tools/cgroup/iocost_monitor.py
Source file repositories/reference/linux-study-clean/tools/cgroup/iocost_monitor.py
File Facts
- System
- Linux kernel
- Corpus path
tools/cgroup/iocost_monitor.py- Extension
.py- Size
- 9865 bytes
- Lines
- 278
- Domain
- Support Tooling And Documentation
- Bucket
- tools
- Inferred role
- Support Tooling And Documentation: tools
- Status
- atlas-only
Why This File Exists
Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.
- Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.
- Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.
Dependency Surface
- No C-style include directives detected by the generator.
Detected Declarations
- No top-level syscall, struct, function, initcall, or export declaration detected by the generator.
Annotated Snippet
#!/usr/bin/env drgn
#
# Copyright (C) 2019 Tejun Heo <tj@kernel.org>
# Copyright (C) 2019 Facebook
desc = """
This is a drgn script to monitor the blk-iocost cgroup controller.
See the comment at the top of block/blk-iocost.c for more details.
For drgn, visit https://github.com/osandov/drgn.
"""
import sys
import re
import time
import json
import math
import drgn
from drgn import container_of
from drgn.helpers.linux.list import list_for_each_entry,list_empty
from drgn.helpers.linux.radixtree import radix_tree_for_each,radix_tree_lookup
import argparse
parser = argparse.ArgumentParser(description=desc,
formatter_class=argparse.RawTextHelpFormatter)
parser.add_argument('devname', metavar='DEV',
help='Target block device name (e.g. sda)')
parser.add_argument('--cgroup', action='append', metavar='REGEX',
help='Regex for target cgroups, ')
parser.add_argument('--interval', '-i', metavar='SECONDS', type=float, default=1,
help='Monitoring interval in seconds (0 exits immediately '
'after checking requirements)')
parser.add_argument('--json', action='store_true',
help='Output in json')
args = parser.parse_args()
def err(s):
print(s, file=sys.stderr, flush=True)
sys.exit(1)
try:
blkcg_root = prog['blkcg_root']
plid = prog['blkcg_policy_iocost'].plid.value_()
except:
err('The kernel does not have iocost enabled')
IOC_RUNNING = prog['IOC_RUNNING'].value_()
WEIGHT_ONE = prog['WEIGHT_ONE'].value_()
VTIME_PER_SEC = prog['VTIME_PER_SEC'].value_()
VTIME_PER_USEC = prog['VTIME_PER_USEC'].value_()
AUTOP_SSD_FAST = prog['AUTOP_SSD_FAST'].value_()
AUTOP_SSD_DFL = prog['AUTOP_SSD_DFL'].value_()
AUTOP_SSD_QD1 = prog['AUTOP_SSD_QD1'].value_()
AUTOP_HDD = prog['AUTOP_HDD'].value_()
autop_names = {
AUTOP_SSD_FAST: 'ssd_fast',
AUTOP_SSD_DFL: 'ssd_dfl',
AUTOP_SSD_QD1: 'ssd_qd1',
AUTOP_HDD: 'hdd',
}
class BlkgIterator:
def __init__(self, root_blkcg, q_id, include_dying=False):
self.include_dying = include_dying
self.blkgs = []
self.walk(root_blkcg, q_id, '')
def blkcg_name(blkcg):
return blkcg.css.cgroup.kn.name.string_().decode('utf-8')
Annotation
- Atlas domain: Support Tooling And Documentation / tools.
- Implementation status: atlas-only.
Implementation Notes
- This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
- Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
- Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.