On Mon, Feb 12, 2024 at 9:35 AM Zi Yan <zi.yan@xxxxxxxx> wrote: > > From: Zi Yan <ziy@xxxxxxxxxx> > > Hi all, > > This patchset enables >0 order folio memory compaction, which is one of > the prerequisitions for large folio support[1]. It is on top of > mm-everything-2024-02-10-00-56. > > I am aware of that split free pages is necessary for folio > migration in compaction, since if >0 order free pages are never split > and no order-0 free page is scanned, compaction will end prematurely due > to migration returns -ENOMEM. Free page split becomes a must instead of > an optimization. > > lkp ncompare results (on a 8-CPU (Intel Xeon E5-2650 v4 @2.20GHz) 16G VM) > for default LRU (-no-mglru) and CONFIG_LRU_GEN are shown at the bottom, > copied from V3[4], since V4 is only a code refactoring of V3. > In sum, most of vm-scalability applications do not see performance > change, and the others see ~4% to ~26% performance boost under default LRU > and ~2% to ~6% performance boost under CONFIG_LRU_GEN. Suren has been testing 64KB THP on Android and seeing regressions under memory pressure (a significant portion of client devices are always under memory pressure). Hopefully this series will help. I threw this series into some stress tests we have with both 64KB and 2MB THP enabled and didn't see any obvious problems. Tested-by: Yu Zhao <yuzhao@xxxxxxxxxx> > Overview > === > > To support >0 order folio compaction, the patchset changes how free pages used > for migration are kept during compaction. Free pages used to be split into > order-0 pages that are post allocation processed (i.e., PageBuddy flag cleared, > page order stored in page->private is zeroed, and page reference is set to 1). > Now all free pages are kept in a MAX_ORDER+1 array of page lists based > on their order without post allocation process. When migrate_pages() asks for > a new page, one of the free pages, based on the requested page order, is > then processed and given out. And THP <2MB would need this feature (spell it out). > vm-scalability results on CONFIG_LRU_GEN > === > > ========================================================================================= > compiler/kconfig/rootfs/runtime/tbox_group/test/testcase: > gcc-13/defconfig/debian/300s/qemu-vm/mmap-xread-seq-mt/vm-scalability > > commit: > 6.8.0-rc1-mm-everything-2024-01-29-07-19+ > 6.8.0-rc1-split-folio-in-compaction+ > 6.8.0-rc1-folio-migration-in-compaction+ > 6.8.0-rc1-folio-migration-free-page-split+ > > 6.8.0-rc1-mm-eve 6.8.0-rc1-split-folio-in-co 6.8.0-rc1-folio-migration-i 6.8.0-rc1-folio-migration-f > ---------------- --------------------------- --------------------------- --------------------------- > %stddev %change %stddev %change %stddev %change %stddev > \ | \ | \ | \ > 15107616 +3.2% 15590339 +1.3% 15297619 +3.0% 15567998 vm-scalability.throughput > > ========================================================================================= > compiler/kconfig/rootfs/runtime/tbox_group/test/testcase: > gcc-13/defconfig/debian/300s/qemu-vm/mmap-pread-seq/vm-scalability > > commit: > 6.8.0-rc1-mm-everything-2024-01-29-07-19+ > 6.8.0-rc1-split-folio-in-compaction+ > 6.8.0-rc1-folio-migration-in-compaction+ > 6.8.0-rc1-folio-migration-free-page-split+ > > 6.8.0-rc1-mm-eve 6.8.0-rc1-split-folio-in-co 6.8.0-rc1-folio-migration-i 6.8.0-rc1-folio-migration-f > ---------------- --------------------------- --------------------------- --------------------------- > %stddev %change %stddev %change %stddev %change %stddev > \ | \ | \ | \ > 12611785 +1.8% 12832919 +0.9% 12724223 +1.6% 12812682 vm-scalability.throughput > > > ========================================================================================= > compiler/kconfig/rootfs/runtime/tbox_group/test/testcase: > gcc-13/defconfig/debian/300s/qemu-vm/lru-file-readtwice/vm-scalability > > commit: > 6.8.0-rc1-mm-everything-2024-01-29-07-19+ > 6.8.0-rc1-split-folio-in-compaction+ > 6.8.0-rc1-folio-migration-in-compaction+ > 6.8.0-rc1-folio-migration-free-page-split+ > > 6.8.0-rc1-mm-eve 6.8.0-rc1-split-folio-in-co 6.8.0-rc1-folio-migration-i 6.8.0-rc1-folio-migration-f > ---------------- --------------------------- --------------------------- --------------------------- > %stddev %change %stddev %change %stddev %change %stddev > \ | \ | \ | \ > 9833393 +5.7% 10390190 +3.0% 10126606 +5.9% 10408804 vm-scalability.throughput > > ========================================================================================= > compiler/kconfig/rootfs/runtime/tbox_group/test/testcase: > gcc-13/defconfig/debian/300s/qemu-vm/lru-file-mmap-read/vm-scalability > > commit: > 6.8.0-rc1-mm-everything-2024-01-29-07-19+ > 6.8.0-rc1-split-folio-in-compaction+ > 6.8.0-rc1-folio-migration-in-compaction+ > 6.8.0-rc1-folio-migration-free-page-split+ > > 6.8.0-rc1-mm-eve 6.8.0-rc1-split-folio-in-co 6.8.0-rc1-folio-migration-i 6.8.0-rc1-folio-migration-f > ---------------- --------------------------- --------------------------- --------------------------- > %stddev %change %stddev %change %stddev %change %stddev > \ | \ | \ | \ > 7034709 ± 3% +2.9% 7241429 +3.2% 7256680 ± 2% +3.9% 7308375 vm-scalability.throughput > > > > vm-scalability results on default LRU (with -no-mglru suffix) > === > > ========================================================================================= > compiler/kconfig/rootfs/runtime/tbox_group/test/testcase: > gcc-13/defconfig/debian/300s/qemu-vm/mmap-xread-seq-mt/vm-scalability > > commit: > 6.8.0-rc1-mm-everything-2024-01-29-07-19-no-mglru+ > 6.8.0-rc1-split-folio-in-compaction-no-mglru+ > 6.8.0-rc1-folio-migration-in-compaction-no-mglru+ > 6.8.0-rc1-folio-migration-free-page-split-no-mglru+ > > 6.8.0-rc1-mm-eve 6.8.0-rc1-split-folio-in-co 6.8.0-rc1-folio-migration-i 6.8.0-rc1-folio-migration-f > ---------------- --------------------------- --------------------------- --------------------------- > %stddev %change %stddev %change %stddev %change %stddev > \ | \ | \ | \ > 14401491 +3.7% 14940270 +2.4% 14748626 +4.0% 14975716 vm-scalability.throughput > > ========================================================================================= > compiler/kconfig/rootfs/runtime/tbox_group/test/testcase: > gcc-13/defconfig/debian/300s/qemu-vm/mmap-pread-seq/vm-scalability > > commit: > 6.8.0-rc1-mm-everything-2024-01-29-07-19-no-mglru+ > 6.8.0-rc1-split-folio-in-compaction-no-mglru+ > 6.8.0-rc1-folio-migration-in-compaction-no-mglru+ > 6.8.0-rc1-folio-migration-free-page-split-no-mglru+ > > 6.8.0-rc1-mm-eve 6.8.0-rc1-split-folio-in-co 6.8.0-rc1-folio-migration-i 6.8.0-rc1-folio-migration-f > ---------------- --------------------------- --------------------------- --------------------------- > %stddev %change %stddev %change %stddev %change %stddev > \ | \ | \ | \ > 11407497 +5.1% 11989632 -0.5% 11349272 +4.8% 11957423 vm-scalability.throughput > > ========================================================================================= > compiler/kconfig/rootfs/runtime/tbox_group/test/testcase: > gcc-13/defconfig/debian/300s/qemu-vm/mmap-pread-seq-mt/vm-scalability > > commit: > 6.8.0-rc1-mm-everything-2024-01-29-07-19-no-mglru+ > 6.8.0-rc1-split-folio-in-compaction-no-mglru+ > 6.8.0-rc1-folio-migration-in-compaction-no-mglru+ > 6.8.0-rc1-folio-migration-free-page-split-no-mglru+ > > 6.8.0-rc1-mm-eve 6.8.0-rc1-split-folio-in-co 6.8.0-rc1-folio-migration-i 6.8.0-rc1-folio-migration-f > ---------------- --------------------------- --------------------------- --------------------------- > %stddev %change %stddev %change %stddev %change %stddev > \ | \ | \ | \ > 11348474 +3.3% 11719453 -1.2% 11208759 +3.7% 11771926 vm-scalability.throughput > > ========================================================================================= > compiler/kconfig/rootfs/runtime/tbox_group/test/testcase: > gcc-13/defconfig/debian/300s/qemu-vm/lru-file-readtwice/vm-scalability > > commit: > 6.8.0-rc1-mm-everything-2024-01-29-07-19-no-mglru+ > 6.8.0-rc1-split-folio-in-compaction-no-mglru+ > 6.8.0-rc1-folio-migration-in-compaction-no-mglru+ > 6.8.0-rc1-folio-migration-free-page-split-no-mglru+ > > 6.8.0-rc1-mm-eve 6.8.0-rc1-split-folio-in-co 6.8.0-rc1-folio-migration-i 6.8.0-rc1-folio-migration-f > ---------------- --------------------------- --------------------------- --------------------------- > %stddev %change %stddev %change %stddev %change %stddev > \ | \ | \ | \ > 8065614 ± 3% +7.7% 8686626 ± 2% +5.0% 8467577 ± 4% +11.8% 9016077 ± 2% vm-scalability.throughput > > ========================================================================================= > compiler/kconfig/rootfs/runtime/tbox_group/test/testcase: > gcc-13/defconfig/debian/300s/qemu-vm/lru-file-mmap-read/vm-scalability > > commit: > 6.8.0-rc1-mm-everything-2024-01-29-07-19-no-mglru+ > 6.8.0-rc1-split-folio-in-compaction-no-mglru+ > 6.8.0-rc1-folio-migration-in-compaction-no-mglru+ > 6.8.0-rc1-folio-migration-free-page-split-no-mglru+ > > 6.8.0-rc1-mm-eve 6.8.0-rc1-split-folio-in-co 6.8.0-rc1-folio-migration-i 6.8.0-rc1-folio-migration-f > ---------------- --------------------------- --------------------------- --------------------------- > %stddev %change %stddev %change %stddev %change %stddev > \ | \ | \ | \ > 6438422 ± 2% +27.5% 8206734 ± 2% +10.6% 7118390 +26.2% 8127192 ± 4% vm-scalability.throughput Thanks for the data! Based on the above: Test case default MGLRU Change ============================================================= mmap-xread-seq-mt/vm-scalability 14975716 15567998 +4% mmap-pread-seq/vm-scalability 11957423 12812682 +7% mmap-pread-seq-mt/vm-scalability 11771926 unavail N/A lru-file-readtwice/vm-scalability 9016077 10408804 +15% lru-file-mmap-read/vm-scalability 8127192 7308375 -10% So it seems that MGLRU regressed for the last test. I'll find someone on our team to take a look.
