2021-09-25 06:22:28

by Eric Dumazet

[permalink] [raw]
Subject: [BUG] numa spreading of large hash tables no longer a thing

Hi Andrew and mm experts

It seems recent kernels lost the NUMA spreading of large hash tables
allocated at boot time.

Does it ring a bell, was it intentional ?
Thanks

Old behavior
otrv5:~# grep alloc_large_system_hash /proc/vmallocinfo
0x000000006381d67a-0x000000009bc8465a 12288
alloc_large_system_hash+0xf1/0x290 pages=2 vmalloc N0=1 N1=1
0x000000009bc8465a-0x00000000b70c6dfc 12288
alloc_large_system_hash+0xf1/0x290 pages=2 vmalloc N0=1 N1=1
0x00000000b70c6dfc-0x00000000ab13330f 12288
alloc_large_system_hash+0xf1/0x290 pages=2 vmalloc N0=1 N1=1
0x000000008685d551-0x000000009ce0c789 12288
alloc_large_system_hash+0xf1/0x290 pages=2 vmalloc N0=1 N1=1
0x000000004d87acca-0x00000000781b44e4 266240
alloc_large_system_hash+0xf1/0x290 pages=64 vmalloc N0=32 N1=32
0x00000000dea0f2d2-0x00000000909e9fb3 268439552
alloc_large_system_hash+0xf1/0x290 pages=65536 vmalloc vpages N0=32768
N1=32768
0x00000000909e9fb3-0x00000000d23f4353 528384
alloc_large_system_hash+0xf1/0x290 pages=128 vmalloc N0=64 N1=64
0x00000000d23f4353-0x000000003913e8bc 134221824
alloc_large_system_hash+0xf1/0x290 pages=32768 vmalloc vpages N0=16384
N1=16384
0x000000003913e8bc-0x000000007a60bcd6 4198400
alloc_large_system_hash+0xf1/0x290 pages=1024 vmalloc vpages N0=512
N1=512
0x000000007a60bcd6-0x0000000001bc8bf9 4198400
alloc_large_system_hash+0xf1/0x290 pages=1024 vmalloc vpages N0=512
N1=512
0x0000000001bc8bf9-0x0000000022629b89 4198400
alloc_large_system_hash+0xf1/0x290 pages=1024 vmalloc vpages N0=512
N1=512
0x0000000022629b89-0x0000000027d1b0a7 1052672
alloc_large_system_hash+0xf1/0x290 pages=256 vmalloc N0=128 N1=128
0x0000000027d1b0a7-0x0000000027310068 4198400
alloc_large_system_hash+0xf1/0x290 pages=1024 vmalloc vpages N0=512
N1=512
0x0000000027310068-0x00000000a845050a 1052672
alloc_large_system_hash+0xf1/0x290 pages=256 vmalloc N0=128 N1=128
0x00000000a845050a-0x0000000028b8c1bc 2101248
alloc_large_system_hash+0xf1/0x290 pages=512 vmalloc N0=256 N1=256
0x0000000028b8c1bc-0x000000002aff2d3d 2101248
alloc_large_system_hash+0xf1/0x290 pages=512 vmalloc N0=256 N1=256

New behavior
otrv6:~# grep alloc_large_system_hash /proc/vmallocinfo
0x00000000de22dded-0x000000006574cf88 12288
alloc_large_system_hash+0x18c/0x272 pages=2 vmalloc N0=2
0x000000006574cf88-0x00000000bc158a1d 12288
alloc_large_system_hash+0x18c/0x272 pages=2 vmalloc N0=2
0x00000000afa304a2-0x0000000009981fb8 12288
alloc_large_system_hash+0x18c/0x272 pages=2 vmalloc N0=2
0x00000000e3ab78c1-0x00000000ddbeadf2 528384
alloc_large_system_hash+0x18c/0x272 pages=128 vmalloc N0=128
0x0000000000cce551-0x0000000022096e73 12288
alloc_large_system_hash+0x18c/0x272 pages=2 vmalloc N0=2
0x0000000072a43217-0x00000000cf0c05f7 266240
alloc_large_system_hash+0x18c/0x272 pages=64 vmalloc N0=64
0x000000003f85e695-0x0000000042154f88 268439552
alloc_large_system_hash+0x18c/0x272 pages=65536 vmalloc vpages
N0=65536
0x0000000042154f88-0x0000000066fcdca2 134221824
alloc_large_system_hash+0x18c/0x272 pages=32768 vmalloc vpages
N0=32768
0x0000000066fcdca2-0x000000004074129c 4198400
alloc_large_system_hash+0x18c/0x272 pages=1024 vmalloc vpages N0=1024
0x000000004074129c-0x00000000ca32b7f9 4198400
alloc_large_system_hash+0x18c/0x272 pages=1024 vmalloc vpages N0=1024
0x00000000ca32b7f9-0x00000000a56b8117 4198400
alloc_large_system_hash+0x18c/0x272 pages=1024 vmalloc vpages N0=1024
0x00000000a56b8117-0x0000000089e9e39e 2101248
alloc_large_system_hash+0x18c/0x272 pages=512 vmalloc N0=512
0x0000000089e9e39e-0x0000000090a80b5a 1052672
alloc_large_system_hash+0x18c/0x272 pages=256 vmalloc N0=256
0x0000000090a80b5a-0x00000000e84776cb 4198400
alloc_large_system_hash+0x18c/0x272 pages=1024 vmalloc vpages N0=1024
0x00000000e84776cb-0x000000006cfc05bf 1052672
alloc_large_system_hash+0x18c/0x272 pages=256 vmalloc N0=256
0x000000006cfc05bf-0x00000000f6ce3623 1576960
alloc_large_system_hash+0x18c/0x272 pages=384 vmalloc N0=384
0x00000000f6ce3623-0x0000000002737823 2101248
alloc_large_system_hash+0x18c/0x272 pages=512 vmalloc N0=512
0x0000000002737823-0x00000000d4e74269 2101248
alloc_large_system_hash+0x18c/0x272 pages=512 vmalloc N0=512


2021-09-25 15:55:59

by Eric Dumazet

[permalink] [raw]
Subject: Re: [BUG] numa spreading of large hash tables no longer a thing

On Fri, Sep 24, 2021 at 12:55 PM Eric Dumazet <[email protected]> wrote:
>
> Hi Andrew and mm experts
>
> It seems recent kernels lost the NUMA spreading of large hash tables
> allocated at boot time.
>
> Does it ring a bell, was it intentional ?
> Thanks

I did a bisection and it went back to the following commit [1]

Probably the removal of

- if (node == NUMA_NO_NODE)
- page = alloc_page(gfp_mask);
- else
- page = alloc_pages_node(node, gfp_mask, 0);

had something to do with the regression.

Things got a little bit more complicated after the introduction of
bulk allocations.

[1]
commit 121e6f3258fe393e22c36f61a319be8a4f2c05ae
Author: Nicholas Piggin <[email protected]>
Date: Thu Apr 29 22:58:49 2021 -0700

mm/vmalloc: hugepage vmalloc mappings

Support huge page vmalloc mappings. Config option HAVE_ARCH_HUGE_VMALLOC
enables support on architectures that define HAVE_ARCH_HUGE_VMAP and
supports PMD sized vmap mappings.

vmalloc will attempt to allocate PMD-sized pages if allocating PMD size or
larger, and fall back to small pages if that was unsuccessful.

Architectures must ensure that any arch specific vmalloc allocations that
require PAGE_SIZE mappings (e.g., module allocations vs strict module rwx)
use the VM_NOHUGE flag to inhibit larger mappings.

This can result in more internal fragmentation and memory overhead for a
given allocation, an option nohugevmalloc is added to disable at boot.

[[email protected]: fix read of uninitialized pointer area]
Link: https://lkml.kernel.org/r/[email protected]

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Nicholas Piggin <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: Ding Tianhong <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Miaohe Lin <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Russell King <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Uladzislau Rezki (Sony) <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

arch/Kconfig | 11 +++
include/linux/vmalloc.h | 21 +++++
mm/page_alloc.c | 5 +-
mm/vmalloc.c | 220 +++++++++++++++++++++++++++++++++++++-----------
4 files changed, 209 insertions(+), 48 deletions(-)

>
> Old behavior
> otrv5:~# grep alloc_large_system_hash /proc/vmallocinfo
> 0x000000006381d67a-0x000000009bc8465a 12288
> alloc_large_system_hash+0xf1/0x290 pages=2 vmalloc N0=1 N1=1
> 0x000000009bc8465a-0x00000000b70c6dfc 12288
> alloc_large_system_hash+0xf1/0x290 pages=2 vmalloc N0=1 N1=1
> 0x00000000b70c6dfc-0x00000000ab13330f 12288
> alloc_large_system_hash+0xf1/0x290 pages=2 vmalloc N0=1 N1=1
> 0x000000008685d551-0x000000009ce0c789 12288
> alloc_large_system_hash+0xf1/0x290 pages=2 vmalloc N0=1 N1=1
> 0x000000004d87acca-0x00000000781b44e4 266240
> alloc_large_system_hash+0xf1/0x290 pages=64 vmalloc N0=32 N1=32
> 0x00000000dea0f2d2-0x00000000909e9fb3 268439552
> alloc_large_system_hash+0xf1/0x290 pages=65536 vmalloc vpages N0=32768
> N1=32768
> 0x00000000909e9fb3-0x00000000d23f4353 528384
> alloc_large_system_hash+0xf1/0x290 pages=128 vmalloc N0=64 N1=64
> 0x00000000d23f4353-0x000000003913e8bc 134221824
> alloc_large_system_hash+0xf1/0x290 pages=32768 vmalloc vpages N0=16384
> N1=16384
> 0x000000003913e8bc-0x000000007a60bcd6 4198400
> alloc_large_system_hash+0xf1/0x290 pages=1024 vmalloc vpages N0=512
> N1=512
> 0x000000007a60bcd6-0x0000000001bc8bf9 4198400
> alloc_large_system_hash+0xf1/0x290 pages=1024 vmalloc vpages N0=512
> N1=512
> 0x0000000001bc8bf9-0x0000000022629b89 4198400
> alloc_large_system_hash+0xf1/0x290 pages=1024 vmalloc vpages N0=512
> N1=512
> 0x0000000022629b89-0x0000000027d1b0a7 1052672
> alloc_large_system_hash+0xf1/0x290 pages=256 vmalloc N0=128 N1=128
> 0x0000000027d1b0a7-0x0000000027310068 4198400
> alloc_large_system_hash+0xf1/0x290 pages=1024 vmalloc vpages N0=512
> N1=512
> 0x0000000027310068-0x00000000a845050a 1052672
> alloc_large_system_hash+0xf1/0x290 pages=256 vmalloc N0=128 N1=128
> 0x00000000a845050a-0x0000000028b8c1bc 2101248
> alloc_large_system_hash+0xf1/0x290 pages=512 vmalloc N0=256 N1=256
> 0x0000000028b8c1bc-0x000000002aff2d3d 2101248
> alloc_large_system_hash+0xf1/0x290 pages=512 vmalloc N0=256 N1=256
>
> New behavior
> otrv6:~# grep alloc_large_system_hash /proc/vmallocinfo
> 0x00000000de22dded-0x000000006574cf88 12288
> alloc_large_system_hash+0x18c/0x272 pages=2 vmalloc N0=2
> 0x000000006574cf88-0x00000000bc158a1d 12288
> alloc_large_system_hash+0x18c/0x272 pages=2 vmalloc N0=2
> 0x00000000afa304a2-0x0000000009981fb8 12288
> alloc_large_system_hash+0x18c/0x272 pages=2 vmalloc N0=2
> 0x00000000e3ab78c1-0x00000000ddbeadf2 528384
> alloc_large_system_hash+0x18c/0x272 pages=128 vmalloc N0=128
> 0x0000000000cce551-0x0000000022096e73 12288
> alloc_large_system_hash+0x18c/0x272 pages=2 vmalloc N0=2
> 0x0000000072a43217-0x00000000cf0c05f7 266240
> alloc_large_system_hash+0x18c/0x272 pages=64 vmalloc N0=64
> 0x000000003f85e695-0x0000000042154f88 268439552
> alloc_large_system_hash+0x18c/0x272 pages=65536 vmalloc vpages
> N0=65536
> 0x0000000042154f88-0x0000000066fcdca2 134221824
> alloc_large_system_hash+0x18c/0x272 pages=32768 vmalloc vpages
> N0=32768
> 0x0000000066fcdca2-0x000000004074129c 4198400
> alloc_large_system_hash+0x18c/0x272 pages=1024 vmalloc vpages N0=1024
> 0x000000004074129c-0x00000000ca32b7f9 4198400
> alloc_large_system_hash+0x18c/0x272 pages=1024 vmalloc vpages N0=1024
> 0x00000000ca32b7f9-0x00000000a56b8117 4198400
> alloc_large_system_hash+0x18c/0x272 pages=1024 vmalloc vpages N0=1024
> 0x00000000a56b8117-0x0000000089e9e39e 2101248
> alloc_large_system_hash+0x18c/0x272 pages=512 vmalloc N0=512
> 0x0000000089e9e39e-0x0000000090a80b5a 1052672
> alloc_large_system_hash+0x18c/0x272 pages=256 vmalloc N0=256
> 0x0000000090a80b5a-0x00000000e84776cb 4198400
> alloc_large_system_hash+0x18c/0x272 pages=1024 vmalloc vpages N0=1024
> 0x00000000e84776cb-0x000000006cfc05bf 1052672
> alloc_large_system_hash+0x18c/0x272 pages=256 vmalloc N0=256
> 0x000000006cfc05bf-0x00000000f6ce3623 1576960
> alloc_large_system_hash+0x18c/0x272 pages=384 vmalloc N0=384
> 0x00000000f6ce3623-0x0000000002737823 2101248
> alloc_large_system_hash+0x18c/0x272 pages=512 vmalloc N0=512
> 0x0000000002737823-0x00000000d4e74269 2101248
> alloc_large_system_hash+0x18c/0x272 pages=512 vmalloc N0=512