Hi Dan, On 05/11/2012 08:50 AM, Dan Magenheimer wrote: >> From: Minchan Kim [mailto:minchan@xxxxxxxxxx] >> >> Okay. Now it works but zcache coupled with zsmalloc tightly. >> User of zsmalloc should never know internal of zs_handle. >> >> 3) >> >> - zsmalloc.h >> void *zs_handle_to_ptr(struct zs_handle handle) >> { >> return handle.hanle; >> } >> >> static struct zv_hdr *zv_create(..) >> { >> struct zs_handle handle; >> .. >> handle = zs_malloc(pool, size); >> .. >> return zs_handle_to_ptr(handle); >> } >> >> Why should zsmalloc support such interface? >> It's a zcache problem so it's desriable to solve it in zcache internal. >> And in future, if we can add/remove zs_handle's fields, we can't make >> sure such API. > > Hi Minchan -- > > I'm confused so maybe I am misunderstanding or you can > explain further. It seems like you are trying to redesign > zsmalloc so that it can be a pure abstraction in a library. > While I understand and value abstractions in software > designs, the primary use now of zsmalloc is in zcache. If > there are other users that require a different interface > or a more precise abstract API, zsmalloc could then > evolve to meet the needs of multiple users. But I think At least, zram is also primary user and it also has such mess although it's not severe than zcache. zram->table[index].handle sometime has real (void*) handle, sometime (struct page*). And I assume ramster you sent yesterday will be. I think there are already many mess and I bet it will prevent going to mainline. Especially, handle problem is severe because it a arguement of most functions exported in zsmalloc So, we should clean up before late, IMHO. > zcache is going to need more access to the internals > of its allocator, not less. Zsmalloc is currently missing > some important functionality that (I believe) will be > necessary to turn zcache into an enterprise-ready, If you have such TODO list, could you post it? It helps direction point of my stuff. > always-on kernel feature. If it evolves to add that > functionality, then it may no longer be able to provide > generic abstract access... in which case generic zsmalloc > may then have zero users in the kernel. Hmm, Do you want to make zsmalloc by zcache owned private allocator? > > So I'd suggest we hold off on trying to make zsmalloc > "pretty" until we better understand how it will be used > by zcache (and ramster) and, if there are any, any future > users. zcache isn't urgent? I'm okay about zcache but at least, zram is when it merged into mainline, I think. Many embedded system have a advantage with it so I hope we finish zsmalloc mess as soon as possble. > > That's just my opinion... Dan, Thanks for sharing your opinion. > Dan > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majordomo@xxxxxxxxx. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ > Don't email: <a href=ilto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a> > -- Kind regards, Minchan Kim -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>