"JP Kobryn (Meta)" <[email protected]> writes: > On 3/15/26 7:54 PM, Huang, Ying wrote: >> "JP Kobryn (Meta)" <[email protected]> writes: >> >>> On 3/13/26 12:34 AM, Vlastimil Babka (SUSE) wrote: >>>> On 3/13/26 07:14, JP Kobryn (Meta) wrote: >>>>> On 3/12/26 10:07 PM, Huang, Ying wrote: >>>>>> "JP Kobryn (Meta)" <[email protected]> writes: >>>>>> >>>>>>> On 3/12/26 6:40 AM, Vlastimil Babka (SUSE) wrote: >>>>>>> >>>>>>> How about I change from per-policy hit/miss/foreign triplets to a single >>>>>>> aggregated policy triplet (i.e. just 3 new counters which account for >>>>>>> all policies)? They would follow the same hit/miss/foreign semantics >>>>>>> already proposed (visible in quoted text above). This would still >>>>>>> provide the otherwise missing signal of whether policy-driven >>>>>>> allocations to a node are intentional or fallback. >>>>>>> >>>>>>> Note that I am also planning on moving the stats off of the memcg so the >>>>>>> 3 new counters will be global per-node in response to similar feedback. >>>>>> >>>>>> Emm, what's the difference between these newly added counters and the >>>>>> existing numa_hit/miss/foreign counters? >>>>> >>>>> The existing counters don't account for node masks in the policies that >>>>> make use of them. An allocation can land on a node in the mask and still >>>>> be considered a miss because it wasn't the preferred node. >>>> That sounds like we could just a new counter e.g. numa_hit_preferred >>>> and >>>> adjust definitions accordingly? Or some other variant that fills the gap? >>> >>> It's an interesting thought. Looking into these existing counters more, >>> the in-kernel direct node allocations, which don't fall under any >>> mempolicy, are also included in these stats. One good example might be >>> include/linux/skbuff.h, where __dev_alloc_pages() calls >>> alloc_pages_node_noprof(NUMA_NO_NODE, ...) which eventually reaches >>> zone_statistics() and increments the stats. >> IIUC, the default memory policy is used here, that is, MPOL_LOCAL. > > I'm not seeing that. zone_statistics() is eventually reached. > alloc_pages_mpol() is not.
Yes. The page isn't allocated through alloc_pages_mpol(). For example, if we want to allocate pages for the kernel instead of user space applications. However, IMHO, the equivalent memory policy is MPOL_LOCAL, that is, allocate from local node firstly, then fallback to other nodes. I don't think that alloc_pages_mpol() is so special. --- Best Regards, Huang, Ying
