On 04/09/2019 01:01, Mark Johnston wrote: > Some of the vm_lowmem eventhandlers probably shouldn't be called each > time the page daemon scans the inactive queue (every 0.1s under memory > pressure). ufsdirhash_lowmem and mb_reclaim in particular don't seem > like they need to be invoked very frequently. We could easily define > multiple eventhandlers to differentiate between these cases, though.
My proposal is to run uma_reclaim(UMA_RECLAIM_TRIM) before invoking vm_lowmem. If that reclaims "enough" memory, then do not call vm_lowmem at all. Oh, and I have a related question. Say, a zone has X items in use and Y items in cache. After running vm_lowmem the composition changes to X - C and Y + C respectively. Then we run uma_reclaim(UMA_RECLAIM_TRIM). Question: is that guaranteed to free at least C items? I am thinking about a possibility that the zone's workset size is estimated to be at least X (and maybe even more than X + Y). In that case UMA_RECLAIM_TRIM won't free those C items, they will stay in the cache. So, it seems like releasing them was in vain, at least for the immediate reclaim. -- Andriy Gapon _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
