: pnp0 time(11 usecs) err(0) > > If you don't mind a little more bike-shedding, I suggest formatting the > return value and time in a shorter format, like this: > > [ 545.987650] usb 1-1: End : type pm ops @ 68, parent: usb1 -> 0, 2184 us > > Alan Stern > > I am leaning towards leaving it the way it is for clarity, even though it is a bit longer? Changing it would make it too cryptic especially error return. thanks, -- Shuah Shuah Khan, Linux Kernel Developer - Open Source Group Samsung Research America (Silicon Valley) shuah.kh@samsung.com | (970) 672-0658 -- 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 Monday, June 17, 2013 01:36:35 PM Shuah Khan wrote: > Change __device_suspend() path to include driver name and the ops that > get run for a device. This additional information helps associate the > driver and the type of pm_ops the device uses in the suspend path very > quickly, which will aid in debugging problems in suspend and resume paths. > Changed both start and end debug messages to include pm_ops information > and use dev_info() instead of pr_info(). Changed the end message to include > parent device information and have the same format as the start message. > > dmesg output before the change: > > [ 164.390032] calling 1-1+ @ 69, parent: usb1 > [ 164.390035] call 1-1+ returned 0 after 0 usecs > > [ 164.390352] calling 00:0a+ @ 2457, parent: pnp0 > [ 164.390357] call 00:0a+ returned 0 after 3 usecs > > [ 164.390361] calling 00:09+ @ 2457, parent: pnp0 > [ 164.496458] call 00:09+ returned 0 after 103500 usecs > > [ 164.496494] calling 00:05+ @ 2457, parent: pnp0 > [ 164.496511] call 00:05+ returned 0 after 14 usecs > > dmesg output after the change: > > [ 545.985394] usb 1-1: Start: type pm ops @ 68, parent: usb1 > [ 545.987650] usb 1-1: End : type pm ops @ 68, parent: usb1 time(2184 usecs) err(0) > > [ 545.982544] system 00:0a: Start: legacy bus pm ops @ 2391, parent: pnp0 > [ 545.982554] system 00:0a: End : legacy bus pm ops @ 2391, parent: pnp0 time(4 usecs) err(0) > > [ 545.982569] tpm_tis 00:09: Start: legacy bus pm ops @ 2391, parent: pnp0 > [ 546.087017] tpm_tis 00:09: End : legacy bus pm ops @ 2391, parent: pnp0 time(101936 usecs) err(0) > > [ 546.087069] rtc_cmos 00:05: Start: legacy bus pm ops @ 2391, parent: pnp0 > [ 546.087084] rtc_cmos 00:05: End : legacy bus pm ops @ 2391, parent: pnp0 time(11 usecs) err(0) > I was about to apply your patch, but then I noticed something that might cause problems to happen. Namely, there are tools that use these messages to create suspend/resume time charts and they will stop working after the proposed changes. Please keep the existing formatting the way it is and only append the additional information at the end of each line. Thanks, Rafael > Signed-off-by: Shuah Khan <shuah.kh@samsung.com> > --- > > v2: Change to use dev_info() instead of pr_info() > v3: Change to add parent info to debug_report and make start and end messages > look similar have a tighter association. > > drivers/base/power/main.c | 49 +++++++++++++++++++++++++++------------------ > 1 file changed, 29 insertions(+), 20 deletions(-) > > diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c > index 5a9b656..c2132b8 100644 > --- a/drivers/base/power/main.c > +++ b/drivers/base/power/main.c > @@ -157,13 +157,14 @@ void device_pm_move_last(struct device *dev) > list_move_tail(&dev->power.entry, &dpm_list); > } > > -static ktime_t initcall_debug_start(struct device *dev) > +static ktime_t initcall_debug_start(struct device *dev, char *info) > { > ktime_t calltime = ktime_set(0, 0); > > if (pm_print_times_enabled) { > - pr_info("calling %s+ @ %i, parent: %s\n", > - dev_name(dev), task_pid_nr(current), > + /* string in info has an extra space at the end */ > + dev_info(dev, "Start: %s@ %i, parent: %s\n", > + info, task_pid_nr(current), > dev->parent ? dev_name(dev->parent) : "none"); > calltime = ktime_get(); > } > @@ -172,15 +173,19 @@ static ktime_t initcall_debug_start(struct device *dev) > } > > static void initcall_debug_report(struct device *dev, ktime_t calltime, > - int error) > + int error, char *info) > { > ktime_t delta, rettime; > > if (pm_print_times_enabled) { > rettime = ktime_get(); > delta = ktime_sub(rettime, calltime); > - pr_info("call %s+ returned %d after %Ld usecs\n", dev_name(dev), > - error, (unsigned long long)ktime_to_ns(delta) >> 10); > + /* string in info has an extra space at the end */ > + dev_info(dev, > + "End : %s@ %i, parent: %s time(%llu usecs) err(%d)\n", > + info, task_pid_nr(current), > + dev->parent ? dev_name(dev->parent) : "none", > + (unsigned long long)ktime_to_ns(delta) >> 10, error); > } > } > > @@ -373,13 +378,13 @@ static int dpm_run_callback(pm_callback_t cb, struct device *dev, > if (!cb) > return 0; > > - calltime = initcall_debug_start(dev); > + calltime = initcall_debug_start(dev, info); > > pm_dev_dbg(dev, state, info); > error = cb(dev); > suspend_report_result(cb, error); > > - initcall_debug_report(dev, calltime, error); > + initcall_debug_report(dev, calltime, error, info); > > return error; > } > @@ -1027,17 +1032,19 @@ EXPORT_SYMBOL_GPL(dpm_suspend_end); > * @cb: Suspend callback to execute. > */ > static int legacy_suspend(struct device *dev, pm_message_t state, > - int (*cb)(struct device *dev, pm_message_t state)) > + int (*cb)(struct device *dev, pm_message_t state), > + char *info) > { > int error; > ktime_t calltime; > > - calltime = initcall_debug_start(dev); > + calltime = initcall_debug_start(dev, info); > > + pm_dev_dbg(dev, state, info); > error = cb(dev, state); > suspend_report_result(cb, error); > > - initcall_debug_report(dev, calltime, error); > + initcall_debug_report(dev, calltime, error, info); > > return error; > } > @@ -1079,43 +1086,45 @@ static int __device_suspend(struct device *dev, pm_message_t state, bool async) > device_lock(dev); > > if (dev->pm_domain) { > - info = "power domain "; > + info = "power domain pm ops "; > callback = pm_op(&dev->pm_domain->ops, state); > goto Run; > } > > if (dev->type && dev->type->pm) { > - info = "type "; > + info = "type pm ops "; > callback = pm_op(dev->type->pm, state); > goto Run; > } > > if (dev->class) { > if (dev->class->pm) { > - info = "class "; > + info = "class pm ops "; > callback = pm_op(dev->class->pm, state); > goto Run; > } else if (dev->class->suspend) { > - pm_dev_dbg(dev, state, "legacy class "); > - error = legacy_suspend(dev, state, dev->class->suspend); > + info = "legacy class pm ops "; > + error = legacy_suspend(dev, state, dev->class->suspend, > + info); > goto End; > } > } > > if (dev->bus) { > if (dev->bus->pm) { > - info = "bus "; > + info = "bus pm ops "; > callback = pm_op(dev->bus->pm, state); > } else if (dev->bus->suspend) { > - pm_dev_dbg(dev, state, "legacy bus "); > - error = legacy_suspend(dev, state, dev->bus->suspend); > + info = "legacy bus pm ops "; > + error = legacy_suspend(dev, state, dev->bus->suspend, > + info); > goto End; > } > } > > Run: > if (!callback && dev->driver && dev->driver->pm) { > - info = "driver "; > + info = "driver pm ops "; > callback = pm_op(dev->driver->pm, state); > } > >
On 06/21/2013 06:15 PM, Rafael J. Wysocki wrote: > On Monday, June 17, 2013 01:36:35 PM Shuah Khan wrote: >> Change __device_suspend() path to include driver name and the ops that >> get run for a device. This additional information helps associate the >> driver and the type of pm_ops the device uses in the suspend path very >> quickly, which will aid in debugging problems in suspend and resume paths. >> Changed both start and end debug messages to include pm_ops information >> and use dev_info() instead of pr_info(). Changed the end message to include >> parent device information and have the same format as the start message. >> >> dmesg output before the change: >> >> [ 164.390032] calling 1-1+ @ 69, parent: usb1 >> [ 164.390035] call 1-1+ returned 0 after 0 usecs >> >> [ 164.390352] calling 00:0a+ @ 2457, parent: pnp0 >> [ 164.390357] call 00:0a+ returned 0 after 3 usecs >> >> [ 164.390361] calling 00:09+ @ 2457, parent: pnp0 >> [ 164.496458] call 00:09+ returned 0 after 103500 usecs >> >> [ 164.496494] calling 00:05+ @ 2457, parent: pnp0 >> [ 164.496511] call 00:05+ returned 0 after 14 usecs >> >> dmesg output after the change: >> >> [ 545.985394] usb 1-1: Start: type pm ops @ 68, parent: usb1 >> [ 545.987650] usb 1-1: End : type pm ops @ 68, parent: usb1 time(2184 usecs) err(0) >> >> [ 545.982544] system 00:0a: Start: legacy bus pm ops @ 2391, parent: pnp0 >> [ 545.982554] system 00:0a: End : legacy bus pm ops @ 2391, parent: pnp0 time(4 usecs) err(0) >> >> [ 545.982569] tpm_tis 00:09: Start: legacy bus pm ops @ 2391, parent: pnp0 >> [ 546.087017] tpm_tis 00:09: End : legacy bus pm ops @ 2391, parent: pnp0 time(101936 usecs) err(0) >> >> [ 546.087069] rtc_cmos 00:05: Start: legacy bus pm ops @ 2391, parent: pnp0 >> [ 546.087084] rtc_cmos 00:05: End : legacy bus pm ops @ 2391, parent: pnp0 time(11 usecs) err(0) >> > > I was about to apply your patch, but then I noticed something that might cause > problems to happen. > > Namely, there are tools that use these messages to create suspend/resume time > charts and they will stop working after the proposed changes. > > Please keep the existing formatting the way it is and only append the additional > information at the end of each line. > > Thanks, > Rafael > Hi Rafael, Yes changing the format would cause problems for scripts that rely on the exact format. Would you like to pick the v2 version of the patch that appends the additional information at the end, instead of changing the format? Here is the link. If you would like me to resend it, I can do that. https://lkml.org/lkml/2013/6/14/448 -- Shuah Shuah Khan, Linux Kernel Developer - Open Source Group Samsung Research America (Silicon Valley) shuah.kh@samsung.com | (970) 672-0658 -- 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 Sat, 2013-06-22 at 02:24 +0200, Rafael J. Wysocki wrote: > Namely, there are tools that use these messages to create suspend/resume time > charts and they will stop working after the proposed changes. dmesg output isn't guaranteed to be stable. -- 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 Friday, June 21, 2013 07:27:22 PM Joe Perches wrote: > On Sat, 2013-06-22 at 02:24 +0200, Rafael J. Wysocki wrote: > > Namely, there are tools that use these messages to create suspend/resume time > > charts and they will stop working after the proposed changes. > > dmesg output isn't guaranteed to be stable. So? -- 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 Sat, 2013-06-22 at 21:52 +0200, Rafael J. Wysocki wrote: > On Friday, June 21, 2013 07:27:22 PM Joe Perches wrote: > > On Sat, 2013-06-22 at 02:24 +0200, Rafael J. Wysocki wrote: > > > Namely, there are tools that use these messages to create suspend/resume time > > > charts and they will stop working after the proposed changes. > > > > dmesg output isn't guaranteed to be stable. > > So? So even if new information was only appended to the existing line, the script could break. If any script needs something stable it should depend on information available through other sources like trace or proc or sysfs. Tools that use dmesg should adapt to whatever gets thrown at it and handle the output from whatever kernel versions the script supports. For instance, what happens to the script when console_level is set to 1? Requiring that no one can change a dmesg to add or improve the content for readability or intelligibility I think unreasonable. -- 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 Sat 2013-06-22 18:05:50, Joe Perches wrote: > On Sat, 2013-06-22 at 21:52 +0200, Rafael J. Wysocki wrote: > > On Friday, June 21, 2013 07:27:22 PM Joe Perches wrote: > > > On Sat, 2013-06-22 at 02:24 +0200, Rafael J. Wysocki wrote: > > > > Namely, there are tools that use these messages to create suspend/resume time > > > > charts and they will stop working after the proposed changes. > > > > > > dmesg output isn't guaranteed to be stable. > > > > So? > > So even if new information was only appended to > the existing line, the script could break. > > If any script needs something stable it should > depend on information available through other > sources like trace or proc or sysfs. Yeah, people try to add it to debugfs, and the results were not nice. dmesg output is not stable, but we should not break it unneccessarily; appending at the end should be fine. Pavel
On Sun, 2013-06-23 at 12:07 +0200, Rafael J. Wysocki wrote: > On Saturday, June 22, 2013 06:05:50 PM Joe Perches wrote: > > If any script needs something stable it should > > depend on information available through other > > sources like trace or proc or sysfs. > > That is clearly impossible in this particular case, though. Why couldn't this printk be converted into an equivalent tracepoint? -- 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 Saturday, June 22, 2013 06:05:50 PM Joe Perches wrote: > On Sat, 2013-06-22 at 21:52 +0200, Rafael J. Wysocki wrote: > > On Friday, June 21, 2013 07:27:22 PM Joe Perches wrote: > > > On Sat, 2013-06-22 at 02:24 +0200, Rafael J. Wysocki wrote: > > > > Namely, there are tools that use these messages to create suspend/resume time > > > > charts and they will stop working after the proposed changes. > > > > > > dmesg output isn't guaranteed to be stable. > > > > So? > > So even if new information was only appended to > the existing line, the script could break. In this particular case, if it is written sanely, it won't. > If any script needs something stable it should > depend on information available through other > sources like trace or proc or sysfs. That is clearly impossible in this particular case, though. > Tools that use dmesg should adapt to whatever gets > thrown at it and handle the output from whatever > kernel versions the script supports. > > For instance, what happens to the script when > console_level is set to 1? You know, these particular messages are not printed without initcall_debug in the command line and the people who use them for diagnostics usually generate them on purpose and *then* feed the log to the script (or tool). > Requiring that no one can change a dmesg to > add or improve the content for readability > or intelligibility I think unreasonable. In general, you'd be right, but this is not a general case. Thanks, Rafael
On Sun, 2013-06-23 at 12:22 +0200, Rafael J. Wysocki wrote: > On Sunday, June 23, 2013 03:03:31 AM Joe Perches wrote: > > On Sun, 2013-06-23 at 12:07 +0200, Rafael J. Wysocki wrote: > > > On Saturday, June 22, 2013 06:05:50 PM Joe Perches wrote: > > > > If any script needs something stable it should > > > > depend on information available through other > > > > sources like trace or proc or sysfs. > > > > > > That is clearly impossible in this particular case, though. > > > > Why couldn't this printk be converted into an equivalent tracepoint? > > Well, why wouldn't you try to do that? Why should I? -- 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 Sunday, June 23, 2013 03:03:31 AM Joe Perches wrote: > On Sun, 2013-06-23 at 12:07 +0200, Rafael J. Wysocki wrote: > > On Saturday, June 22, 2013 06:05:50 PM Joe Perches wrote: > > > If any script needs something stable it should > > > depend on information available through other > > > sources like trace or proc or sysfs. > > > > That is clearly impossible in this particular case, though. > > Why couldn't this printk be converted into an equivalent tracepoint? Well, why wouldn't you try to do that? Rafael -- 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 Sunday, June 23, 2013 03:16:30 AM Joe Perches wrote: > On Sun, 2013-06-23 at 12:22 +0200, Rafael J. Wysocki wrote: > > On Sunday, June 23, 2013 03:03:31 AM Joe Perches wrote: > > > On Sun, 2013-06-23 at 12:07 +0200, Rafael J. Wysocki wrote: > > > > On Saturday, June 22, 2013 06:05:50 PM Joe Perches wrote: > > > > > If any script needs something stable it should > > > > > depend on information available through other > > > > > sources like trace or proc or sysfs. > > > > > > > > That is clearly impossible in this particular case, though. > > > > > > Why couldn't this printk be converted into an equivalent tracepoint? > > > > Well, why wouldn't you try to do that? > > Why should I? Because you're arguing that it should be done. If you think that it's better to use tracepoints here, please implement those tracepoints and show everyone that they are really better than what we have. Till then, we'll use what's already there. Thanks, Rafael -- 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 Sun, 2013-06-23 at 12:35 +0200, Rafael J. Wysocki wrote: > On Sunday, June 23, 2013 03:16:30 AM Joe Perches wrote: > > On Sun, 2013-06-23 at 12:22 +0200, Rafael J. Wysocki wrote: > > > On Sunday, June 23, 2013 03:03:31 AM Joe Perches wrote: > > > > On Sun, 2013-06-23 at 12:07 +0200, Rafael J. Wysocki wrote: > > > > > On Saturday, June 22, 2013 06:05:50 PM Joe Perches wrote: > > > > > > If any script needs something stable it should > > > > > > depend on information available through other > > > > > > sources like trace or proc or sysfs. > > > > > > > > > > That is clearly impossible in this particular case, though. > > > > > > > > Why couldn't this printk be converted into an equivalent tracepoint? > > > > > > Well, why wouldn't you try to do that? > > > > Why should I? > > Because you're arguing that it should be done. > > If you think that it's better to use tracepoints here, please implement those > tracepoints and show everyone that they are really better than what we have. Nope, you're arguing that dmesg output, known to be non-stable, should not have this particular message changed. You stated "<it's> clearly impossible". I do dispute that. If you need something stable, you shouldn't use dmesg, That's a simple statement, not anything else. Right now, I don't care if this particular message changes. I'm not doing any PM testing or timing at the moment. > Till then, we'll use what's already there. Fine by me. It's up to Shuah Khan to get a patch accepted. cheers, Joe -- 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 Sunday, June 23, 2013 03:41:20 AM Joe Perches wrote: > On Sun, 2013-06-23 at 12:35 +0200, Rafael J. Wysocki wrote: > > On Sunday, June 23, 2013 03:16:30 AM Joe Perches wrote: > > > On Sun, 2013-06-23 at 12:22 +0200, Rafael J. Wysocki wrote: > > > > On Sunday, June 23, 2013 03:03:31 AM Joe Perches wrote: > > > > > On Sun, 2013-06-23 at 12:07 +0200, Rafael J. Wysocki wrote: > > > > > > On Saturday, June 22, 2013 06:05:50 PM Joe Perches wrote: > > > > > > > If any script needs something stable it should > > > > > > > depend on information available through other > > > > > > > sources like trace or proc or sysfs. > > > > > > > > > > > > That is clearly impossible in this particular case, though. > > > > > > > > > > Why couldn't this printk be converted into an equivalent tracepoint? > > > > > > > > Well, why wouldn't you try to do that? > > > > > > Why should I? > > > > Because you're arguing that it should be done. > > > > If you think that it's better to use tracepoints here, please implement those > > tracepoints and show everyone that they are really better than what we have. > > Nope, you're arguing that dmesg output, known to be non-stable, > should not have this particular message changed. > > You stated "<it's> clearly impossible". I do dispute that. And what I meant by that was "there are no tracepoints, sysfs attributes etc. those tools can use to get the information they need". Which is a fact of life. > If you need something stable, you shouldn't use dmesg, > That's a simple statement, not anything else. > > Right now, I don't care if this particular message changes. > I'm not doing any PM testing or timing at the moment. > > > Till then, we'll use what's already there. > > Fine by me. It's up to Shuah Khan to get a patch accepted. Well, precisely. Thanks, Rafael
On Sun, 2013-06-23 at 13:36 +0200, Rafael J. Wysocki wrote: > Please keep the existing format as is literally and append any > new information to the end of the line. Hi Shuah. Perhaps the better long-term approach would be to add a new tracepoint 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 Saturday, June 22, 2013 12:58:28 AM Shuah Khan wrote: > On 06/21/2013 06:15 PM, Rafael J. Wysocki wrote: > > On Monday, June 17, 2013 01:36:35 PM Shuah Khan wrote: > >> Change __device_suspend() path to include driver name and the ops that > >> get run for a device. This additional information helps associate the > >> driver and the type of pm_ops the device uses in the suspend path very > >> quickly, which will aid in debugging problems in suspend and resume paths. > >> Changed both start and end debug messages to include pm_ops information > >> and use dev_info() instead of pr_info(). Changed the end message to include > >> parent device information and have the same format as the start message. > >> > >> dmesg output before the change: > >> > >> [ 164.390032] calling 1-1+ @ 69, parent: usb1 > >> [ 164.390035] call 1-1+ returned 0 after 0 usecs > >> > >> [ 164.390352] calling 00:0a+ @ 2457, parent: pnp0 > >> [ 164.390357] call 00:0a+ returned 0 after 3 usecs > >> > >> [ 164.390361] calling 00:09+ @ 2457, parent: pnp0 > >> [ 164.496458] call 00:09+ returned 0 after 103500 usecs > >> > >> [ 164.496494] calling 00:05+ @ 2457, parent: pnp0 > >> [ 164.496511] call 00:05+ returned 0 after 14 usecs > >> > >> dmesg output after the change: > >> > >> [ 545.985394] usb 1-1: Start: type pm ops @ 68, parent: usb1 > >> [ 545.987650] usb 1-1: End : type pm ops @ 68, parent: usb1 time(2184 usecs) err(0) > >> > >> [ 545.982544] system 00:0a: Start: legacy bus pm ops @ 2391, parent: pnp0 > >> [ 545.982554] system 00:0a: End : legacy bus pm ops @ 2391, parent: pnp0 time(4 usecs) err(0) > >> > >> [ 545.982569] tpm_tis 00:09: Start: legacy bus pm ops @ 2391, parent: pnp0 > >> [ 546.087017] tpm_tis 00:09: End : legacy bus pm ops @ 2391, parent: pnp0 time(101936 usecs) err(0) > >> > >> [ 546.087069] rtc_cmos 00:05: Start: legacy bus pm ops @ 2391, parent: pnp0 > >> [ 546.087084] rtc_cmos 00:05: End : legacy bus pm ops @ 2391, parent: pnp0 time(11 usecs) err(0) > >> > > > > I was about to apply your patch, but then I noticed something that might cause > > problems to happen. > > > > Namely, there are tools that use these messages to create suspend/resume time > > charts and they will stop working after the proposed changes. > > > > Please keep the existing formatting the way it is and only append the additional > > information at the end of each line. > > > > Thanks, > > Rafael > > > > Hi Rafael, Hi, > Yes changing the format would cause problems for scripts that rely on > the exact format. Would you like to pick the v2 version of the patch > that appends the additional information at the end, instead of changing > the format? Here is the link. If you would like me to resend it, I can > do that. > > https://lkml.org/lkml/2013/6/14/448 Well, this one replaces pr_info() with dev_info() and the format changes as a result. Please keep the existing format as is literally and append any new information to the end of the line. Thanks, Rafael
On Sunday, June 23, 2013 04:34:17 AM Joe Perches wrote: > On Sun, 2013-06-23 at 13:36 +0200, Rafael J. Wysocki wrote: > > Please keep the existing format as is literally and append any > > new information to the end of the line. > > Hi Shuah. > > Perhaps the better long-term approach would be to add > a new tracepoint too. In fact, I would even prefer it if new tracepoints were added so that we could deprecate the dmesg messages at one point in the future. Thanks, Rafael
On 06/23/2013 03:49 PM, Rafael J. Wysocki wrote: > On Sunday, June 23, 2013 04:34:17 AM Joe Perches wrote: >> On Sun, 2013-06-23 at 13:36 +0200, Rafael J. Wysocki wrote: >>> Please keep the existing format as is literally and append any >>> new information to the end of the line. >> >> Hi Shuah. >> >> Perhaps the better long-term approach would be to add >> a new tracepoint too. > > In fact, I would even prefer it if new tracepoints were added so that we > could deprecate the dmesg messages at one point in the future. > > Thanks, > Rafael > > Rafael/Joe, I can work on adding a tracepoint. Do you want to take the v2 patch in the meantime? -- Shuah Shuah Khan, Linux Kernel Developer - Open Source Group Samsung Research America (Silicon Valley) shuah.kh@samsung.com | (970) 672-0658 -- 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 06/24/2013 10:25 AM, Shuah Khan wrote: > On 06/23/2013 03:49 PM, Rafael J. Wysocki wrote: >> On Sunday, June 23, 2013 04:34:17 AM Joe Perches wrote: >>> On Sun, 2013-06-23 at 13:36 +0200, Rafael J. Wysocki wrote: >>>> Please keep the existing format as is literally and append any >>>> new information to the end of the line. >>> >>> Hi Shuah. >>> >>> Perhaps the better long-term approach would be to add >>> a new tracepoint too. >> >> In fact, I would even prefer it if new tracepoints were added so that we >> could deprecate the dmesg messages at one point in the future. >> >> Thanks, >> Rafael >> >> > > Rafael/Joe, > > I can work on adding a tracepoint. Do you want to take the v2 patch in > the meantime? > Rafael, ok. Caught up with the entire thread. v2 patch uses dev_info() and hence same concern about format change applies to that one as well. Do you want to take the v1 patch that didn't change the format and just added the additional information at the end? https://lkml.org/lkml/2013/6/14/330 -- Shuah Shuah Khan, Linux Kernel Developer - Open Source Group Samsung Research America (Silicon Valley) shuah.kh@samsung.com | (970) 672-0658 -- 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 Monday, June 24, 2013 04:37:28 PM Shuah Khan wrote: > On 06/24/2013 10:25 AM, Shuah Khan wrote: > > On 06/23/2013 03:49 PM, Rafael J. Wysocki wrote: > >> On Sunday, June 23, 2013 04:34:17 AM Joe Perches wrote: > >>> On Sun, 2013-06-23 at 13:36 +0200, Rafael J. Wysocki wrote: > >>>> Please keep the existing format as is literally and append any > >>>> new information to the end of the line. > >>> > >>> Hi Shuah. > >>> > >>> Perhaps the better long-term approach would be to add > >>> a new tracepoint too. > >> > >> In fact, I would even prefer it if new tracepoints were added so that we > >> could deprecate the dmesg messages at one point in the future. > >> > >> Thanks, > >> Rafael > >> > >> > > > > Rafael/Joe, > > > > I can work on adding a tracepoint. Do you want to take the v2 patch in > > the meantime? > > > > Rafael, > > ok. Caught up with the entire thread. v2 patch uses dev_info() and hence > same concern about format change applies to that one as well. > > Do you want to take the v1 patch that didn't change the format and just > added the additional information at the end? Well, if you're going to work on the tracepoints, I'll rather not take this at all. Thanks, Rafael
On 06/24/2013 01:35 PM, Rafael J. Wysocki wrote: > On Monday, June 24, 2013 04:37:28 PM Shuah Khan wrote: >> On 06/24/2013 10:25 AM, Shuah Khan wrote: >>> On 06/23/2013 03:49 PM, Rafael J. Wysocki wrote: >>>> On Sunday, June 23, 2013 04:34:17 AM Joe Perches wrote: >>>>> On Sun, 2013-06-23 at 13:36 +0200, Rafael J. Wysocki wrote: >>>>>> Please keep the existing format as is literally and append any >>>>>> new information to the end of the line. >>>>> >>>>> Hi Shuah. >>>>> >>>>> Perhaps the better long-term approach would be to add >>>>> a new tracepoint too. >>>> >>>> In fact, I would even prefer it if new tracepoints were added so that we >>>> could deprecate the dmesg messages at one point in the future. >>>> >>>> Thanks, >>>> Rafael >>>> >>>> >>> >>> Rafael/Joe, >>> >>> I can work on adding a tracepoint. Do you want to take the v2 patch in >>> the meantime? >>> >> >> Rafael, >> >> ok. Caught up with the entire thread. v2 patch uses dev_info() and hence >> same concern about format change applies to that one as well. >> >> Do you want to take the v1 patch that didn't change the format and just >> added the additional information at the end? > > Well, if you're going to work on the tracepoints, I'll rather not take this > at all. > > Thanks, > Rafael > > Makes sense. Yes I am going to start work on tracepoints then. -- Shuah Shuah Khan, Linux Kernel Developer - Open Source Group Samsung Research America (Silicon Valley) shuah.kh@samsung.com | (970) 672-0658 -- 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/main.c b/drivers/base/power/main.c index 5a9b656..c2132b8 100644 --- a/drivers/base/power/main.c +++ b/drivers/base/power/main.c @@ -157,13 +157,14 @@ void device_pm_move_last(struct device *dev) list_move_tail(&dev->power.entry, &dpm_list); } -static ktime_t initcall_debug_start(struct device *dev) +static ktime_t initcall_debug_start(struct device *dev, char *info) { ktime_t calltime = ktime_set(0, 0); if (pm_print_times_enabled) { - pr_info("calling %s+ @ %i, parent: %s\n", - dev_name(dev), task_pid_nr(current), + /* string in info has an extra space at the end */ + dev_info(dev, "Start: %s@ %i, parent: %s\n", + info, task_pid_nr(current), dev->parent ? dev_name(dev->parent) : "none"); calltime = ktime_get(); } @@ -172,15 +173,19 @@ static ktime_t initcall_debug_start(struct device *dev) } static void initcall_debug_report(struct device *dev, ktime_t calltime, - int error) + int error, char *info) { ktime_t delta, rettime; if (pm_print_times_enabled) { rettime = ktime_get(); delta = ktime_sub(rettime, calltime); - pr_info("call %s+ returned %d after %Ld usecs\n", dev_name(dev), - error, (unsigned long long)ktime_to_ns(delta) >> 10); + /* string in info has an extra space at the end */ + dev_info(dev, + "End : %s@ %i, parent: %s time(%llu usecs) err(%d)\n", + info, task_pid_nr(current), + dev->parent ? dev_name(dev->parent) : "none", + (unsigned long long)ktime_to_ns(delta) >> 10, error); } } @@ -373,13 +378,13 @@ static int dpm_run_callback(pm_callback_t cb, struct device *dev, if (!cb) return 0; - calltime = initcall_debug_start(dev); + calltime = initcall_debug_start(dev, info); pm_dev_dbg(dev, state, info); error = cb(dev); suspend_report_result(cb, error); - initcall_debug_report(dev, calltime, error); + initcall_debug_report(dev, calltime, error, info); return error; } @@ -1027,17 +1032,19 @@ EXPORT_SYMBOL_GPL(dpm_suspend_end); * @cb: Suspend callback to execute. */ static int legacy_suspend(struct device *dev, pm_message_t state, - int (*cb)(struct device *dev, pm_message_t state)) + int (*cb)(struct device *dev, pm_message_t state), + char *info) { int error; ktime_t calltime; - calltime = initcall_debug_start(dev); + calltime = initcall_debug_start(dev, info); + pm_dev_dbg(dev, state, info); error = cb(dev, state); suspend_report_result(cb, error); - initcall_debug_report(dev, calltime, error); + initcall_debug_report(dev, calltime, error, info); return error; } @@ -1079,43 +1086,45 @@ static int __device_suspend(struct device *dev, pm_message_t state, bool async) device_lock(dev); if (dev->pm_domain) { - info = "power domain "; + info = "power domain pm ops "; callback = pm_op(&dev->pm_domain->ops, state); goto Run; } if (dev->type && dev->type->pm) { - info = "type "; + info = "type pm ops "; callback = pm_op(dev->type->pm, state); goto Run; } if (dev->class) { if (dev->class->pm) { - info = "class "; + info = "class pm ops "; callback = pm_op(dev->class->pm, state); goto Run; } else if (dev->class->suspend) { - pm_dev_dbg(dev, state, "legacy class "); - error = legacy_suspend(dev, state, dev->class->suspend); + info = "legacy class pm ops "; + error = legacy_suspend(dev, state, dev->class->suspend, + info); goto End; } } if (dev->bus) { if (dev->bus->pm) { - info = "bus "; + info = "bus pm ops "; callback = pm_op(dev->bus->pm, state); } else if (dev->bus->suspend) { - pm_dev_dbg(dev, state, "legacy bus "); - error = legacy_suspend(dev, state, dev->bus->suspend); + info = "legacy bus pm ops "; + error = legacy_suspend(dev, state, dev->bus->suspend, + info); goto End; } } Run: if (!callback && dev->driver && dev->driver->pm) { - info = "driver "; + info = "driver pm ops "; callback = pm_op(dev->driver->pm, state); }
Change __device_suspend() path to include driver name and the ops that get run for a device. This additional information helps associate the driver and the type of pm_ops the device uses in the suspend path very quickly, which will aid in debugging problems in suspend and resume paths. Changed both start and end debug messages to include pm_ops information and use dev_info() instead of pr_info(). Changed the end message to include parent device information and have the same format as the start message. dmesg output before the change: [ 164.390032] calling 1-1+ @ 69, parent: usb1 [ 164.390035] call 1-1+ returned 0 after 0 usecs [ 164.390352] calling 00:0a+ @ 2457, parent: pnp0 [ 164.390357] call 00:0a+ returned 0 after 3 usecs [ 164.390361] calling 00:09+ @ 2457, parent: pnp0 [ 164.496458] call 00:09+ returned 0 after 103500 usecs [ 164.496494] calling 00:05+ @ 2457, parent: pnp0 [ 164.496511] call 00:05+ returned 0 after 14 usecs dmesg output after the change: [ 545.985394] usb 1-1: Start: type pm ops @ 68, parent: usb1 [ 545.987650] usb 1-1: End : type pm ops @ 68, parent: usb1 time(2184 usecs) err(0) [ 545.982544] system 00:0a: Start: legacy bus pm ops @ 2391, parent: pnp0 [ 545.982554] system 00:0a: End : legacy bus pm ops @ 2391, parent: pnp0 time(4 usecs) err(0) [ 545.982569] tpm_tis 00:09: Start: legacy bus pm ops @ 2391, parent: pnp0 [ 546.087017] tpm_tis 00:09: End : legacy bus pm ops @ 2391, parent: pnp0 time(101936 usecs) err(0) [ 546.087069] rtc_cmos 00:05: Start: legacy bus pm ops @ 2391, parent: pnp0 [ 546.087084] rtc_cmos 00:05: End : legacy bus pm ops @ 2391, parent: pnp0 time(11 usecs) err(0) Signed-off-by: Shuah Khan <shuah.kh@samsung.com> --- v2: Change to use dev_info() instead of pr_info() v3: Change to add parent info to debug_report and make start and end messages look similar have a tighter association. drivers/base/power/main.c | 49 +++++++++++++++++++++++++++------------------ 1 file changed, 29 insertions(+), 20 deletions(-)