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Add all those folios to a list. >>> >>> Signed-off-by: Raghavendra K T >>> --- >> >> Hi, just taking a quick look... > > Hello Harry, > Thanks for taking a look at the patches. >> >>>   mm/kscand.c | 319 +++++++++++++++++++++++++++++++++++++++++++++++++++- >>>   1 file changed, 318 insertions(+), 1 deletion(-) >>> >>> diff --git a/mm/kscand.c b/mm/kscand.c >>> index d5b0d3041b0f..0edec1b7730d 100644 >>> --- a/mm/kscand.c >>> +++ b/mm/kscand.c >>> @@ -42,6 +55,8 @@ static struct kmem_cache *kscand_slot_cache >>> __read_mostly; >>> @@ -84,11 +122,275 @@ static void kscand_wait_work(void) >>>               scan_sleep_jiffies); >>>   } >>> +static inline bool is_valid_folio(struct folio *folio) >>> +{ >>> +    if (!folio || folio_test_unevictable(folio) || ! >>> folio_mapped(folio) || >>> +        folio_is_zone_device(folio) || >>> folio_maybe_mapped_shared(folio)) >>> +        return false; >>> + >>> +    return true; >>> +} >> >> What makes it undesirable to migrate shared folios? > > This was mostly to avoid shared libraries, but yes this also > should have accompanied with EXEC flag to refine further. > This also avoids moving around shared data. I will experiment more > and add additional filters OR remove the check. > Atleast experiment with microbenchmark gives a positive benefit if I remove check for folio_maybe_mapped_shared() folios. Will respin accordingly. (also after checking some real workloads). - Raghu