linux/Documentation/RCU/trace.txt
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   1CONFIG_RCU_TRACE debugfs Files and Formats
   2
   3
   4The rcutree and rcutiny implementations of RCU provide debugfs trace
   5output that summarizes counters and state.  This information is useful for
   6debugging RCU itself, and can sometimes also help to debug abuses of RCU.
   7The following sections describe the debugfs files and formats, first
   8for rcutree and next for rcutiny.
   9
  10
  11CONFIG_TREE_RCU and CONFIG_TREE_PREEMPT_RCU debugfs Files and Formats
  12
  13These implementations of RCU provides several debugfs files under the
  14top-level directory "rcu":
  15
  16rcu/rcudata:
  17        Displays fields in struct rcu_data.
  18rcu/rcudata.csv:
  19        Comma-separated values spreadsheet version of rcudata.
  20rcu/rcugp:
  21        Displays grace-period counters.
  22rcu/rcuhier:
  23        Displays the struct rcu_node hierarchy.
  24rcu/rcu_pending:
  25        Displays counts of the reasons rcu_pending() decided that RCU had
  26        work to do.
  27rcu/rcutorture:
  28        Displays rcutorture test progress.
  29rcu/rcuboost:
  30        Displays RCU boosting statistics.  Only present if
  31        CONFIG_RCU_BOOST=y.
  32
  33The output of "cat rcu/rcudata" looks as follows:
  34
  35rcu_sched:
  36  0 c=20972 g=20973 pq=1 pgp=20973 qp=0 dt=545/1/0 df=50 of=0 ql=163 qs=NRW. kt=0/W/0 ktl=ebc3 b=10 ci=153737 co=0 ca=0
  37  1 c=20972 g=20973 pq=1 pgp=20973 qp=0 dt=967/1/0 df=58 of=0 ql=634 qs=NRW. kt=0/W/1 ktl=58c b=10 ci=191037 co=0 ca=0
  38  2 c=20972 g=20973 pq=1 pgp=20973 qp=0 dt=1081/1/0 df=175 of=0 ql=74 qs=N.W. kt=0/W/2 ktl=da94 b=10 ci=75991 co=0 ca=0
  39  3 c=20942 g=20943 pq=1 pgp=20942 qp=1 dt=1846/0/0 df=404 of=0 ql=0 qs=.... kt=0/W/3 ktl=d1cd b=10 ci=72261 co=0 ca=0
  40  4 c=20972 g=20973 pq=1 pgp=20973 qp=0 dt=369/1/0 df=83 of=0 ql=48 qs=N.W. kt=0/W/4 ktl=e0e7 b=10 ci=128365 co=0 ca=0
  41  5 c=20972 g=20973 pq=1 pgp=20973 qp=0 dt=381/1/0 df=64 of=0 ql=169 qs=NRW. kt=0/W/5 ktl=fb2f b=10 ci=164360 co=0 ca=0
  42  6 c=20972 g=20973 pq=1 pgp=20973 qp=0 dt=1037/1/0 df=183 of=0 ql=62 qs=N.W. kt=0/W/6 ktl=d2ad b=10 ci=65663 co=0 ca=0
  43  7 c=20897 g=20897 pq=1 pgp=20896 qp=0 dt=1572/0/0 df=382 of=0 ql=0 qs=.... kt=0/W/7 ktl=cf15 b=10 ci=75006 co=0 ca=0
  44rcu_bh:
  45  0 c=1480 g=1480 pq=1 pgp=1480 qp=0 dt=545/1/0 df=6 of=0 ql=0 qs=.... kt=0/W/0 ktl=ebc3 b=10 ci=0 co=0 ca=0
  46  1 c=1480 g=1480 pq=1 pgp=1480 qp=0 dt=967/1/0 df=3 of=0 ql=0 qs=.... kt=0/W/1 ktl=58c b=10 ci=151 co=0 ca=0
  47  2 c=1480 g=1480 pq=1 pgp=1480 qp=0 dt=1081/1/0 df=6 of=0 ql=0 qs=.... kt=0/W/2 ktl=da94 b=10 ci=0 co=0 ca=0
  48  3 c=1480 g=1480 pq=1 pgp=1480 qp=0 dt=1846/0/0 df=8 of=0 ql=0 qs=.... kt=0/W/3 ktl=d1cd b=10 ci=0 co=0 ca=0
  49  4 c=1480 g=1480 pq=1 pgp=1480 qp=0 dt=369/1/0 df=6 of=0 ql=0 qs=.... kt=0/W/4 ktl=e0e7 b=10 ci=0 co=0 ca=0
  50  5 c=1480 g=1480 pq=1 pgp=1480 qp=0 dt=381/1/0 df=4 of=0 ql=0 qs=.... kt=0/W/5 ktl=fb2f b=10 ci=0 co=0 ca=0
  51  6 c=1480 g=1480 pq=1 pgp=1480 qp=0 dt=1037/1/0 df=6 of=0 ql=0 qs=.... kt=0/W/6 ktl=d2ad b=10 ci=0 co=0 ca=0
  52  7 c=1474 g=1474 pq=1 pgp=1473 qp=0 dt=1572/0/0 df=8 of=0 ql=0 qs=.... kt=0/W/7 ktl=cf15 b=10 ci=0 co=0 ca=0
  53
  54The first section lists the rcu_data structures for rcu_sched, the second
  55for rcu_bh.  Note that CONFIG_TREE_PREEMPT_RCU kernels will have an
  56additional section for rcu_preempt.  Each section has one line per CPU,
  57or eight for this 8-CPU system.  The fields are as follows:
  58
  59o       The number at the beginning of each line is the CPU number.
  60        CPUs numbers followed by an exclamation mark are offline,
  61        but have been online at least once since boot.  There will be
  62        no output for CPUs that have never been online, which can be
  63        a good thing in the surprisingly common case where NR_CPUS is
  64        substantially larger than the number of actual CPUs.
  65
  66o       "c" is the count of grace periods that this CPU believes have
  67        completed.  Offlined CPUs and CPUs in dynticks idle mode may
  68        lag quite a ways behind, for example, CPU 6 under "rcu_sched"
  69        above, which has been offline through not quite 40,000 RCU grace
  70        periods.  It is not unusual to see CPUs lagging by thousands of
  71        grace periods.
  72
  73o       "g" is the count of grace periods that this CPU believes have
  74        started.  Again, offlined CPUs and CPUs in dynticks idle mode
  75        may lag behind.  If the "c" and "g" values are equal, this CPU
  76        has already reported a quiescent state for the last RCU grace
  77        period that it is aware of, otherwise, the CPU believes that it
  78        owes RCU a quiescent state.
  79
  80o       "pq" indicates that this CPU has passed through a quiescent state
  81        for the current grace period.  It is possible for "pq" to be
  82        "1" and "c" different than "g", which indicates that although
  83        the CPU has passed through a quiescent state, either (1) this
  84        CPU has not yet reported that fact, (2) some other CPU has not
  85        yet reported for this grace period, or (3) both.
  86
  87o       "pgp" indicates which grace period the last-observed quiescent
  88        state for this CPU corresponds to.  This is important for handling
  89        the race between CPU 0 reporting an extended dynticks-idle
  90        quiescent state for CPU 1 and CPU 1 suddenly waking up and
  91        reporting its own quiescent state.  If CPU 1 was the last CPU
  92        for the current grace period, then the CPU that loses this race
  93        will attempt to incorrectly mark CPU 1 as having checked in for
  94        the next grace period!
  95
  96o       "qp" indicates that RCU still expects a quiescent state from
  97        this CPU.  Offlined CPUs and CPUs in dyntick idle mode might
  98        well have qp=1, which is OK: RCU is still ignoring them.
  99
 100o       "dt" is the current value of the dyntick counter that is incremented
 101        when entering or leaving dynticks idle state, either by the
 102        scheduler or by irq.  This number is even if the CPU is in
 103        dyntick idle mode and odd otherwise.  The number after the first
 104        "/" is the interrupt nesting depth when in dyntick-idle state,
 105        or one greater than the interrupt-nesting depth otherwise.
 106        The number after the second "/" is the NMI nesting depth.
 107
 108o       "df" is the number of times that some other CPU has forced a
 109        quiescent state on behalf of this CPU due to this CPU being in
 110        dynticks-idle state.
 111
 112o       "of" is the number of times that some other CPU has forced a
 113        quiescent state on behalf of this CPU due to this CPU being
 114        offline.  In a perfect world, this might never happen, but it
 115        turns out that offlining and onlining a CPU can take several grace
 116        periods, and so there is likely to be an extended period of time
 117        when RCU believes that the CPU is online when it really is not.
 118        Please note that erring in the other direction (RCU believing a
 119        CPU is offline when it is really alive and kicking) is a fatal
 120        error, so it makes sense to err conservatively.
 121
 122o       "ql" is the number of RCU callbacks currently residing on
 123        this CPU.  This is the total number of callbacks, regardless
 124        of what state they are in (new, waiting for grace period to
 125        start, waiting for grace period to end, ready to invoke).
 126
 127o       "qs" gives an indication of the state of the callback queue
 128        with four characters:
 129
 130        "N"     Indicates that there are callbacks queued that are not
 131                ready to be handled by the next grace period, and thus
 132                will be handled by the grace period following the next
 133                one.
 134
 135        "R"     Indicates that there are callbacks queued that are
 136                ready to be handled by the next grace period.
 137
 138        "W"     Indicates that there are callbacks queued that are
 139                waiting on the current grace period.
 140
 141        "D"     Indicates that there are callbacks queued that have
 142                already been handled by a prior grace period, and are
 143                thus waiting to be invoked.  Note that callbacks in
 144                the process of being invoked are not counted here.
 145                Callbacks in the process of being invoked are those
 146                that have been removed from the rcu_data structures
 147                queues by rcu_do_batch(), but which have not yet been
 148                invoked.
 149
 150        If there are no callbacks in a given one of the above states,
 151        the corresponding character is replaced by ".".
 152
 153o       "kt" is the per-CPU kernel-thread state.  The digit preceding
 154        the first slash is zero if there is no work pending and 1
 155        otherwise.  The character between the first pair of slashes is
 156        as follows:
 157
 158        "S"     The kernel thread is stopped, in other words, all
 159                CPUs corresponding to this rcu_node structure are
 160                offline.
 161
 162        "R"     The kernel thread is running.
 163
 164        "W"     The kernel thread is waiting because there is no work
 165                for it to do.
 166
 167        "O"     The kernel thread is waiting because it has been
 168                forced off of its designated CPU or because its
 169                ->cpus_allowed mask permits it to run on other than
 170                its designated CPU.
 171
 172        "Y"     The kernel thread is yielding to avoid hogging CPU.
 173
 174        "?"     Unknown value, indicates a bug.
 175
 176        The number after the final slash is the CPU that the kthread
 177        is actually running on.
 178
 179        This field is displayed only for CONFIG_RCU_BOOST kernels.
 180
 181o       "ktl" is the low-order 16 bits (in hexadecimal) of the count of
 182        the number of times that this CPU's per-CPU kthread has gone
 183        through its loop servicing invoke_rcu_cpu_kthread() requests.
 184
 185        This field is displayed only for CONFIG_RCU_BOOST kernels.
 186
 187o       "b" is the batch limit for this CPU.  If more than this number
 188        of RCU callbacks is ready to invoke, then the remainder will
 189        be deferred.
 190
 191o       "ci" is the number of RCU callbacks that have been invoked for
 192        this CPU.  Note that ci+ql is the number of callbacks that have
 193        been registered in absence of CPU-hotplug activity.
 194
 195o       "co" is the number of RCU callbacks that have been orphaned due to
 196        this CPU going offline.  These orphaned callbacks have been moved
 197        to an arbitrarily chosen online CPU.
 198
 199o       "ca" is the number of RCU callbacks that have been adopted due to
 200        other CPUs going offline.  Note that ci+co-ca+ql is the number of
 201        RCU callbacks registered on this CPU.
 202
 203There is also an rcu/rcudata.csv file with the same information in
 204comma-separated-variable spreadsheet format.
 205
 206
 207The output of "cat rcu/rcugp" looks as follows:
 208
 209rcu_sched: completed=33062  gpnum=33063
 210rcu_bh: completed=464  gpnum=464
 211
 212Again, this output is for both "rcu_sched" and "rcu_bh".  Note that
 213kernels built with CONFIG_TREE_PREEMPT_RCU will have an additional
 214"rcu_preempt" line.  The fields are taken from the rcu_state structure,
 215and are as follows:
 216
 217o       "completed" is the number of grace periods that have completed.
 218        It is comparable to the "c" field from rcu/rcudata in that a
 219        CPU whose "c" field matches the value of "completed" is aware
 220        that the corresponding RCU grace period has completed.
 221
 222o       "gpnum" is the number of grace periods that have started.  It is
 223        comparable to the "g" field from rcu/rcudata in that a CPU
 224        whose "g" field matches the value of "gpnum" is aware that the
 225        corresponding RCU grace period has started.
 226
 227        If these two fields are equal (as they are for "rcu_bh" above),
 228        then there is no grace period in progress, in other words, RCU
 229        is idle.  On the other hand, if the two fields differ (as they
 230        do for "rcu_sched" above), then an RCU grace period is in progress.
 231
 232
 233The output of "cat rcu/rcuhier" looks as follows, with very long lines:
 234
 235c=6902 g=6903 s=2 jfq=3 j=72c7 nfqs=13142/nfqsng=0(13142) fqlh=6
 2361/1 ..>. 0:127 ^0
 2373/3 ..>. 0:35 ^0    0/0 ..>. 36:71 ^1    0/0 ..>. 72:107 ^2    0/0 ..>. 108:127 ^3
 2383/3f ..>. 0:5 ^0    2/3 ..>. 6:11 ^1    0/0 ..>. 12:17 ^2    0/0 ..>. 18:23 ^3    0/0 ..>. 24:29 ^4    0/0 ..>. 30:35 ^5    0/0 ..>. 36:41 ^0    0/0 ..>. 42:47 ^1    0/0 ..>. 48:53 ^2    0/0 ..>. 54:59 ^3    0/0 ..>. 60:65 ^4    0/0 ..>. 66:71 ^5    0/0 ..>. 72:77 ^0    0/0 ..>. 78:83 ^1    0/0 ..>. 84:89 ^2    0/0 ..>. 90:95 ^3    0/0 ..>. 96:101 ^4    0/0 ..>. 102:107 ^5    0/0 ..>. 108:113 ^0    0/0 ..>. 114:119 ^1    0/0 ..>. 120:125 ^2    0/0 ..>. 126:127 ^3
 239rcu_bh:
 240c=-226 g=-226 s=1 jfq=-5701 j=72c7 nfqs=88/nfqsng=0(88) fqlh=0
 2410/1 ..>. 0:127 ^0
 2420/3 ..>. 0:35 ^0    0/0 ..>. 36:71 ^1    0/0 ..>. 72:107 ^2    0/0 ..>. 108:127 ^3
 2430/3f ..>. 0:5 ^0    0/3 ..>. 6:11 ^1    0/0 ..>. 12:17 ^2    0/0 ..>. 18:23 ^3    0/0 ..>. 24:29 ^4    0/0 ..>. 30:35 ^5    0/0 ..>. 36:41 ^0    0/0 ..>. 42:47 ^1    0/0 ..>. 48:53 ^2    0/0 ..>. 54:59 ^3    0/0 ..>. 60:65 ^4    0/0 ..>. 66:71 ^5    0/0 ..>. 72:77 ^0    0/0 ..>. 78:83 ^1    0/0 ..>. 84:89 ^2    0/0 ..>. 90:95 ^3    0/0 ..>. 96:101 ^4    0/0 ..>. 102:107 ^5    0/0 ..>. 108:113 ^0    0/0 ..>. 114:119 ^1    0/0 ..>. 120:125 ^2    0/0 ..>. 126:127 ^3
 244
 245This is once again split into "rcu_sched" and "rcu_bh" portions,
 246and CONFIG_TREE_PREEMPT_RCU kernels will again have an additional
 247"rcu_preempt" section.  The fields are as follows:
 248
 249o       "c" is exactly the same as "completed" under rcu/rcugp.
 250
 251o       "g" is exactly the same as "gpnum" under rcu/rcugp.
 252
 253o       "s" is the "signaled" state that drives force_quiescent_state()'s
 254        state machine.
 255
 256o       "jfq" is the number of jiffies remaining for this grace period
 257        before force_quiescent_state() is invoked to help push things
 258        along.  Note that CPUs in dyntick-idle mode throughout the grace
 259        period will not report on their own, but rather must be check by
 260        some other CPU via force_quiescent_state().
 261
 262o       "j" is the low-order four hex digits of the jiffies counter.
 263        Yes, Paul did run into a number of problems that turned out to
 264        be due to the jiffies counter no longer counting.  Why do you ask?
 265
 266o       "nfqs" is the number of calls to force_quiescent_state() since
 267        boot.
 268
 269o       "nfqsng" is the number of useless calls to force_quiescent_state(),
 270        where there wasn't actually a grace period active.  This can
 271        happen due to races.  The number in parentheses is the difference
 272        between "nfqs" and "nfqsng", or the number of times that
 273        force_quiescent_state() actually did some real work.
 274
 275o       "fqlh" is the number of calls to force_quiescent_state() that
 276        exited immediately (without even being counted in nfqs above)
 277        due to contention on ->fqslock.
 278
 279o       Each element of the form "1/1 0:127 ^0" represents one struct
 280        rcu_node.  Each line represents one level of the hierarchy, from
 281        root to leaves.  It is best to think of the rcu_data structures
 282        as forming yet another level after the leaves.  Note that there
 283        might be either one, two, or three levels of rcu_node structures,
 284        depending on the relationship between CONFIG_RCU_FANOUT and
 285        CONFIG_NR_CPUS.
 286
 287        o       The numbers separated by the "/" are the qsmask followed
 288                by the qsmaskinit.  The qsmask will have one bit
 289                set for each entity in the next lower level that
 290                has not yet checked in for the current grace period.
 291                The qsmaskinit will have one bit for each entity that is
 292                currently expected to check in during each grace period.
 293                The value of qsmaskinit is assigned to that of qsmask
 294                at the beginning of each grace period.
 295
 296                For example, for "rcu_sched", the qsmask of the first
 297                entry of the lowest level is 0x14, meaning that we
 298                are still waiting for CPUs 2 and 4 to check in for the
 299                current grace period.
 300
 301        o       The characters separated by the ">" indicate the state
 302                of the blocked-tasks lists.  A "G" preceding the ">"
 303                indicates that at least one task blocked in an RCU
 304                read-side critical section blocks the current grace
 305                period, while a "E" preceding the ">" indicates that
 306                at least one task blocked in an RCU read-side critical
 307                section blocks the current expedited grace period.
 308                A "T" character following the ">" indicates that at
 309                least one task is blocked within an RCU read-side
 310                critical section, regardless of whether any current
 311                grace period (expedited or normal) is inconvenienced.
 312                A "." character appears if the corresponding condition
 313                does not hold, so that "..>." indicates that no tasks
 314                are blocked.  In contrast, "GE>T" indicates maximal
 315                inconvenience from blocked tasks.
 316
 317        o       The numbers separated by the ":" are the range of CPUs
 318                served by this struct rcu_node.  This can be helpful
 319                in working out how the hierarchy is wired together.
 320
 321                For example, the first entry at the lowest level shows
 322                "0:5", indicating that it covers CPUs 0 through 5.
 323
 324        o       The number after the "^" indicates the bit in the
 325                next higher level rcu_node structure that this
 326                rcu_node structure corresponds to.
 327
 328                For example, the first entry at the lowest level shows
 329                "^0", indicating that it corresponds to bit zero in
 330                the first entry at the middle level.
 331
 332
 333The output of "cat rcu/rcu_pending" looks as follows:
 334
 335rcu_sched:
 336  0 np=255892 qsp=53936 rpq=85 cbr=0 cng=14417 gpc=10033 gps=24320 nf=6445 nn=146741
 337  1 np=261224 qsp=54638 rpq=33 cbr=0 cng=25723 gpc=16310 gps=2849 nf=5912 nn=155792
 338  2 np=237496 qsp=49664 rpq=23 cbr=0 cng=2762 gpc=45478 gps=1762 nf=1201 nn=136629
 339  3 np=236249 qsp=48766 rpq=98 cbr=0 cng=286 gpc=48049 gps=1218 nf=207 nn=137723
 340  4 np=221310 qsp=46850 rpq=7 cbr=0 cng=26 gpc=43161 gps=4634 nf=3529 nn=123110
 341  5 np=237332 qsp=48449 rpq=9 cbr=0 cng=54 gpc=47920 gps=3252 nf=201 nn=137456
 342  6 np=219995 qsp=46718 rpq=12 cbr=0 cng=50 gpc=42098 gps=6093 nf=4202 nn=120834
 343  7 np=249893 qsp=49390 rpq=42 cbr=0 cng=72 gpc=38400 gps=17102 nf=41 nn=144888
 344rcu_bh:
 345  0 np=146741 qsp=1419 rpq=6 cbr=0 cng=6 gpc=0 gps=0 nf=2 nn=145314
 346  1 np=155792 qsp=12597 rpq=3 cbr=0 cng=0 gpc=4 gps=8 nf=3 nn=143180
 347  2 np=136629 qsp=18680 rpq=1 cbr=0 cng=0 gpc=7 gps=6 nf=0 nn=117936
 348  3 np=137723 qsp=2843 rpq=0 cbr=0 cng=0 gpc=10 gps=7 nf=0 nn=134863
 349  4 np=123110 qsp=12433 rpq=0 cbr=0 cng=0 gpc=4 gps=2 nf=0 nn=110671
 350  5 np=137456 qsp=4210 rpq=1 cbr=0 cng=0 gpc=6 gps=5 nf=0 nn=133235
 351  6 np=120834 qsp=9902 rpq=2 cbr=0 cng=0 gpc=6 gps=3 nf=2 nn=110921
 352  7 np=144888 qsp=26336 rpq=0 cbr=0 cng=0 gpc=8 gps=2 nf=0 nn=118542
 353
 354As always, this is once again split into "rcu_sched" and "rcu_bh"
 355portions, with CONFIG_TREE_PREEMPT_RCU kernels having an additional
 356"rcu_preempt" section.  The fields are as follows:
 357
 358o       "np" is the number of times that __rcu_pending() has been invoked
 359        for the corresponding flavor of RCU.
 360
 361o       "qsp" is the number of times that the RCU was waiting for a
 362        quiescent state from this CPU.
 363
 364o       "rpq" is the number of times that the CPU had passed through
 365        a quiescent state, but not yet reported it to RCU.
 366
 367o       "cbr" is the number of times that this CPU had RCU callbacks
 368        that had passed through a grace period, and were thus ready
 369        to be invoked.
 370
 371o       "cng" is the number of times that this CPU needed another
 372        grace period while RCU was idle.
 373
 374o       "gpc" is the number of times that an old grace period had
 375        completed, but this CPU was not yet aware of it.
 376
 377o       "gps" is the number of times that a new grace period had started,
 378        but this CPU was not yet aware of it.
 379
 380o       "nf" is the number of times that this CPU suspected that the
 381        current grace period had run for too long, and thus needed to
 382        be forced.
 275o       "56xt#L384" i3="L284" class=Pame=e8"> ea>          ne" he output css=    he chne" nam="Ls on IPIimes that this CPU had RCU callbacks
 2quiesly="L298"; abov" at at least one task blocked in an RCU
 304       do for wequiesly=do      fore nuname="Lme="L382"> 382        be forced.
&quon/u na"L307et_st       ne" he output iuot;rpq" ii78"> 3"L298";g that it corresponds to bit zero in
 304       do"liname="L290"> ="L359"that __rcu_pending() has been invoked
        is actually running on.
 190
 371o       "cng" is the nuber the jiAlern, regardless of whether any current
="line"nnme="L37o   of t gi    ="L26er a grace period, and were thus ready
>        whoto &qu="line" name="L3o   of ther      " nameTher level rcu_node structure that this
   aluructuabovuot; is the n7        is actually running on.
 295
 376
 207t a ureoutput of "cat rcu/rcu_pending" looks as follows:
 198
o : 61r=0 cng=0 gpc=6 gps=5 nf=0 nn=133235
 331
 2he fi> 371o     " ct a ure texaquot; is the number o" class="line" name="L331"> 331
,/a>        (texambove), thenuot;rcu_sched" and "rcu_bh"
 2he fi> 371o    _sched" and "rcu_bh"
  icatinf " name="_sched" and "rcu_bh"
 357
 208
 207"listoutput of "cat rcu/rcu_pending" looks as follows:
 190
 295
 2> 330" class="line" name="L295"> 295
 208
 222o  rated "line" name="L359"> 35two-0"> " class="line" name="L208"> 208
 330 314o    mbene" namewitho 328          quot;0" class="line" name="L208"> 208
 368o    59""      quot;0=5&quor=0 cng=0 gpc=7 gps=6 nf=0 nn=117936
        is actually running on.
 323
 323
      section.  The fields are as follows:
 226
 308&clascold, so that " nameame="line  that        " class="line" name="L226"> 226
"L177"> 77">  name="L3ame="L359"> 355&quoL372"" class="line" name="L226"> 226
 356<" class="line" name="L226"> 226
 190
 308&clascold, so that "line"me="L302"> 30e  ame=ineveo the" class="line" name="L190"> 190
    )name="L381"> 3esents one level of the hierarchy, from
 334
 308&clascold, so that "line"me="L302"> 30e  ame=ineveo the" class="line" name="L190"> 190
                section blocks62"> 3 numberthe ts one level of the hierarchy, from
 357
 308&clascold, so that "line"me="L302"> 30e  ame=;g that it corresponds to bit zero in
 190
       ihroupl0 312< A "." cha" class="line" name="L190"> 190
 3 ts one level of the hierarchy, from
 323
 222 323
       m="L3ame="L359"> 35ame="L326"> 326  name="L3         section.  The fields are as follows:
 357
 308&etions, =fht leu318 323
 35tog"ame="L326"> 326ael after the leaves.  Note that there
 331
 308&etions, =fht leu318"L177"> ts one level of the hierarchy, from
 353
 308&etions, =fht leu318e numberbecause " name=" &qu="L3" class="line" name="L353"> 353
 226
 308&etions, =fht leu318yt;rc> 35togavoid3">gg> 355&q  rcu_node structure corresponds to.
 208
 353
 361o4      &qu4t;qsp" is the numbe4 of t4mes that the RCU wasntbether any current
 333T4a href="D4cumentation/RCU/trace.tx4#L36446quot; state that drnebether any current
 271 4      &qu4t;rpq" is the numbe4 of t4nger counting.U/trace.txt#L308" id="L308" class="line" name="L308"> 308 4      a q4iescent state, but not y4t rep4 id="L266" class="line" name="L266"> 266o4a href="D4cumentation/RCU/trace.tx4#L3674alls to force_quiescenbether any current
 266o4aht leu318t;cbr" is the numbe4 of t4ace.txt#L268" "Docu4entation/RCU/trace.txt#L433" .e.txatioxt#L445"aefL43266" class="line" name="L266"> 266o4a 4ref="Do had passed through a gr4ce pe4iod, and were thus CU/trace.on/RC.tx4entU/trace.tx i4=a "Docu4entation/RCU/t266" class="line" name="L266"> 266o4aefi4 grace invoked.
 266o4a href="D4cumentation/RCU/trace.tx4#L3714 id="L371" class="line" name="L371"> 371o4      &qu4t;cng" is the numbe4 of t4mes that this CPU neiffies counter.
 266o4a href="D4cumentation/RCU/trace.tx4#L3744 id="L374" class="line" name="L374"> 374o4      &qu4t;gpc" is the numbe4 of t4mes that an old gracbtffies counter.
 374o4      a q4leted, but this CPU was 4ot ye4 aware of it.
 374o4  href="D4cumentation/RCU/trace.tx4#L3774ing counted inRCU/trace.txt#L291" id="txt#L443" ei4=bpush h i4/trace.t"L306&quoexambove), then7        is ac      &qu4t;gps" is the numbe4 of t4 266o4a 4ref="Dothis CPU was not yet awa4e of 4 id="L279" class="line" name="L279"> 279o4a href="D4cumentation/RCU/trace.tx4#L38047 class="line" name=Docu4entDocu3entaunty current
        is ac      be 4orced.
 285 4e="L275">4275o       "56x4#L3844levels of rcu_ntracenace.txt#L390"ce.txt#L446" i44"L326" class=T2  name="L3  output c4s=    he chne" nam="Ls o4 IPIi48i435L227" class=e="L30E"> 308&clascold,quiesly="4298"; abov" at at l4ast o48lls to force_quiescegtDocu3entaunty current
 308&clascold,q href="D4sly=do      fore nuname=4Lme="48ng counted inRCUis chis race.txt#L439,_ntrace/tracm chis race.f="Docu227" class=e="L30E"> 308&clascold,q     &qu4ut iuot;rpq" ii78">43"L294";g that it cotrace.txt#L291" id=",race.txt#Documentationt#L39wis"L326" class=T2  name="L3   4ref="Do"liname="L290"> ="L359"t4at __48id="L279" class="line" name="L279"> 279o4     is a4tually running on.
 279o4a 3ref="D4cu3entation/RCU/trace.tx4#L3914the current gr"Docalid="Lt#L359" it 291 4     &quo4;cng" is the nuber 4he ji49i452L227" class=e="L30R"> 308&etions, =>="line"n4me="L37o   of t gi  4 ="L249hex digits of the jnbether ataunty current
 283 4ine" name4"L3o   of ther      4 name4her level rcu_CU/ttical
 305 4ructuabov4ot; is the n7       4is ac4ually running " id="tt#L314ntarr"Doctes maximalfttationalid="Ltef="Docu4"L289" class="line" name="L289"> 289 4a 3ref="D4cu3entation/RCU/trace.tx4#L39649aware of it.
jtxt#wo
 289 4a href="D4cu3entation/RCU/trace.tx4#L3974 i39"L207" class="line" name="L207"> 207t a u4eoutput o4 "cat rcu/rcu_pendi4g&quo49es that a new gracenyether ataunty current
 207t a u4e 4ref="Docu3entation/RCU/trace.tx4#L39942 and 4 to chee.txt#L3f="Dtxt#on/RCioxt#L445L291" class="line" name="L291"> 291 4     is a4 even being counted in n4qs ab49id="L380" class="line" name="L380"> 380o5=0 cng=0 5pc=6 gps=5 nf=0 nn=133235
 380o5=1 cng=0 5pcng" is the nuber 5#L4025 the ">" i3="9,_e.g.CU/trat#L291" id="te38"Lace.txL291" class="line" name="L291"> 291 5ct a ure 5exaquot; is the number o5 clas50id="L333" class="line" name="L333"> 333T5L177">,/a5        (texambove), the5uot;r50id="L374" class="line" name="L374"> 374o5&qu   59"50"> 2he fi> 371o    5sched5quot; nal
 /207" class="line" name="L207"> 207t a u5   corres5/a>  icatinf " name="_sc5ed&qu50id="L266" class="line" name="L266"> 266o5tually ru5ning on.

 299 5a 4ref="D5cu4entation/RCU/trace.tx5#L4085 i4="Ltop-L329" directoryU/tr,trace 4re4entatdataquot;ch displaysU/trace."L329" class="line" n the       =iniorini5a 4ref="D5cu4entation/RCU/trace.tx5#L4095 i4="Lthis
<_ctrlblk, ocumentat_ctrlblk& i4rst
 266o5utput of 5quot;cat rcu/rcu_pending5quot;50e)
 291 5a 4ref="D5cu4entation/RCU/trace.tx5#L4115 i4="L311" na     =.... kt=W ntb36 reb36 rnb35 j=2f95 b5=300 _sched" and &q5ot;rc5_bh&quas follows:
 208
56 ros=1r=5 cng=0 gpc=7 gps=6 nf=0 5n=11751id="L333" class="line" name="L333"> 333T5 j=2f95 b5=300 _sched" and &q5ot;rc5_bh&qu 4rtion/RCU: qlen=2/tra=1097669 g197/p197/c197
 333T5 qu   59"5cng=0 gpc=7 gps=6 nf=0 n5=11795"GE>T"ttb=. btg=nontati184n/RCU/trace183 j=01f7trace27L346" class="line" name="L346"> 346 5a 4ref="D5cu4entation/RCU/trace.tx5#L4165tasks.
 347 5="line" n5ame="L28two-0"> 2> 330" 5lass=51 of the hierarchy,on/eDocu4erace.t41"L347" class="line" name="L347"> 347 5= 4ref="D5ot;rcu_preempt" sec5ion. 5The fi336" id="L qlen: L347" class="line" name="L347"> 347 5= 4ref="D5cu4entation/RCU/trace.tx5#L41951i4="Lthis
 347 5=tput of 5 "line" name="L359"> 35t5o-0">51id="L380" class="line" name="L380"> 380o5witho 3285/a>          quot;0" cla5s="li5e" namace.t"Lh"
 299 5o    59""5     quot;0=5&quor=0 cng50 gpc57 gps= 4rtion/RCUd.
 333T5 running 5n.
 333T5 j=2f95 b5cu4entation/RCU/trace.tx5#L4245 i42"Ltrace.txt#LBOOST 208
5d by the 5ame="L3ame=ou> 31g namot5 is t52i435L227" class=e="L30E"> 308&clascold5tion.  Th5 fields are as follows:
5a 4re52lls to force_quiescqlenether any current
 380o5a 4ref="D5cu4entation/RCU/trace.tx5#L4275nds to.
 299 5o 4ref="D5 nameame="line  that5     5 " class="linef="DoctracL436sref=cu4entat385" ice.tthis
<,.
 299 5o 4ref="D5="L359"> 355&quoL372"" c5ass="5ine" name="L22f="Docu3entatRCU/trat#L291" id="t id="oaceiwo368see"333" class="line" name="L333"> 333T5 tput of 5> 356<" class="line" nam5="L2252id="L380" class="line" name="L380"> 380o5a 4ref="D5cu4entation/RCU/trace.tx5#L43153s that this CPU susgaiting for a
 333T5 so that 5line"me="L302"> 30e 5ame=i5 id="L332" class="line" name="L332"> 332
5on-1 5  )name="L381"> 3esents 5ne le53hex digits of the jg197/p197/c197iting fdisplaysU/trat#L29-" id="tocumentditio="L299" class="line" name="L299"> 299 5el of the5hierarchy, from
 299 5e by the 5cu4entation/RCU/trace.tx5#L43553quot;GE>T&(m="t256)u4entation/Rpocu3entation/Rbef="Docum href="Doct#L291" id="t299" class="line" name="L299"> 299 5eion.  Th5line"me="L302"> 30e 5ame=i53l of the hierarion/RCU/traces389" i38"L 3re(alsd=m="t256)u4entation 4ref=" i4="L304st  curnd CON     uot;he fn(witho 3 numberthe ts o5e lev5l of the hieraation/Rbef="Docum href="Doct#L291" id="trace.txt#L403" i4="L303f cal="lines="lia texamservme="L292"5a 4ref="D5cu4entation/RCU/trace.tx5#L43853" class="line(quot;rcu_bhmxt#L256)"333" class="line" name="L333"> 333T5  4ref="D5line"me="L302"> 30e 5ame=;53id="L279" class="line" name="L279"> 279o5"listthe 5s one level of the hiera5chy, 5rom
 279o5a 4ref="D5cu4entation/RCU/trace.tx5#L441540ation/RCU/tr the jgaiting for f="Do436sref=cu4e trace.txt#LTRACE 333T5  me="L315"> 312< A "." 5ha" c54id="L332" class="line" name="L332"> 332
5e level o5 the hierarchy, from
L406" i4=5"L330" class="line" noffU/tr ts one level5a 4ref="D5cu4entation/RCU/trace.tx5#L44454er level rcu_not;
L40L311 i4="L325" class=rnp77      se5e="L359">535ame="L326"> 326 266o5        s5ction.  The fields are a5 foll5ws:
L40L311 i4="Lraush 77 266o5  4ref="D5cu4entation/RCU/trace.tx5#L44854" class="lineumentf="Docum 323
5g"ame5"L326"> 326ael after5the l54id="L380" class="line" name="L380"> 380o5of the hi5rarchy, from
L40L311 i4="Lrrace.txt#L439380" class="line" name="L380"> 380o5o me="L315cu4entation/RCU/trace.tx5#L45255the ">tion/xt#L37ce.txt#L440" i" ice.tentation/RCU/tt#L39wis"L326" class=T2  name="L35fht leu315"L177"> ts one level of 5he hi55id="L333" class="line" name="L333"> 333T5a 4ref="D5cu4entation/RCU/trace.tx5#L45455quot; state that drbtDocu3enta 4ref="Doace.txt#oxt#L445".txt#L359carritatiut.
 279o5fht leu315e numberbecause " name="5&qu="53" class="lineRCU/trace.txt#L291" id=","Docu4entatiU/tocu3enta 4ref=ocumentatoxt#L445279" class="line" name="L279"> 279o5e structu5e corresponds to.
 279o5e       s5cu4entation/RCU/trace.tx5#L457556 of the hierarionoxt#L445".txte.txt#L3on/RCU/trace.t"Docu4entation/RCU/t266" class="line" name="L266"> 266o5fht leu315yt;rc> 35togavoid3">gg> 555&q 5rcu_node structure cbegunocu3enta 4ref=ocumentatoxt#L445".txt#Lbugtrace.t"Docu4entati266" class="line" name="L266"> 266o5fht leu315cu4entation/RCU/trace.tx5#L45955ass="line" nan/RCU/trace.ocu3end  tocu3enta 4ref=ocumentatoxt#L445".txt03" i4="Ltrac266" class="line" name="L266"> 266o5f"ame5e
  name="L35a href="D5cumentation/RCU/trace.tx5#L3615 id="L361" class="line" name="L361"> 361o5      &qu5t;qsp" is the numbe5 of t5mes that the RCU wasntbether any currtotu4eent
 361o5 ht leu315scent state from this CP5.
 361o5  4ref="D5cumentation/RCU/trace.tx5#L3645 id="L364" class="line" name="L364"> 364o5      &qu5t;rpq" is the numbe5 of t5mes that the CPU hadnebether any current
 375 5      a q5iescent state, but not y5t rep56 task blocked ini40ort81oU/trace.txt#L440" i44"rd" and361" class="line" name="L361"> 361o5        s5cumentation/RCU/trace.tx5#L3675 id="L367" class="line" name="L367"> 367o5aht leu315t;cbr" is the numbe5 of t5mes that this CPU haenbether any current
 375 5 ht leu315 had passed through a gr5ce pe5iod, and were tini40ort81oU/trace.txt#L440" i44"rd" and361" class="line" name="L361"> 361o5 "ame5e invoked.
 380o5a href="D5cumentation/RCU/trace.tx5#L37157s that this CPU susiffies counter.
 266o5      &qu5t;cng" is the numbe5 of t57id="L332" class="line" name="L332"> 332
5      gra5e period while RCU was i5le.
<57hex digits of the jbtffies counter.
 332
5  4ref="D5cumentation/RCU/trace.tx5#L37457er level rcu_C"Documentot;
 190
5      &qu5t;gpc" is the numbe5 of t57i435L227" class=e="L30E"> 308&clascold5      a q5leted, but this CPU was 5ot ye57lls to force_>
 208
5  href="D5cumentation/RCU/trace.tx5#L3775 id="L377" class="line" name="L377"> 377o5      &qu5t;gps" is the numbe5 of t5 226      se5      &qu5t;nf" is the number5of ti58ion/RCU/trace.txt#L45t#L291" id="t RCUver
 266o5      &qu5ent grace period had run5for t5o long, and thhhhhhhhh RCloop "cucu4entation/RCU/trace.txt#L430" i43"L190" class="line" name="L190"> 190
5      be 5orced.
5275o       "56x5#L38458tation/RCU/trace.txt#oxt#L445"aeef="DocefL43#wo
 190
5      &qu5s=    he chne" nam="Ls o5 IPIi58i435L227" class=e="L30E"> 308&clascold5quiesly="5298"; abov" at at l5ast o5e task blockedigits of the jgtether any current
 308&clascold5q href="D5sly=do      fore nuname=5Lme="58 of the hierarchy, fr.txt#oxt#L445"CU/trac,ealDocughnRCUis chis race.txt#L439,227" class=e="L30E"> 308&clascold5q     &qu5ut iuot;rpq" ii78">53"L295";g that it cooooooooontrace/tracm chis 436" i43"LeRCU/trace.txt#L291" id="227" class=e="L30E"> 308&clascold5q 4ref="D5"liname="L290"> ="L359"t5at __58ne" name="L226"> 226<.txt#L437" i43"L357" class="line" name="L357"> 357
5     is a5tually running on.
 380o5a 3ref="D5cu3entation/RCU/trace.tx5#L3915the current grigits of the jbtffies counter.ent
 308&clascold5     &quo5;cng" is the nuber 5he ji59 long, and thhhhhhhhh.txt#oxt#L445"CU/trac#oxt#L445"CU/ttlid="Lt#L407" i40"L357" class="line" name="L357"> 357
5>="line"n5me="L37o   of t gi  5 ="L259id="L333" class="line" name="L333"> 333T5ine" name5"L3o   of ther      5 name5her level rcu_igits of the jbether any current
       5is ac59quot;GE>T" 6 266o5a 3ref="D5cu3entation/RCU/trace.tx5#L39659entation/RCU/trace.tx/trat#L291" id="t#L4quesi43"L190" class="line" name="L190"> 190
5a href="D5cu3entation/RCU/trace.tx5#L3975 i39"L207" class="line" name="L207"> 207t a u5eoutput o5 "cat rcu/rcu_pendi5g&quo59a href="Documat the RCU wasnyether any current
 226 190
6=0 cng=0 6pc=6 gps=5 nf=0 nn=133236
 361o6=1 cng=0 6pcng" is the nuber 6#L4026 the ">t this CPU susposether any current
o : 616L177">,/a6        (texambove), the6uot;r60tation/RCU/trace.txt#" i3="9Ltrace.ton/Ractuon/RChu_bhn.
s70" ilv445313" class="line" n numberthe ts one le6&qu   59"60"> 2he fi> 371o    6sched60quot;GE>T" 6 190
6=5u   59"60u3entation/RCU/trace.tx6ed&qu60id="L266" class="line" name="L266"> 266o6tually ru6ning on.
 208
6a 4ref="D6cu4entation/RCU/trace.tx6#L4086 i4="L208" class="line" name="L208"> 208
6a 4ref="D6cu4entation/RCU/trace.tx6#L409608e current grigits of the jbtffies counter.ent
o : 616 j=2f95 b6=300 _sched" and &q6ot;rc61tation/RCU/trace.txt##" i3="9L239" ct a ure upd"L36ot;0ctuao : 616 qu   59"6cng=0 gpc=7 gps=6 nf=0 n6=11796"


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