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charset="UTF-8" X-Rspamd-Queue-Id: 9901140002 X-Rspamd-Server: rspam09 X-Rspam-User: X-Stat-Signature: qk66ik184acaah849jkdeqkjhtb5ot1r X-HE-Tag: 1676969352-11553 X-HE-Meta: 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 R6xcXj1L HUHtdX+JoxKrWzvsDFoCduJmPYWRa3ljkuAJGWbcalj7EqCO09IP7Qvtyh8uNqbWW3rhfbFgo4nTTTO5QTcOwuq448R6KxcOE0f43BJNDJ1ZAhlsDnOHXKLUUrHLI2Ix/hOjqjpggPgE53ddCX5CqokJoAd9ZPHEAmGoTr1JA7Bw7uILv5z66ZJ6E7SDPjceN3Y7jLQbVH69S+oS6QmxrvgSI5e4DLZmyM1uUEX0TfgZqMlIIkpddOLC9thVCcbrCv/DqRUVholI/Symv9GOgUePLH6cplEYvbXFvT45Qklq6kcVBJae1tHHL9bneQbXTiBcgpI494AMjrU37aQNfPpaPNVc/XcxCNJbPWC8zBXOW92l3x3gP60bMCVCNOqy6RDNWukZkeBVR9ZP8gaJOGfx1gy6eeIBNrqH0zNSIQ4+mC0M= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000001, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Sun, Feb 19, 2023 at 4:05 AM Matthew Wilcox wrote: > > On Sat, Feb 18, 2023 at 11:33:16PM -0800, Nhat Pham wrote: > > +++ b/mm/workingset.c > > @@ -244,6 +244,30 @@ static void *lru_gen_eviction(struct folio *folio) > > return pack_shadow(mem_cgroup_id(memcg), pgdat, token, refs); > > } > > > > +/* > > + * Test if the folio is recently evicted. > > + * > > + * As a side effect, also populates the references with > > + * values unpacked from the shadow of the evicted folio. > > + */ > > I find this comment hard to understand. First it talks about "the > folio", but it doesn't pass a folio. Then it talks about "the > references", but I don't have any idea what those are either. > > I think what you mean is, > > * Test if the shadow entry is for a folio which was recently evicted. > * Fills in @memcgid, @pgdat, @token and @workingset with values > * extracted from the shadow entry. I'll fix this comment in the next version. Thanks for the suggestion! > > > +static bool lru_gen_test_recent(void *shadow, bool file, int *memcgid, > > + struct pglist_data **pgdat, unsigned long *token, bool *workingset) > > +{ > > + struct mem_cgroup *eviction_memcg; > > + struct lruvec *lruvec; > > + struct lru_gen_struct *lrugen; > > + unsigned long min_seq; > > + > > + unpack_shadow(shadow, memcgid, pgdat, token, workingset); > > + eviction_memcg = mem_cgroup_from_id(*memcgid); > > + > > + lruvec = mem_cgroup_lruvec(eviction_memcg, *pgdat); > > + lrugen = &lruvec->lrugen; > > + > > + min_seq = READ_ONCE(lrugen->min_seq[file]); > > + return (*token >> LRU_REFS_WIDTH) == (min_seq & (EVICTION_MASK >> LRU_REFS_WIDTH)); > > +} > > [...] > > > +/* > > + * Test if the folio is recently evicted by checking if > > + * refault distance of shadow exceeds workingset size. > > * > > - * Calculates and evaluates the refault distance of the previously > > - * evicted folio in the context of the node and the memcg whose memory > > - * pressure caused the eviction. > > + * As a side effect, populate workingset with the value > > + * unpacked from shadow. > > */ > > 1. Shouldn't this be kernel-doc? Hmm good point... > 2. Again, don't use the term "side effect" here. It's just one of > the things that the function _does_. > I'll fix this! Thanks for pointing it out.