linux_dsm_epyc7002/mm
NeilBrown 8d92890bd6 mm/writeback: discard NR_UNSTABLE_NFS, use NR_WRITEBACK instead
After an NFS page has been written it is considered "unstable" until a
COMMIT request succeeds.  If the COMMIT fails, the page will be
re-written.

These "unstable" pages are currently accounted as "reclaimable", either
in WB_RECLAIMABLE, or in NR_UNSTABLE_NFS which is included in a
'reclaimable' count.  This might have made sense when sending the COMMIT
required a separate action by the VFS/MM (e.g.  releasepage() used to
send a COMMIT).  However now that all writes generated by ->writepages()
will automatically be followed by a COMMIT (since commit 919e3bd9a8
("NFS: Ensure we commit after writeback is complete")) it makes more
sense to treat them as writeback pages.

So this patch removes NR_UNSTABLE_NFS and accounts unstable pages in
NR_WRITEBACK and WB_WRITEBACK.

A particular effect of this change is that when
wb_check_background_flush() calls wb_over_bg_threshold(), the latter
will report 'true' a lot less often as the 'unstable' pages are no
longer considered 'dirty' (as there is nothing that writeback can do
about them anyway).

Currently wb_check_background_flush() will trigger writeback to NFS even
when there are relatively few dirty pages (if there are lots of unstable
pages), this can result in small writes going to the server (10s of
Kilobytes rather than a Megabyte) which hurts throughput.  With this
patch, there are fewer writes which are each larger on average.

Where the NR_UNSTABLE_NFS count was included in statistics
virtual-files, the entry is retained, but the value is hard-coded as
zero.  static trace points and warning printks which mentioned this
counter no longer report it.

[akpm@linux-foundation.org: re-layout comment]
[akpm@linux-foundation.org: fix printk warning]
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Acked-by: Michal Hocko <mhocko@suse.com>	[mm]
Cc: Christoph Hellwig <hch@lst.de>
Cc: Chuck Lever <chuck.lever@oracle.com>
Link: http://lkml.kernel.org/r/87d06j7gqa.fsf@notabene.neil.brown.name
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-02 10:59:08 -07:00
..
kasan kasan: disable branch tracing for core runtime 2020-05-23 10:26:31 -07:00
backing-dev.c bdi: add a ->dev_name field to struct backing_dev_info 2020-05-09 16:07:57 -06:00
balloon_compaction.c mm/balloon_compaction: suppress allocation warnings 2019-09-04 07:42:01 -04:00
cleancache.c Driver Core and debugfs changes for 5.3-rc1 2019-07-12 12:24:03 -07:00
cma_debug.c mm/cma_debug.c: use DEFINE_DEBUGFS_ATTRIBUTE to define debugfs fops 2019-12-01 12:59:09 -08:00
cma.c mm: cma: NUMA node interface 2020-04-10 15:36:21 -07:00
cma.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
compaction.c mm/compaction: add missing annotation for compact_lock_irqsave 2020-04-07 10:43:41 -07:00
debug_page_ref.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
debug.c mm, dump_page(): do not crash with invalid mapping pointer 2020-06-02 10:59:06 -07:00
dmapool.c mm/dmapool.c: micro-optimisation remove unnecessary branch 2020-04-07 10:43:42 -07:00
early_ioremap.c mm/early_ioremap.c: use %pa to print resource_size_t variables 2020-01-31 10:30:38 -08:00
fadvise.c mm: return void from various readahead functions 2020-06-02 10:59:06 -07:00
failslab.c mm/failslab.c: by default, do not fail allocations with direct reclaim only 2019-07-12 11:05:43 -07:00
filemap.c mm/filemap.c: remove misleading comment 2020-06-02 10:59:08 -07:00
frame_vector.c mm: untag user pointers in get_vaddr_frames 2019-09-25 17:51:41 -07:00
frontswap.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 482 2019-06-19 17:09:52 +02:00
gup_benchmark.c mm/gup_benchmark: support pin_user_pages() and related calls 2020-04-02 09:35:27 -07:00
gup.c mm/gup: fix fixup_user_fault() on multiple retries 2020-05-14 10:00:35 -07:00
highmem.c mm, x86/mm: Untangle address space layout definitions from basic pgtable type definitions 2019-12-10 10:12:55 +01:00
hmm.c mm/hmm: return error for non-vma snapshots 2020-03-30 16:58:36 -03:00
huge_memory.c userfaultfd: wp: support swap and page migration 2020-04-07 10:43:39 -07:00
hugetlb_cgroup.c mm: use fallthrough; 2020-04-07 10:43:41 -07:00
hugetlb.c mm/hugetlb: fix a addressing exception caused by huge_pte_offset 2020-04-21 11:11:55 -07:00
hwpoison-inject.c mm/hwpoison-inject: use DEFINE_DEBUGFS_ATTRIBUTE to define debugfs fops 2019-12-01 12:59:09 -08:00
init-mm.c mm/init-mm.c: include <linux/mman.h> for vm_committed_as_batch 2019-10-19 06:32:32 -04:00
internal.h mm: return void from various readahead functions 2020-06-02 10:59:06 -07:00
interval_tree.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 248 2019-06-19 17:09:08 +02:00
Kconfig libnvdimm for 5.7 2020-04-08 21:03:40 -07:00
Kconfig.debug mm: add generic ptdump 2020-02-04 03:05:25 +00:00
khugepaged.c mm,thp: stop leaking unreleased file pages 2020-05-28 11:35:40 -07:00
kmemleak-test.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 333 2019-06-05 17:37:06 +02:00
kmemleak.c mm/kmemleak.c: use address-of operator on section symbols 2020-04-02 09:35:26 -07:00
ksm.c mm/ksm: fix NULL pointer dereference when KSM zero page is enabled 2020-04-21 11:11:55 -07:00
list_lru.c mm: use fallthrough; 2020-04-07 10:43:41 -07:00
maccess.c uaccess: Add strict non-pagefault kernel-space read function 2019-11-02 12:39:12 -07:00
madvise.c mm: check that mm is still valid in madvise() 2020-04-24 13:28:03 -07:00
Makefile mm: introduce Reported pages 2020-04-07 10:43:38 -07:00
mapping_dirty_helpers.c mm/mapping_dirty_helpers: update huge page-table entry callbacks 2020-04-02 09:35:29 -07:00
memblock.c mm: cma: NUMA node interface 2020-04-10 15:36:21 -07:00
memcontrol.c mm/writeback: discard NR_UNSTABLE_NFS, use NR_WRITEBACK instead 2020-06-02 10:59:08 -07:00
memfd.c mm: page cache: store only head pages in i_pages 2019-09-24 15:54:08 -07:00
memory_hotplug.c mm/memory_hotplug: add pgprot_t to mhp_params 2020-04-10 15:36:21 -07:00
memory-failure.c mm: code cleanup for MADV_FREE 2020-04-07 10:43:38 -07:00
memory.c mm/memory.c: add vm_insert_pages() 2020-04-10 15:36:21 -07:00
mempolicy.c libnvdimm for 5.7 2020-04-08 21:03:40 -07:00
mempool.c docs/core-api/mm: fix return value descriptions in mm/ 2019-03-05 21:07:20 -08:00
memremap.c mm/memremap: set caching mode for PCI P2PDMA memory to WC 2020-04-10 15:36:21 -07:00
memtest.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
migrate.c mm/migrate.c: call detach_page_private to cleanup code 2020-06-02 10:59:08 -07:00
mincore.c mm: pagewalk: add 'depth' parameter to pte_hole 2020-02-04 03:05:25 +00:00
mlock.c mm: untag user pointers passed to memory syscalls 2019-09-25 17:51:41 -07:00
mm_init.c mm/mm_init.c: clean code. Use BUILD_BUG_ON when comparing compile time constant 2020-04-07 10:43:41 -07:00
mmap.c mm/vma: introduce VM_ACCESS_FLAGS 2020-04-10 15:36:21 -07:00
mmu_context.c sched/headers: Prepare to move the task_lock()/unlock() APIs to <linux/sched/task.h> 2017-03-02 08:42:38 +01:00
mmu_gather.c asm-generic/tlb: provide MMU_GATHER_TABLE_FREE 2020-02-04 03:05:26 +00:00
mmu_notifier.c mm/mmu_notifier: silence PROVE_RCU_LIST warnings 2020-03-21 18:56:06 -07:00
mmzone.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mprotect.c mm/vma: introduce VM_ACCESS_FLAGS 2020-04-10 15:36:21 -07:00
mremap.c userfaultfd: fix remap event with MREMAP_DONTUNMAP 2020-05-14 10:00:35 -07:00
msync.c mm: untag user pointers passed to memory syscalls 2019-09-25 17:51:41 -07:00
nommu.c x86/mm: split vmalloc_sync_all() 2020-03-21 18:56:06 -07:00
oom_kill.c mm, oom: dump stack of victim when reaping failed 2020-01-31 10:30:38 -08:00
page_alloc.c mm/writeback: discard NR_UNSTABLE_NFS, use NR_WRITEBACK instead 2020-06-02 10:59:08 -07:00
page_counter.c mm, memcg: prevent memory.min load/store tearing 2020-04-02 09:35:29 -07:00
page_ext.c mm/page_ext.c: drop pfn_present() check when onlining 2020-04-07 10:43:40 -07:00
page_idle.c mm/page_idle.c: fix oops because end_pfn is larger than max_pfn 2019-06-29 16:43:45 +08:00
page_io.c fs: Enable bmap() function to properly return errors 2020-02-03 08:05:37 -05:00
page_isolation.c mm: add function __putback_isolated_page 2020-04-07 10:43:38 -07:00
page_owner.c mm/page_owner: don't access uninitialized memmaps when reading /proc/pagetypeinfo 2019-10-19 06:32:31 -04:00
page_poison.c mm/page_poison.c: fix a typo in a comment 2019-09-24 15:54:08 -07:00
page_reporting.c mm/page_reporting: add budget limit on how many pages can be reported per pass 2020-04-07 10:43:39 -07:00
page_reporting.h mm: introduce Reported pages 2020-04-07 10:43:38 -07:00
page_vma_mapped.c mm/page_vma_mapped.c: explicitly compare pfn for normal, hugetlbfs and THP page 2020-01-31 10:30:38 -08:00
page-writeback.c mm/writeback: discard NR_UNSTABLE_NFS, use NR_WRITEBACK instead 2020-06-02 10:59:08 -07:00
pagewalk.c x86: mm: avoid allocating struct mm_struct on the stack 2020-02-04 03:05:25 +00:00
percpu-internal.h percpu: convert chunk hints to be based on pcpu_block_md 2019-03-13 12:25:31 -07:00
percpu-km.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428 2019-06-05 17:37:16 +02:00
percpu-stats.c percpu: update copyright emails to dennis@kernel.org 2020-04-01 10:09:12 -07:00
percpu-vm.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428 2019-06-05 17:37:16 +02:00
percpu.c percpu: make pcpu_alloc() aware of current gfp context 2020-05-07 19:27:21 -07:00
pgtable-generic.c asm-generic/mm: stub out p{4,u}d_clear_bad() if __PAGETABLE_P{4,U}D_FOLDED 2019-12-01 06:29:19 -08:00
process_vm_access.c mm: docs: Fix a comment in process_vm_rw_core 2020-03-25 10:04:01 -05:00
ptdump.c x86: mm: avoid allocating struct mm_struct on the stack 2020-02-04 03:05:25 +00:00
readahead.c mm: use memalloc_nofs_save in readahead path 2020-06-02 10:59:07 -07:00
rmap.c mm: prevent a warning when casting void* -> enum 2020-04-07 10:43:41 -07:00
rodata_test.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441 2019-06-05 17:37:17 +02:00
shmem.c mm: shmem: disable interrupt when acquiring info->lock in userfaultfd_copy path 2020-04-21 11:11:56 -07:00
shuffle.c mm: adjust shuffle code to allow for future coalescing 2020-04-07 10:43:38 -07:00
shuffle.h mm: adjust shuffle code to allow for future coalescing 2020-04-07 10:43:38 -07:00
slab_common.c usercopy: mark dma-kmalloc caches as usercopy caches 2020-06-02 10:59:06 -07:00
slab.c mm, debug_pagealloc: don't rely on static keys too early 2020-01-13 18:19:02 -08:00
slab.h mm: kmem: rename (__)memcg_kmem_(un)charge_memcg() to __memcg_kmem_(un)charge() 2020-04-02 09:35:28 -07:00
slob.c mm, sl[aou]b: guarantee natural alignment for kmalloc(power-of-two) 2019-10-07 15:47:20 -07:00
slub.c mm/slub: fix stack overruns with SLUB_STATS 2020-06-02 10:59:06 -07:00
sparse-vmemmap.c mm/sparsemem: convert kmalloc_section_memmap() to populate_section_memmap() 2019-07-18 17:08:07 -07:00
sparse.c mm/sparse.c: move subsection_map related functions together 2020-04-07 10:43:40 -07:00
swap_cgroup.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
swap_slots.c mm/swap_slots.c: assign|reset cache slot by value directly 2020-04-02 09:35:27 -07:00
swap_state.c mm/swap_state.c: use the same way to count page in [add_to|delete_from]_swap_cache 2020-04-02 09:35:28 -07:00
swap.c mm: huge tmpfs: try to split_huge_page() when punching hole 2020-04-07 10:43:41 -07:00
swapfile.c proc: faster open/read/close with "permanent" files 2020-04-07 10:43:42 -07:00
truncate.c mm/thp: allow dropping THP from page cache 2019-10-19 06:32:33 -04:00
usercopy.c usercopy: Avoid HIGHMEM pfn warning 2019-09-17 15:20:17 -07:00
userfaultfd.c userfaultfd: wp: support write protection for userfault vma range 2020-04-07 10:43:39 -07:00
util.c mm/mmap.c: rb_parent is not necessary in __vma_link_list() 2019-12-01 06:29:19 -08:00
vmacache.c mm: get rid of vmacache_flush_all() entirely 2018-09-13 15:18:04 -10:00
vmalloc.c vmalloc: fix remap_vmalloc_range() bounds checks 2020-04-21 11:11:56 -07:00
vmpressure.c mm: vmpressure: use mem_cgroup_is_root API 2020-04-02 09:35:31 -07:00
vmscan.c mm/writeback: replace PF_LESS_THROTTLE with PF_LOCAL_THROTTLE 2020-06-02 10:59:08 -07:00
vmstat.c mm/writeback: discard NR_UNSTABLE_NFS, use NR_WRITEBACK instead 2020-06-02 10:59:08 -07:00
workingset.c mm: vmscan: detect file thrashing at the reclaim root 2019-12-01 12:59:07 -08:00
z3fold.c mm/z3fold: silence kmemleak false positives of slots 2020-05-28 11:35:40 -07:00
zbud.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
zpool.c zpool: add malloc_support_movable to zpool_driver 2019-09-24 15:54:12 -07:00
zsmalloc.c mm: use fallthrough; 2020-04-07 10:43:41 -07:00
zswap.c mm/zswap: allow setting default status, compressor and allocator in Kconfig 2020-04-07 10:43:41 -07:00