On Friday 10 January 2014 07:53 PM, Andrew Morton wrote: > On Thu, 5 Dec 2013 12:13:16 -0500 Santosh Shilimkar > <santosh.shilim...@ti.com> wrote: > >> On Thursday 05 December 2013 11:59 AM, Tejun Heo wrote: >>> Hello, >>> >>> On Thu, Dec 05, 2013 at 03:12:30PM +0200, Grygorii Strashko wrote: >>>> I'll try to provide more technical details here. >>>> As Santosh mentioned in previous e-mails, it's not easy to simply >>>> get rid of using MAX_NUMNODES: >>>> 1) we introduce new interface memblock_allocX >>>> 2) our interface uses memblock APIs __next_free_mem_range_rev() >>>> and __next_free_mem_range() >>>> 3) __next_free_mem_range_rev() and __next_free_mem_range() use MAX_NUMNODES >>>> 4) _next_free_mem_range_rev() and __next_free_mem_range() are used >>>> standalone, >>>> outside of our interface as part of *for_each_free_mem_range* or >>>> for_each_mem_pfn_range .. >>>> >>>> The point [4] leads to necessity to find and correct all places where >>>> memmblock APIs >>>> are used and where it's expected to get MAX_NUMNODES as input parameter. >>>> The major problem is that simple "grep" will not work, because memmblock >>>> APIs calls >>>> are hidden inside other MM modules and it's not always clear >>>> what will be passed as input parameters to APIs of these MM modules >>>> (for example sparse_memory_present_with_active_regions() or sparse.c). >>> >>> Isn't that kinda trivial to work around? Make those functions accept >>> both MAX_NUMNODES and NUMA_NO_NODE but emit warning on MAX_NUMNODES >>> (preferably throttled reasonably). Given the history of API, we'd >>> probably want to keep such warning for extended period of time but >>> that's what we'd need to do no matter what. >>> >> Looks a good idea. >> >>>> As result, WIP patch, I did, and which was posted by Santosh illustrates >>>> the probable size and complexity of the change. >>> >>> Again, I don't really mind the order things happen but I don't think >>> it's a good idea to spread misusage with a new API. You gotta deal >>> with it one way or the other. >>> >>>> Sorry, but question here is not "Do or not to do?", but rather 'how to >>>> do?", >>>> taking into account complexity and state of the current MM code. >>>> For example. would it be ok if I'll workaround the issue as in the >>>> attached patch? >>> >>> Well, it's more of when. It's not really a technically difficult >>> task and all I'm saying is it better be sooner than later. >>> >> Fair enough. Based on your suggestion, we will try to see if >> we can proceed with 4) accepting both MAX_NUMNODES and NUMA_NO_NODE. >> >> Thanks for the suggestion. > > So where do we now stand with this MAX_NUMNODES-vs-NUMA_NO_NODE mess? > Is the conversion to NUMA_NO_NODE in current linux-next completed and > nicely tested? > >From all the report so far, there were actually only 3 places in x86 code using MAX_NUMNODES and fix for that is already in your queue. So I guess we are good on that aspect now.
Regards, Santosh -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
