Re: [PATCH v3 00/11] Mitigate a vmap lock contention v3

Uladzislau Rezki
2024-02-29T10:38:08Z

>
> I finally finished the testing w/o and with your above improvement
> patch. Testing is done on a system with 128 cpus. The system with 288
> cpus is not available because of some console connection. Attach the log
> here. In some testing after rebooting, I found it could take more than 30
> minutes, I am not sure if it's caused by my messy code change. I finally
> cleaned up all of them and take a clean linux-next to test, then apply
> your above draft code.

> [root@dell-per6515-03 linux]# nproc
> 128
> [root@dell-per6515-03 linux]# free -h
> total used free shared buff/cache available
> Mem: 124Gi 2.6Gi 122Gi 21Mi 402Mi 122Gi
> Swap: 4.0Gi 0B 4.0Gi
>
> 1)linux-next kernel w/o improving code from Uladzislau
> -------------------------------------------------------
> [root@dell-per6515-03 linux]# time tools/testing/selftests/mm/test_vmalloc.sh run_test_mask=127 nr_threads=64
> Run the test with following parameters: run_test_mask=127 nr_threads=64
> Done.
> Check the kernel ring buffer to see the summary.
>
> real 4m28.018s
> user 0m0.015s
> sys 0m4.712s
> [root@dell-per6515-03 ~]# sort -h /proc/allocinfo | tail -10
> 21405696 5226 mm/memory.c:1122 func:folio_prealloc
> 26199936 7980 kernel/fork.c:309 func:alloc_thread_stack_node
> 29822976 7281 mm/readahead.c:247 func:page_cache_ra_unbounded
> 99090432 96768 drivers/iommu/iova.c:604 func:iova_magazine_alloc
> 107638784 6320 mm/readahead.c:468 func:ra_alloc_folio
> 120560528 29439 mm/mm_init.c:2521 func:alloc_large_system_hash
> 134742016 32896 mm/percpu-vm.c:95 func:pcpu_alloc_pages
> 263192576 64256 mm/page_ext.c:270 func:alloc_page_ext
> 266797056 65136 include/linux/mm.h:2848 func:pagetable_alloc
> 507617280 32796 mm/slub.c:2305 func:alloc_slab_page
> [root@dell-per6515-03 ~]#
> [root@dell-per6515-03 ~]#
> [root@dell-per6515-03 linux]# time tools/testing/selftests/mm/test_vmalloc.sh run_test_mask=127 nr_threads=128
> Run the test with following parameters: run_test_mask=127 nr_threads=128
> Done.
> Check the kernel ring buffer to see the summary.
>
> real 6m19.328s
> user 0m0.005s
> sys 0m9.476s
> [root@dell-per6515-03 ~]# sort -h /proc/allocinfo | tail -10
> 21405696 5226 mm/memory.c:1122 func:folio_prealloc
> 26889408 8190 kernel/fork.c:309 func:alloc_thread_stack_node
> 29822976 7281 mm/readahead.c:247 func:page_cache_ra_unbounded
> 99090432 96768 drivers/iommu/iova.c:604 func:iova_magazine_alloc
> 107638784 6320 mm/readahead.c:468 func:ra_alloc_folio
> 120560528 29439 mm/mm_init.c:2521 func:alloc_large_system_hash
> 134742016 32896 mm/percpu-vm.c:95 func:pcpu_alloc_pages
> 263192576 64256 mm/page_ext.c:270 func:alloc_page_ext
> 550068224 34086 mm/slub.c:2305 func:alloc_slab_page
> 664535040 162240 include/linux/mm.h:2848 func:pagetable_alloc
> [root@dell-per6515-03 ~]#
> [root@dell-per6515-03 ~]#
> [root@dell-per6515-03 linux]# time tools/testing/selftests/mm/test_vmalloc.sh run_test_mask=127 nr_threads=256
> Run the test with following parameters: run_test_mask=127 nr_threads=256
> Done.
> Check the kernel ring buffer to see the summary.
>
> real 19m10.657s
> user 0m0.015s
> sys 0m20.959s
> [root@dell-per6515-03 ~]# sort -h /proc/allocinfo | tail -10
> 22441984 5479 mm/shmem.c:1634 func:shmem_alloc_folio
> 26758080 8150 kernel/fork.c:309 func:alloc_thread_stack_node
> 35880960 8760 mm/readahead.c:247 func:page_cache_ra_unbounded
> 99090432 96768 drivers/iommu/iova.c:604 func:iova_magazine_alloc
> 120560528 29439 mm/mm_init.c:2521 func:alloc_large_system_hash
> 122355712 7852 mm/readahead.c:468 func:ra_alloc_folio
> 134742016 32896 mm/percpu-vm.c:95 func:pcpu_alloc_pages
> 263192576 64256 mm/page_ext.c:270 func:alloc_page_ext
> 708231168 50309 mm/slub.c:2305 func:alloc_slab_page
> 1107296256 270336 include/linux/mm.h:2848 func:pagetable_alloc
> [root@dell-per6515-03 ~]#
>
> 2)linux-next kernel with improving code from Uladzislau
> -----------------------------------------------------
> [root@dell-per6515-03 linux]# time tools/testing/selftests/mm/test_vmalloc.sh run_test_mask=127 nr_threads=64
> Run the test with following parameters: run_test_mask=127 nr_threads=64
> Done.
> Check the kernel ring buffer to see the summary.
>
> real 4m27.226s
> user 0m0.006s
> sys 0m4.709s
> [root@dell-per6515-03 linux]# sort -h /proc/allocinfo | tail -10
> 38023168 9283 mm/readahead.c:247 func:page_cache_ra_unbounded
> 72228864 17634 fs/xfs/xfs_buf.c:390 [xfs] func:xfs_buf_alloc_pages
> 99090432 96768 drivers/iommu/iova.c:604 func:iova_magazine_alloc
> 99863552 97523 fs/xfs/xfs_icache.c:81 [xfs] func:xfs_inode_alloc
> 120560528 29439 mm/mm_init.c:2521 func:alloc_large_system_hash
> 136314880 33280 mm/percpu-vm.c:95 func:pcpu_alloc_pages
> 184176640 10684 mm/readahead.c:468 func:ra_alloc_folio
> 263192576 64256 mm/page_ext.c:270 func:alloc_page_ext
> 284700672 69507 include/linux/mm.h:2848 func:pagetable_alloc
> 601427968 36377 mm/slub.c:2305 func:alloc_slab_page
> [root@dell-per6515-03 linux]# time tools/testing/selftests/mm/test_vmalloc.sh run_test_mask=127 nr_threads=128
> Run the test with following parameters: run_test_mask=127 nr_threads=128
> Done.
> Check the kernel ring buffer to see the summary.
>
> real 6m16.960s
> user 0m0.007s
> sys 0m9.465s
> [root@dell-per6515-03 linux]# sort -h /proc/allocinfo | tail -10
> 38158336 9316 mm/readahead.c:247 func:page_cache_ra_unbounded
> 72220672 17632 fs/xfs/xfs_buf.c:390 [xfs] func:xfs_buf_alloc_pages
> 99090432 96768 drivers/iommu/iova.c:604 func:iova_magazine_alloc
> 99863552 97523 fs/xfs/xfs_icache.c:81 [xfs] func:xfs_inode_alloc
> 120560528 29439 mm/mm_init.c:2521 func:alloc_large_system_hash
> 136314880 33280 mm/percpu-vm.c:95 func:pcpu_alloc_pages
> 184504320 10710 mm/readahead.c:468 func:ra_alloc_folio
> 263192576 64256 mm/page_ext.c:270 func:alloc_page_ext
> 427884544 104464 include/linux/mm.h:2848 func:pagetable_alloc
> 697311232 45159 mm/slub.c:2305 func:alloc_slab_page
> [root@dell-per6515-03 linux]# time tools/testing/selftests/mm/test_vmalloc.sh run_test_mask=127 nr_threads=256
> Run the test with following parameters: run_test_mask=127 nr_threads=256
> Done.
> Check the kernel ring buffer to see the summary.
>
> real 21m15.673s
> user 0m0.008s
> sys 0m20.259s
> [root@dell-per6515-03 linux]# sort -h /proc/allocinfo | tail -10
> 38158336 9316 mm/readahead.c:247 func:page_cache_ra_unbounded
> 72224768 17633 fs/xfs/xfs_buf.c:390 [xfs] func:xfs_buf_alloc_pages
> 99090432 96768 drivers/iommu/iova.c:604 func:iova_magazine_alloc
> 99863552 97523 fs/xfs/xfs_icache.c:81 [xfs] func:xfs_inode_alloc
> 120560528 29439 mm/mm_init.c:2521 func:alloc_large_system_hash
> 136314880 33280 mm/percpu-vm.c:95 func:pcpu_alloc_pages
> 184504320 10710 mm/readahead.c:468 func:ra_alloc_folio
> 263192576 64256 mm/page_ext.c:270 func:alloc_page_ext
> 506974208 123773 include/linux/mm.h:2848 func:pagetable_alloc
> 809504768 53621 mm/slub.c:2305 func:alloc_slab_page
> [root@dell-per6515-03 linux]# time tools/testing/selftests/mm/test_vmalloc.sh run_test_mask=127 nr_threads=256
> Run the test with following parameters: run_test_mask=127 nr_threads=256
> Done.
> Check the kernel ring buffer to see the summary.
>
> real 21m36.580s
> user 0m0.012s
> sys 0m19.912s
> [root@dell-per6515-03 linux]# sort -h /proc/allocinfo | tail -10
> 38977536 9516 mm/readahead.c:247 func:page_cache_ra_unbounded
> 72273920 17645 fs/xfs/xfs_buf.c:390 [xfs] func:xfs_buf_alloc_pages
> 99090432 96768 drivers/iommu/iova.c:604 func:iova_magazine_alloc
> 99895296 97554 fs/xfs/xfs_icache.c:81 [xfs] func:xfs_inode_alloc
> 120560528 29439 mm/mm_init.c:2521 func:alloc_large_system_hash
> 141033472 34432 mm/percpu-vm.c:95 func:pcpu_alloc_pages
> 186064896 10841 mm/readahead.c:468 func:ra_alloc_folio
> 263192576 64256 mm/page_ext.c:270 func:alloc_page_ext
> 541237248 132138 include/linux/mm.h:2848 func:pagetable_alloc
> 694718464 41216 mm/slub.c:2305 func:alloc_slab_page
>
>
Thank you for testing this. So ~132mb with a patch. I think it looks
good but i might change the draft version and send out a new version.

Thank you again!

--
Uladzislau Rezki