Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/tools/cgroup/iocost_coef_gen.py b/tools/cgroup/iocost_coef_gen.py
new file mode 100644
index 0000000..df17a2a
--- /dev/null
+++ b/tools/cgroup/iocost_coef_gen.py
@@ -0,0 +1,178 @@
+#!/usr/bin/env python3
+#
+# Copyright (C) 2019 Tejun Heo <tj@kernel.org>
+# Copyright (C) 2019 Andy Newell <newella@fb.com>
+# Copyright (C) 2019 Facebook
+
+desc = """
+Generate linear IO cost model coefficients used by the blk-iocost
+controller.  If the target raw testdev is specified, destructive tests
+are performed against the whole device; otherwise, on
+./iocost-coef-fio.testfile.  The result can be written directly to
+/sys/fs/cgroup/io.cost.model.
+
+On high performance devices, --numjobs > 1 is needed to achieve
+saturation.
+
+See Documentation/admin-guide/cgroup-v2.rst and block/blk-iocost.c
+for more details.
+"""
+
+import argparse
+import re
+import json
+import glob
+import os
+import sys
+import atexit
+import shutil
+import tempfile
+import subprocess
+
+parser = argparse.ArgumentParser(description=desc,
+                                 formatter_class=argparse.RawTextHelpFormatter)
+parser.add_argument('--testdev', metavar='DEV',
+                    help='Raw block device to use for testing, ignores --testfile-size')
+parser.add_argument('--testfile-size-gb', type=float, metavar='GIGABYTES', default=16,
+                    help='Testfile size in gigabytes (default: %(default)s)')
+parser.add_argument('--duration', type=int, metavar='SECONDS', default=120,
+                    help='Individual test run duration in seconds (default: %(default)s)')
+parser.add_argument('--seqio-block-mb', metavar='MEGABYTES', type=int, default=128,
+                    help='Sequential test block size in megabytes (default: %(default)s)')
+parser.add_argument('--seq-depth', type=int, metavar='DEPTH', default=64,
+                    help='Sequential test queue depth (default: %(default)s)')
+parser.add_argument('--rand-depth', type=int, metavar='DEPTH', default=64,
+                    help='Random test queue depth (default: %(default)s)')
+parser.add_argument('--numjobs', type=int, metavar='JOBS', default=1,
+                    help='Number of parallel fio jobs to run (default: %(default)s)')
+parser.add_argument('--quiet', action='store_true')
+parser.add_argument('--verbose', action='store_true')
+
+def info(msg):
+    if not args.quiet:
+        print(msg)
+
+def dbg(msg):
+    if args.verbose and not args.quiet:
+        print(msg)
+
+# determine ('DEVNAME', 'MAJ:MIN') for @path
+def dir_to_dev(path):
+    # find the block device the current directory is on
+    devname = subprocess.run(f'findmnt -nvo SOURCE -T{path}',
+                             stdout=subprocess.PIPE, shell=True).stdout
+    devname = os.path.basename(devname).decode('utf-8').strip()
+
+    # partition -> whole device
+    parents = glob.glob('/sys/block/*/' + devname)
+    if len(parents):
+        devname = os.path.basename(os.path.dirname(parents[0]))
+    rdev = os.stat(f'/dev/{devname}').st_rdev
+    return (devname, f'{os.major(rdev)}:{os.minor(rdev)}')
+
+def create_testfile(path, size):
+    global args
+
+    if os.path.isfile(path) and os.stat(path).st_size == size:
+        return
+
+    info(f'Creating testfile {path}')
+    subprocess.check_call(f'rm -f {path}', shell=True)
+    subprocess.check_call(f'touch {path}', shell=True)
+    subprocess.call(f'chattr +C {path}', shell=True)
+    subprocess.check_call(
+        f'pv -s {size} -pr /dev/urandom {"-q" if args.quiet else ""} | '
+        f'dd of={path} count={size} '
+        f'iflag=count_bytes,fullblock oflag=direct bs=16M status=none',
+        shell=True)
+
+def run_fio(testfile, duration, iotype, iodepth, blocksize, jobs):
+    global args
+
+    eta = 'never' if args.quiet else 'always'
+    outfile = tempfile.NamedTemporaryFile()
+    cmd = (f'fio --direct=1 --ioengine=libaio --name=coef '
+           f'--filename={testfile} --runtime={round(duration)} '
+           f'--readwrite={iotype} --iodepth={iodepth} --blocksize={blocksize} '
+           f'--eta={eta} --output-format json --output={outfile.name} '
+           f'--time_based --numjobs={jobs}')
+    if args.verbose:
+        dbg(f'Running {cmd}')
+    subprocess.check_call(cmd, shell=True)
+    with open(outfile.name, 'r') as f:
+        d = json.loads(f.read())
+    return sum(j['read']['bw_bytes'] + j['write']['bw_bytes'] for j in d['jobs'])
+
+def restore_elevator_nomerges():
+    global elevator_path, nomerges_path, elevator, nomerges
+
+    info(f'Restoring elevator to {elevator} and nomerges to {nomerges}')
+    with open(elevator_path, 'w') as f:
+        f.write(elevator)
+    with open(nomerges_path, 'w') as f:
+        f.write(nomerges)
+
+
+args = parser.parse_args()
+
+missing = False
+for cmd in [ 'findmnt', 'pv', 'dd', 'fio' ]:
+    if not shutil.which(cmd):
+        print(f'Required command "{cmd}" is missing', file=sys.stderr)
+        missing = True
+if missing:
+    sys.exit(1)
+
+if args.testdev:
+    devname = os.path.basename(args.testdev)
+    rdev = os.stat(f'/dev/{devname}').st_rdev
+    devno = f'{os.major(rdev)}:{os.minor(rdev)}'
+    testfile = f'/dev/{devname}'
+    info(f'Test target: {devname}({devno})')
+else:
+    devname, devno = dir_to_dev('.')
+    testfile = 'iocost-coef-fio.testfile'
+    testfile_size = int(args.testfile_size_gb * 2 ** 30)
+    create_testfile(testfile, testfile_size)
+    info(f'Test target: {testfile} on {devname}({devno})')
+
+elevator_path = f'/sys/block/{devname}/queue/scheduler'
+nomerges_path = f'/sys/block/{devname}/queue/nomerges'
+
+with open(elevator_path, 'r') as f:
+    elevator = re.sub(r'.*\[(.*)\].*', r'\1', f.read().strip())
+with open(nomerges_path, 'r') as f:
+    nomerges = f.read().strip()
+
+info(f'Temporarily disabling elevator and merges')
+atexit.register(restore_elevator_nomerges)
+with open(elevator_path, 'w') as f:
+    f.write('none')
+with open(nomerges_path, 'w') as f:
+    f.write('1')
+
+info('Determining rbps...')
+rbps = run_fio(testfile, args.duration, 'read',
+               1, args.seqio_block_mb * (2 ** 20), args.numjobs)
+info(f'\nrbps={rbps}, determining rseqiops...')
+rseqiops = round(run_fio(testfile, args.duration, 'read',
+                         args.seq_depth, 4096, args.numjobs) / 4096)
+info(f'\nrseqiops={rseqiops}, determining rrandiops...')
+rrandiops = round(run_fio(testfile, args.duration, 'randread',
+                          args.rand_depth, 4096, args.numjobs) / 4096)
+info(f'\nrrandiops={rrandiops}, determining wbps...')
+wbps = run_fio(testfile, args.duration, 'write',
+               1, args.seqio_block_mb * (2 ** 20), args.numjobs)
+info(f'\nwbps={wbps}, determining wseqiops...')
+wseqiops = round(run_fio(testfile, args.duration, 'write',
+                         args.seq_depth, 4096, args.numjobs) / 4096)
+info(f'\nwseqiops={wseqiops}, determining wrandiops...')
+wrandiops = round(run_fio(testfile, args.duration, 'randwrite',
+                          args.rand_depth, 4096, args.numjobs) / 4096)
+info(f'\nwrandiops={wrandiops}')
+restore_elevator_nomerges()
+atexit.unregister(restore_elevator_nomerges)
+info('')
+
+print(f'{devno} rbps={rbps} rseqiops={rseqiops} rrandiops={rrandiops} '
+      f'wbps={wbps} wseqiops={wseqiops} wrandiops={wrandiops}')
diff --git a/tools/cgroup/iocost_monitor.py b/tools/cgroup/iocost_monitor.py
new file mode 100644
index 0000000..f79b235
--- /dev/null
+++ b/tools/cgroup/iocost_monitor.py
@@ -0,0 +1,277 @@
+#!/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')
+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_()
+NR_USAGE_SLOTS  = prog['NR_USAGE_SLOTS'].value_()
+HWEIGHT_WHOLE   = prog['HWEIGHT_WHOLE'].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 blkcg_name(blkcg):
+        return blkcg.css.cgroup.kn.name.string_().decode('utf-8')
+
+    def walk(self, blkcg, q_id, parent_path):
+        if not self.include_dying and \
+           not (blkcg.css.flags.value_() & prog['CSS_ONLINE'].value_()):
+            return
+
+        name = BlkgIterator.blkcg_name(blkcg)
+        path = parent_path + '/' + name if parent_path else name
+        blkg = drgn.Object(prog, 'struct blkcg_gq',
+                           address=radix_tree_lookup(blkcg.blkg_tree, q_id))
+        if not blkg.address_:
+            return
+
+        self.blkgs.append((path if path else '/', blkg))
+
+        for c in list_for_each_entry('struct blkcg',
+                                     blkcg.css.children.address_of_(), 'css.sibling'):
+            self.walk(c, q_id, path)
+
+    def __init__(self, root_blkcg, q_id, include_dying=False):
+        self.include_dying = include_dying
+        self.blkgs = []
+        self.walk(root_blkcg, q_id, '')
+
+    def __iter__(self):
+        return iter(self.blkgs)
+
+class IocStat:
+    def __init__(self, ioc):
+        global autop_names
+
+        self.enabled = ioc.enabled.value_()
+        self.running = ioc.running.value_() == IOC_RUNNING
+        self.period_ms = ioc.period_us.value_() / 1_000
+        self.period_at = ioc.period_at.value_() / 1_000_000
+        self.vperiod_at = ioc.period_at_vtime.value_() / VTIME_PER_SEC
+        self.vrate_pct = ioc.vtime_rate.counter.value_() * 100 / VTIME_PER_USEC
+        self.busy_level = ioc.busy_level.value_()
+        self.autop_idx = ioc.autop_idx.value_()
+        self.user_cost_model = ioc.user_cost_model.value_()
+        self.user_qos_params = ioc.user_qos_params.value_()
+
+        if self.autop_idx in autop_names:
+            self.autop_name = autop_names[self.autop_idx]
+        else:
+            self.autop_name = '?'
+
+    def dict(self, now):
+        return { 'device'               : devname,
+                 'timestamp'            : str(now),
+                 'enabled'              : str(int(self.enabled)),
+                 'running'              : str(int(self.running)),
+                 'period_ms'            : str(self.period_ms),
+                 'period_at'            : str(self.period_at),
+                 'period_vtime_at'      : str(self.vperiod_at),
+                 'busy_level'           : str(self.busy_level),
+                 'vrate_pct'            : str(self.vrate_pct), }
+
+    def table_preamble_str(self):
+        state = ('RUN' if self.running else 'IDLE') if self.enabled else 'OFF'
+        output = f'{devname} {state:4} ' \
+                 f'per={self.period_ms}ms ' \
+                 f'cur_per={self.period_at:.3f}:v{self.vperiod_at:.3f} ' \
+                 f'busy={self.busy_level:+3} ' \
+                 f'vrate={self.vrate_pct:6.2f}% ' \
+                 f'params={self.autop_name}'
+        if self.user_cost_model or self.user_qos_params:
+            output += f'({"C" if self.user_cost_model else ""}{"Q" if self.user_qos_params else ""})'
+        return output
+
+    def table_header_str(self):
+        return f'{"":25} active {"weight":>9} {"hweight%":>13} {"inflt%":>6} ' \
+               f'{"dbt":>3} {"delay":>6} {"usages%"}'
+
+class IocgStat:
+    def __init__(self, iocg):
+        ioc = iocg.ioc
+        blkg = iocg.pd.blkg
+
+        self.is_active = not list_empty(iocg.active_list.address_of_())
+        self.weight = iocg.weight.value_()
+        self.active = iocg.active.value_()
+        self.inuse = iocg.inuse.value_()
+        self.hwa_pct = iocg.hweight_active.value_() * 100 / HWEIGHT_WHOLE
+        self.hwi_pct = iocg.hweight_inuse.value_() * 100 / HWEIGHT_WHOLE
+        self.address = iocg.value_()
+
+        vdone = iocg.done_vtime.counter.value_()
+        vtime = iocg.vtime.counter.value_()
+        vrate = ioc.vtime_rate.counter.value_()
+        period_vtime = ioc.period_us.value_() * vrate
+        if period_vtime:
+            self.inflight_pct = (vtime - vdone) * 100 / period_vtime
+        else:
+            self.inflight_pct = 0
+
+        self.debt_ms = iocg.abs_vdebt.counter.value_() / VTIME_PER_USEC / 1000
+        self.use_delay = blkg.use_delay.counter.value_()
+        self.delay_ms = blkg.delay_nsec.counter.value_() / 1_000_000
+
+        usage_idx = iocg.usage_idx.value_()
+        self.usages = []
+        self.usage = 0
+        for i in range(NR_USAGE_SLOTS):
+            usage = iocg.usages[(usage_idx + i) % NR_USAGE_SLOTS].value_()
+            upct = usage * 100 / HWEIGHT_WHOLE
+            self.usages.append(upct)
+            self.usage = max(self.usage, upct)
+
+    def dict(self, now, path):
+        out = { 'cgroup'                : path,
+                'timestamp'             : str(now),
+                'is_active'             : str(int(self.is_active)),
+                'weight'                : str(self.weight),
+                'weight_active'         : str(self.active),
+                'weight_inuse'          : str(self.inuse),
+                'hweight_active_pct'    : str(self.hwa_pct),
+                'hweight_inuse_pct'     : str(self.hwi_pct),
+                'inflight_pct'          : str(self.inflight_pct),
+                'debt_ms'               : str(self.debt_ms),
+                'use_delay'             : str(self.use_delay),
+                'delay_ms'              : str(self.delay_ms),
+                'usage_pct'             : str(self.usage),
+                'address'               : str(hex(self.address)) }
+        for i in range(len(self.usages)):
+            out[f'usage_pct_{i}'] = str(self.usages[i])
+        return out
+
+    def table_row_str(self, path):
+        out = f'{path[-28:]:28} ' \
+              f'{"*" if self.is_active else " "} ' \
+              f'{self.inuse:5}/{self.active:5} ' \
+              f'{self.hwi_pct:6.2f}/{self.hwa_pct:6.2f} ' \
+              f'{self.inflight_pct:6.2f} ' \
+              f'{min(math.ceil(self.debt_ms), 999):3} ' \
+              f'{min(self.use_delay, 99):2}*'\
+              f'{min(math.ceil(self.delay_ms), 999):03} '
+        for u in self.usages:
+            out += f'{min(round(u), 999):03d}:'
+        out = out.rstrip(':')
+        return out
+
+# handle args
+table_fmt = not args.json
+interval = args.interval
+devname = args.devname
+
+if args.json:
+    table_fmt = False
+
+re_str = None
+if args.cgroup:
+    for r in args.cgroup:
+        if re_str is None:
+            re_str = r
+        else:
+            re_str += '|' + r
+
+filter_re = re.compile(re_str) if re_str else None
+
+# Locate the roots
+q_id = None
+root_iocg = None
+ioc = None
+
+for i, ptr in radix_tree_for_each(blkcg_root.blkg_tree):
+    blkg = drgn.Object(prog, 'struct blkcg_gq', address=ptr)
+    try:
+        if devname == blkg.q.kobj.parent.name.string_().decode('utf-8'):
+            q_id = blkg.q.id.value_()
+            if blkg.pd[plid]:
+                root_iocg = container_of(blkg.pd[plid], 'struct ioc_gq', 'pd')
+                ioc = root_iocg.ioc
+            break
+    except:
+        pass
+
+if ioc is None:
+    err(f'Could not find ioc for {devname}');
+
+# Keep printing
+while True:
+    now = time.time()
+    iocstat = IocStat(ioc)
+    output = ''
+
+    if table_fmt:
+        output += '\n' + iocstat.table_preamble_str()
+        output += '\n' + iocstat.table_header_str()
+    else:
+        output += json.dumps(iocstat.dict(now))
+
+    for path, blkg in BlkgIterator(blkcg_root, q_id):
+        if filter_re and not filter_re.match(path):
+            continue
+        if not blkg.pd[plid]:
+            continue
+
+        iocg = container_of(blkg.pd[plid], 'struct ioc_gq', 'pd')
+        iocg_stat = IocgStat(iocg)
+
+        if not filter_re and not iocg_stat.is_active:
+            continue
+
+        if table_fmt:
+            output += '\n' + iocg_stat.table_row_str(path)
+        else:
+            output += '\n' + json.dumps(iocg_stat.dict(now, path))
+
+    print(output)
+    sys.stdout.flush()
+    time.sleep(interval)