From: "Cao, Quanquan/曹 全全" <caoqq@fujitsu.com>
To: dan.j.williams@intel.com, dave.jiang@intel.com, vishal.l.verma@intel.com
Cc: linux-cxl@vger.kernel.org
Subject: Question about a segmentation fault issue when accessing memory in a region
Date: Tue, 6 Feb 2024 15:38:31 +0800 [thread overview]
Message-ID: <3e84b919-7631-d1db-3e1d-33000f3f3868@fujitsu.com> (raw)
Hi, guys:
I tried to create a region on the 2hb+6mem environment.
Fortunately, the region was created successfully,
and the system memory can be seen in the system that
the system memory has increased.
When I tried to use the memory on the region, a segfault occurred.
anyone has idea?
Environment info:
os version: fedora 39
linux version: 6.7-rc5
qemu version: v8.2.0-rc4
kvm: off
The detailed operation commands are as follows.
========> Before region creation
# numactl -H
available: 2 nodes (0-1)
node 0 cpus: 0 1
node 0 size: 1006 MB
node 0 free: 624 MB
node 1 cpus: 2 3
node 1 size: 899 MB
node 1 free: 694 MB
node distances:
node 0 1
0: 10 20
1: 20 10
# free -h
total used free shared buff/cache
available
Mem: 1.9Gi 448Mi 1.3Gi 1.1Mi 330Mi
1.4Gi
Swap: 1.9Gi 0B 1.9Gi
========> create a new region
# echo online_movable > /sys/devices/system/memory/auto_online_blocks
# cxl list -M -P -D -T -E -u
[
{
"ports":[
{
"port":"port1",
"host":"pci0000:20",
"depth":1,
"nr_dports":2,
"dports":[
{
"dport":"0000:20:00.0",
"id":"0"
},
{
"dport":"0000:20:01.0",
"id":"0x1"
}
],
"endpoints:port1":[
{
"endpoint":"endpoint5",
"host":"mem1",
"parent_dport":"0000:20:01.0",
"depth":2,
"memdev":{
"memdev":"mem1",
"ram_size":"256.00 MiB (268.44 MB)",
"serial":"0",
"host":"0000:22:00.0"
}
},
{
"endpoint":"endpoint4",
"host":"mem0",
"parent_dport":"0000:20:00.0",
"depth":2,
"memdev":{
"memdev":"mem0",
"ram_size":"256.00 MiB (268.44 MB)",
"serial":"0",
"host":"0000:21:00.0"
}
}
]
},
{
"port":"port3",
"host":"pci0000:0c",
"depth":1,
"nr_dports":2,
"dports":[
{
"dport":"0000:0c:00.0",
"id":"0"
},
{
"dport":"0000:0c:01.0",
"id":"0x1"
}
],
"endpoints:port3":[
{
"endpoint":"endpoint7",
"host":"mem3",
"parent_dport":"0000:0c:00.0",
"depth":2,
"memdev":{
"memdev":"mem3",
"ram_size":"256.00 MiB (268.44 MB)",
"serial":"0",
"host":"0000:0d:00.0"
}
},
{
"endpoint":"endpoint9",
"host":"mem5",
"parent_dport":"0000:0c:01.0",
"depth":2,
"memdev":{
"memdev":"mem5",
"ram_size":"256.00 MiB (268.44 MB)",
"serial":"0",
"host":"0000:0e:00.0"
}
}
]
},
{
"port":"port2",
"host":"pci0000:16",
"depth":1,
"nr_dports":2,
"dports":[
{
"dport":"0000:16:00.0",
"id":"0"
},
{
"dport":"0000:16:01.0",
"id":"0x1"
}
],
"endpoints:port2":[
{
"endpoint":"endpoint6",
"host":"mem2",
"parent_dport":"0000:16:01.0",
"depth":2,
"memdev":{
"memdev":"mem2",
"ram_size":"256.00 MiB (268.44 MB)",
"serial":"0",
"host":"0000:18:00.0"
}
},
{
"endpoint":"endpoint8",
"host":"mem4",
"parent_dport":"0000:16:00.0",
"depth":2,
"memdev":{
"memdev":"mem4",
"ram_size":"256.00 MiB (268.44 MB)",
"serial":"0",
"host":"0000:17:00.0"
}
}
]
}
]
},
{
"root decoders":[
{
"decoder":"decoder0.0",
"resource":"0x750000000",
"size":"4.00 GiB (4.29 GB)",
"interleave_ways":3,
"interleave_granularity":4096,
"max_available_extent":"4.00 GiB (4.29 GB)",
"pmem_capable":true,
"volatile_capable":true,
"accelmem_capable":true,
"nr_targets":3,
"targets":[
{
"target":"pci0000:20",
"alias":"ACPI0016:00",
"position":2,
"id":"0x20"
},
{
"target":"pci0000:16",
"alias":"ACPI0016:01",
"position":1,
"id":"0x16"
},
{
"target":"pci0000:0c",
"alias":"ACPI0016:02",
"position":0,
"id":"0xc"
}
]
}
]
}
]
# cxl create-region -t ram -d decoder0.0 -m mem3 mem2 mem1 mem5 mem4 mem0
{
"region":"region0",
"resource":"0x750000000",
"size":"1536.00 MiB (1610.61 MB)",
"type":"ram",
"interleave_ways":6,
"interleave_granularity":4096,
"decode_state":"commit",
"mappings":[
{
"position":5,
"memdev":"mem0",
"decoder":"decoder4.0"
},
{
"position":4,
"memdev":"mem4",
"decoder":"decoder8.0"
},
{
"position":3,
"memdev":"mem5",
"decoder":"decoder9.0"
},
{
"position":2,
"memdev":"mem1",
"decoder":"decoder5.0"
},
{
"position":1,
"memdev":"mem2",
"decoder":"decoder6.0"
},
{
"position":0,
"memdev":"mem3",
"decoder":"decoder7.0"
}
]
}
cxl region: cmd_create_region: created 1 region
===> After region creation
# numactl -H
available: 3 nodes (0-2)
node 0 cpus: 0 1
node 0 size: 1006 MB
node 0 free: 736 MB
node 1 cpus: 2 3
node 1 size: 899 MB
node 1 free: 548 MB
node 2 cpus:
node 2 size: 1536 MB <-- new numa node was create
node 2 free: 1536 MB
node distances:
node 0 1 2
0: 10 20 20
1: 20 10 20
2: 20 20 10
# free -h <-- System memory increased
total used free shared buff/cache
available
Mem: 3.4Gi 504Mi 2.8Gi 1.1Mi 338Mi
2.9Gi
Swap: 1.9Gi 0B 1.9Gi
# numactl --membind=2 ls
Segmentation fault (core dumped)
# dmesg
[ 310.119439] show_signal_msg: 20 callbacks suppressed
[ 310.119499] ls[1153]: segfault at 1c454 ip 00007fb4cf771523 sp
00007fff57753fe0 error 4 in ld-linux-x86-64.so.2[7fb4cf753000+27000]
likely on CPU 2 (core 0, socket 2)
[ 310.350803] Code: 01 42 08 48 8b bd 98 fd ff ff 48 8b 57 70 48 85 d2
74 04 48 01 42 08 48 8b bd 98 fd ff ff 48 8b 97 60 01 00 00 48 85 d2 74
04 <48> 01 42 08 48 8b bd 98 fd ff ff 48 8b 8f f8 00 00 00 48 85 c9 74
next reply other threads:[~2024-02-06 7:38 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-02-06 7:38 Cao, Quanquan/曹 全全 [this message]
2024-02-06 8:00 ` Question about a segmentation fault issue when accessing memory in a region Cao, Quanquan/曹 全全
2024-02-06 10:17 ` Jonathan Cameron
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=3e84b919-7631-d1db-3e1d-33000f3f3868@fujitsu.com \
--to=caoqq@fujitsu.com \
--cc=dan.j.williams@intel.com \
--cc=dave.jiang@intel.com \
--cc=linux-cxl@vger.kernel.org \
--cc=vishal.l.verma@intel.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox