On Mon, Apr 19, 2021 at 10:50:43PM +0000, Dennis Zhou wrote: > Hello, > > This series is a continuation of Roman's series in [1]. It aims to solve > chunks holding onto free pages by adding a reclaim process to the percpu > balance work item. > > The main difference is that the nr_empty_pop_pages is now managed at > time of isolation instead of intermixed. This helps with deciding which > chunks to free instead of having to interleave returning chunks to > active duty. > > The allocation priority is as follows: > 1) appropriate chunk slot increasing until fit > 2) sidelined chunks > 3) full free chunks > > The last slot for to_depopulate is never used for allocations. > > A big thanks to Roman for initiating the work and being available for > iterating on these ideas. > > This patchset contains the following 4 patches: > 0001-percpu-factor-out-pcpu_check_block_hint.patch > 0002-percpu-use-pcpu_free_slot-instead-of-pcpu_nr_slots-1.patch > 0003-percpu-implement-partial-chunk-depopulation.patch > 0004-percpu-use-reclaim-threshold-instead-of-running-for-.patch > > 0001 and 0002 are clean ups. 0003 implement partial chunk depopulation > initially from Roman. 0004 adds a reclaim threshold so we do not need to > schedule for every page freed. > > This series is on top of percpu$for-5.14 67c2669d69fb. > > diffstats below: > > Dennis Zhou (2): > percpu: use pcpu_free_slot instead of pcpu_nr_slots - 1 > percpu: use reclaim threshold instead of running for every page > > Roman Gushchin (2): > percpu: factor out pcpu_check_block_hint() > percpu: implement partial chunk depopulation > > mm/percpu-internal.h | 5 + > mm/percpu-km.c | 5 + > mm/percpu-stats.c | 20 ++-- > mm/percpu-vm.c | 30 ++++++ > mm/percpu.c | 252 ++++++++++++++++++++++++++++++++++++++----- > 5 files changed, 278 insertions(+), 34 deletions(-) > > Thanks, > Dennis I've applied this to for-5.14 with 1 modification to the batching threshold, 4 pages is quite little, so make it 16. Thanks, Dennis
