Re: [PATCH -V3 2/8] memcg: Add HugeTLB extension
From: Andrew Morton <hidden>
Date: 2012-03-14 23:43:42
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On Wed, 14 Mar 2012 15:51:50 +0530 "Aneesh Kumar K.V" [off-list ref] wrote:
On Tue, 13 Mar 2012 14:33:16 -0700, Andrew Morton [off-list ref] wrote:quoted
On Tue, 13 Mar 2012 12:37:06 +0530 "Aneesh Kumar K.V" [off-list ref] wrote:quoted
+static int mem_cgroup_hugetlb_usage(struct mem_cgroup *memcg) +{ + int idx; + for (idx = 0; idx < hugetlb_max_hstate; idx++) { + if (memcg->hugepage[idx].usage > 0) + return memcg->hugepage[idx].usage; + } + return 0; +}Please document the function? Had you done this, I might have been able to work out why the function bales out on the first used hugepage size, but I can't :(I guess the function is named wrongly. I will rename it to mem_cgroup_have_hugetlb_usage() in the next iteration ? The function will return (bool) 1 if it has any hugetlb resource usage.quoted
This could have used for_each_hstate(), had that macro been better designed (or updated).Can you explain this ?. for_each_hstate allows to iterate over different hstates. But here we need to look at different hugepage rescounter in memcg. I can still use for_each_hstate() and find the hstate index (h - hstates) and use that to index memcg rescounter array. But that would make it more complex ?
If the for_each_hstate() macro took an additional arg which holds the base address of the array, that macro could have been used here. Or perhaps not - I didn't look too closely ;) It isn't important.