Messages in this thread | | | Date | Thu, 16 Feb 2012 19:55:44 -0800 | Subject | Re: [RFC][PATCH 0/8] PM: Implement autosleep and "wake locks" | From | Arve Hjønnevåg <> |
| |
2012/2/15 Rafael J. Wysocki <rjw@sisk.pl>: > On Wednesday, February 15, 2012, Arve Hjønnevåg wrote: >> 2012/2/14 Rafael J. Wysocki <rjw@sisk.pl>: >> > On Tuesday, February 14, 2012, Arve Hjønnevåg wrote: >> >> On Mon, Feb 6, 2012 at 5:00 PM, Rafael J. Wysocki <rjw@sisk.pl> wrote: >> >> ... >> >> but the wake-source timeout feature has some bugs or incompatible apis. An >> >> init api would also be useful for embedding wake-sources in other data >> >> structures without adding another memory allocation. Your patch to >> >> move the spinlock init to wakeup_source_add still require the struct >> >> to be zero initialized and the name set manually. >> > >> > That should be easy to fix. What about the appended patch? >> > >> >> That works, but I still have to call more than one function before I >> can use the wakeup-source (wakeup_source_init and wakeup_source_add) >> and more than one function before I can free it (__pm_relax, >> wakeup_source_remove and wakeup_source_drop). Is there any reason to >> keep these separate? > > Yes, there is. I think that wakeup_source_create/_destroy() should > use the same initialization functions internally that will be used for > externally allocated wakeup sources (to make sure that all wakeup source > objects are initialized in exactly the same way). >
I agree with that, but is it useful to export these helper functions?
>> Also, not copying the name when the caller provides the memory for the >> wakeup-source would be a closer match to the wakelock api. Most of our >> wakelocks pass a string constant as the name, and making a copy of >> that string is not useful. wake_lock_init is also safe to call from >> atomic context, but I don't know if anyone relies on this. > > OK, below is another go. It doesn't copy the name if wakeup_source_init() is > used (which also does the _add this time). I think, though, that copying > the name is generally safer, because someone might use wakeup_source_init() > with the name string allocated on the stack or otherwise temporary, which would > be a bug with the new version. >
I prefer this version. I have not seen a bug where someone passed a temporary as the wakelock name, I assume since this will show up immediately in the stats file.
-- Arve Hjønnevåg -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |