Messages in this thread | | | Subject | Re: [PATCH v2] mm: cma: support sysfs | From | John Hubbard <> | Date | Tue, 9 Feb 2021 23:16:07 -0800 |
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On 2/9/21 11:12 PM, Minchan Kim wrote: ... >>> Agreed. How about this for the warning part? >>> >>> + >>> +/* >>> + * note: kobj_type should provide a release function to free dynamically >>> + * allocated object since kobject is responsible for controlling lifespan >>> + * of the object. However, cma_area is static object so technially, it >>> + * doesn't need release function. It's very exceptional case so pleaes >>> + * do not follow this model. >>> + */ >>> static struct kobj_type cma_ktype = { >>> .sysfs_ops = &kobj_sysfs_ops, >>> .default_groups = cma_groups >>> + .release = NULL, /* do not follow. See above */ >>> }; >>> >> >> No, please no. Just do it the correct way, what is the objection to >> creating a few dynamic kobjects from the heap? How many of these are >> you going to have that it will somehow be "wasteful"? >> >> Please do it properly. > > Oh, I misunderstood your word "don't provide a release function for the > kobject" so thought you agreed on John. If you didn't, we are stuck again: > IIUC, the objection from John was the cma_stat lifetime should be on parent > object, which is reasonable and make code simple. > Frankly speaking, I don't have strong opinion about either approach. > John? >
We should do it as Greg requests, now that it's quite clear that he's insisting on this. Not a big deal.
I just am not especially happy about the inability to do natural, efficient things here, such as use a statically allocated set of things with sysfs. And I remain convinced that the above is not "improper"; it's a reasonable step, given the limitations of the current sysfs design. I just wanted to say that out loud, as my proposal sinks to the bottom of the trench here. haha :)
thanks, -- John Hubbard NVIDIA
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