merge-sort step pre-alloc too many memory

[D3Hunter]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

import 10t data on 5 16c32g nodes, during merge-sort step some node take too many memory

node0/1/3 oom, memory usage of 2/4 is normal

2. What did you expect to see? (Required)

3. What did you see instead (Required)

4. What is your TiDB version? (Required)

with this pr #48277

| Release Version: v7.6.0-test
Edition: Community
Git Commit Hash: 73afea0396530cad3dde87cd5ea1be77f461e793
Git Branch: heads/refs/tags/v7.6.0-test
UTC Build Time: 2023-11-06 14:44:17
GoVersion: go1.21.3
Race Enabled: false
Check Table Before Drop: false
Store: tikv |
+-----------------------------------

[D3Hunter]

we're using MemTotal to get total memory, which is init as MemTotalNormal as InContainer only checks a few keywords. so the calculated memory is too large.

tidb/pkg/util/cgroup/cgroup_cpu_linux.go

Lines 64 to 66 in 662528d

	if strings.Contains(string(v), "docker") ||
	strings.Contains(string(v), "kubepods") ||
	strings.Contains(string(v), "containerd") {

here is the result of /proc/self/cgroup

tc-tidb-0
0::/
tc-tidb-1
1:name=systemd:/
0::/
tc-tidb-2
12:pids:/kubepods.slice/kubepods-pod8b980b2a_d5be_4388_9b76_597c6bb4d4e2.slice/cri-containerd-0a636d4ed110533bcbbce02c840ad554b57b68a4b299f0bd14e018fef22cb59c.scope
11:rdma:/kubepods.slice/kubepods-pod8b980b2a_d5be_4388_9b76_597c6bb4d4e2.slice/cri-containerd-0a636d4ed110533bcbbce02c840ad554b57b68a4b299f0bd14e018fef22cb59c.scope
10:hugetlb:/kubepods.slice/kubepods-pod8b980b2a_d5be_4388_9b76_597c6bb4d4e2.slice/cri-containerd-0a636d4ed110533bcbbce02c840ad554b57b68a4b299f0bd14e018fef22cb59c.scope
9:cpuset:/kubepods.slice/kubepods-pod8b980b2a_d5be_4388_9b76_597c6bb4d4e2.slice/cri-containerd-0a636d4ed110533bcbbce02c840ad554b57b68a4b299f0bd14e018fef22cb59c.scope
8:net_cls,net_prio:/kubepods.slice/kubepods-pod8b980b2a_d5be_4388_9b76_597c6bb4d4e2.slice/cri-containerd-0a636d4ed110533bcbbce02c840ad554b57b68a4b299f0bd14e018fef22cb59c.scope
7:blkio:/kubepods.slice/kubepods-pod8b980b2a_d5be_4388_9b76_597c6bb4d4e2.slice/cri-containerd-0a636d4ed110533bcbbce02c840ad554b57b68a4b299f0bd14e018fef22cb59c.scope
6:freezer:/kubepods.slice/kubepods-pod8b980b2a_d5be_4388_9b76_597c6bb4d4e2.slice/cri-containerd-0a636d4ed110533bcbbce02c840ad554b57b68a4b299f0bd14e018fef22cb59c.scope
5:perf_event:/kubepods.slice/kubepods-pod8b980b2a_d5be_4388_9b76_597c6bb4d4e2.slice/cri-containerd-0a636d4ed110533bcbbce02c840ad554b57b68a4b299f0bd14e018fef22cb59c.scope
4:devices:/kubepods.slice/kubepods-pod8b980b2a_d5be_4388_9b76_597c6bb4d4e2.slice/cri-containerd-0a636d4ed110533bcbbce02c840ad554b57b68a4b299f0bd14e018fef22cb59c.scope
3:cpu,cpuacct:/kubepods.slice/kubepods-pod8b980b2a_d5be_4388_9b76_597c6bb4d4e2.slice/cri-containerd-0a636d4ed110533bcbbce02c840ad554b57b68a4b299f0bd14e018fef22cb59c.scope
2:memory:/kubepods.slice/kubepods-pod8b980b2a_d5be_4388_9b76_597c6bb4d4e2.slice/cri-containerd-0a636d4ed110533bcbbce02c840ad554b57b68a4b299f0bd14e018fef22cb59c.scope
1:name=systemd:/kubepods.slice/kubepods-pod8b980b2a_d5be_4388_9b76_597c6bb4d4e2.slice/cri-containerd-0a636d4ed110533bcbbce02c840ad554b57b68a4b299f0bd14e018fef22cb59c.scope
0::/
tc-tidb-3
222:name=systemd:/
0::/
tc-tidb-4
12:devices:/kubepods.slice/kubepods-pod46be7f8f_2fbd_4130_bfeb_953636dcd12c.slice/cri-containerd-92f0b5f187e11536fe62816fc14c493200851a6d8910ddacd0c844a660c15e95.scope
11:cpuset:/kubepods.slice/kubepods-pod46be7f8f_2fbd_4130_bfeb_953636dcd12c.slice/cri-containerd-92f0b5f187e11536fe62816fc14c493200851a6d8910ddacd0c844a660c15e95.scope
10:pids:/kubepods.slice/kubepods-pod46be7f8f_2fbd_4130_bfeb_953636dcd12c.slice/cri-containerd-92f0b5f187e11536fe62816fc14c493200851a6d8910ddacd0c844a660c15e95.scope
9:hugetlb:/kubepods.slice/kubepods-pod46be7f8f_2fbd_4130_bfeb_953636dcd12c.slice/cri-containerd-92f0b5f187e11536fe62816fc14c493200851a6d8910ddacd0c844a660c15e95.scope
8:perf_event:/kubepods.slice/kubepods-pod46be7f8f_2fbd_4130_bfeb_953636dcd12c.slice/cri-containerd-92f0b5f187e11536fe62816fc14c493200851a6d8910ddacd0c844a660c15e95.scope
7:rdma:/kubepods.slice/kubepods-pod46be7f8f_2fbd_4130_bfeb_953636dcd12c.slice/cri-containerd-92f0b5f187e11536fe62816fc14c493200851a6d8910ddacd0c844a660c15e95.scope
6:blkio:/kubepods.slice/kubepods-pod46be7f8f_2fbd_4130_bfeb_953636dcd12c.slice/cri-containerd-92f0b5f187e11536fe62816fc14c493200851a6d8910ddacd0c844a660c15e95.scope
5:memory:/kubepods.slice/kubepods-pod46be7f8f_2fbd_4130_bfeb_953636dcd12c.slice/cri-containerd-92f0b5f187e11536fe62816fc14c493200851a6d8910ddacd0c844a660c15e95.scope
4:net_cls,net_prio:/kubepods.slice/kubepods-pod46be7f8f_2fbd_4130_bfeb_953636dcd12c.slice/cri-containerd-92f0b5f187e11536fe62816fc14c493200851a6d8910ddacd0c844a660c15e95.scope
3:freezer:/kubepods.slice/kubepods-pod46be7f8f_2fbd_4130_bfeb_953636dcd12c.slice/cri-containerd-92f0b5f187e11536fe62816fc14c493200851a6d8910ddacd0c844a660c15e95.scope
2:cpu,cpuacct:/kubepods.slice/kubepods-pod46be7f8f_2fbd_4130_bfeb_953636dcd12c.slice/cri-containerd-92f0b5f187e11536fe62816fc14c493200851a6d8910ddacd0c844a660c15e95.scope
1:name=systemd:/kubepods.slice/kubepods-pod46be7f8f_2fbd_4130_bfeb_953636dcd12c.slice/cri-containerd-92f0b5f187e11536fe62816fc14c493200851a6d8910ddacd0c844a660c15e95.scope
0::/