code.ossystems Code Review - openembedded-core.git/blob

   1 From 8be4c8a38ee1e297578e094a6e4c143ec5259aba Mon Sep 17 00:00:00 2001
   2 From: Michael Jeanson <mjeanson@efficios.com>
   3 Date: Mon, 13 Sep 2021 12:00:38 -0400
   4 Subject: [PATCH 1/2] fix: cpu/hotplug: Remove deprecated CPU-hotplug
   5  functions. (v5.15)
   6
   7 The CPU-hotplug functions get|put_online_cpus() were deprecated in v4.13
   8 and removed in v5.15.
   9
  10 See upstream commits :
  11
  12 commit 8c854303ce0e38e5bbedd725ff39da7e235865d8
  13 Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
  14 Date:   Tue Aug 3 16:16:21 2021 +0200
  15
  16     cpu/hotplug: Remove deprecated CPU-hotplug functions.
  17
  18     No users in tree use the deprecated CPU-hotplug functions anymore.
  19
  20     Remove them.
  21
  22 Introduced in v4.13 :
  23
  24   commit 8f553c498e1772cccb39a114da4a498d22992758
  25   Author: Thomas Gleixner <tglx@linutronix.de>
  26   Date:   Wed May 24 10:15:12 2017 +0200
  27
  28     cpu/hotplug: Provide cpus_read|write_[un]lock()
  29
  30     The counting 'rwsem' hackery of get|put_online_cpus() is going to be
  31     replaced by percpu rwsem.
  32
  33     Rename the functions to make it clear that it's locking and not some
  34     refcount style interface. These new functions will be used for the
  35     preparatory patches which make the code ready for the percpu rwsem
  36     conversion.
  37
  38     Rename all instances in the cpu hotplug code while at it.
  39
  40 Upstream-Status: Backport [https://git.lttng.org/?p=lttng-modules.git;a=commit;h=ffcc873470121ef1ebb110df3d9038a38d9cb7cb]
  41
  42 Change-Id: I5a37cf5afc075a402b7347989fac637dfa60a1ed
  43 Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
  44 Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  45 ---
  46  include/wrapper/cpu.h                     | 44 +++++++++++++++++++++++
  47  src/lib/ringbuffer/ring_buffer_backend.c  |  8 ++---
  48  src/lib/ringbuffer/ring_buffer_frontend.c | 17 ++++-----
  49  src/lib/ringbuffer/ring_buffer_iterator.c | 15 ++++----
  50  src/lttng-context-perf-counters.c         | 11 +++---
  51  src/lttng-statedump-impl.c                |  6 ++--
  52  6 files changed, 74 insertions(+), 27 deletions(-)
  53  create mode 100644 include/wrapper/cpu.h
  54
  55 diff --git a/include/wrapper/cpu.h b/include/wrapper/cpu.h
  56 new file mode 100644
  57 index 00000000..cbee1962
  58 --- /dev/null
  59 +++ b/include/wrapper/cpu.h
  60 @@ -0,0 +1,44 @@
  61 +/* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
  62 + *
  63 + * wrapper/cpu.h
  64 + *
  65 + * Copyright (C) 2021 Michael Jeanson <mjeanson@efficios.com>
  66 + */
  67 +
  68 +#ifndef _LTTNG_WRAPPER_CPU_H
  69 +#define _LTTNG_WRAPPER_CPU_H
  70 +
  71 +#include <linux/cpu.h>
  72 +#include <lttng/kernel-version.h>
  73 +
  74 +#if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,13,0))
  75 +
  76 +static inline
  77 +void lttng_cpus_read_lock(void)
  78 +{
  79 +       cpus_read_lock();
  80 +}
  81 +
  82 +static inline
  83 +void lttng_cpus_read_unlock(void)
  84 +{
  85 +       cpus_read_unlock();
  86 +}
  87 +
  88 +#else /* LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,13,0) */
  89 +
  90 +static inline
  91 +void lttng_cpus_read_lock(void)
  92 +{
  93 +       get_online_cpus();
  94 +}
  95 +
  96 +static inline
  97 +void lttng_cpus_read_unlock(void)
  98 +{
  99 +       put_online_cpus();
 100 +}
 101 +
 102 +#endif /* LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,13,0) */
 103 +
 104 +#endif /* _LTTNG_WRAPPER_CPU_H */
 105 diff --git a/src/lib/ringbuffer/ring_buffer_backend.c b/src/lib/ringbuffer/ring_buffer_backend.c
 106 index 26efb2bc..9a339be0 100644
 107 --- a/src/lib/ringbuffer/ring_buffer_backend.c
 108 +++ b/src/lib/ringbuffer/ring_buffer_backend.c
 109 @@ -12,10 +12,10 @@
 110  #include <linux/delay.h>
 111  #include <linux/errno.h>
 112  #include <linux/slab.h>
 113 -#include <linux/cpu.h>
 114  #include <linux/mm.h>
 115  #include <linux/vmalloc.h>
 116
 117 +#include <wrapper/cpu.h>
 118  #include <wrapper/mm.h>
 119  #include <wrapper/vmalloc.h>   /* for wrapper_vmalloc_sync_mappings() */
 120  #include <ringbuffer/config.h>
 121 @@ -445,14 +445,14 @@ int channel_backend_init(struct channel_backend *chanb,
 122                         chanb->cpu_hp_notifier.priority = 5;
 123                         register_hotcpu_notifier(&chanb->cpu_hp_notifier);
 124
 125 -                       get_online_cpus();
 126 +                       lttng_cpus_read_lock();
 127                         for_each_online_cpu(i) {
 128                                 ret = lib_ring_buffer_create(per_cpu_ptr(chanb->buf, i),
 129                                                          chanb, i);
 130                                 if (ret)
 131                                         goto free_bufs; /* cpu hotplug locked */
 132                         }
 133 -                       put_online_cpus();
 134 +                       lttng_cpus_read_unlock();
 135  #else
 136                         for_each_possible_cpu(i) {
 137                                 ret = lib_ring_buffer_create(per_cpu_ptr(chanb->buf, i),
 138 @@ -485,7 +485,7 @@ free_bufs:
 139                  */
 140  #else /* #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0)) */
 141  #ifdef CONFIG_HOTPLUG_CPU
 142 -               put_online_cpus();
 143 +               lttng_cpus_read_unlock();
 144                 unregister_hotcpu_notifier(&chanb->cpu_hp_notifier);
 145  #endif
 146  #endif /* #else #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0)) */
 147 diff --git a/src/lib/ringbuffer/ring_buffer_frontend.c b/src/lib/ringbuffer/ring_buffer_frontend.c
 148 index e9056118..87a575d0 100644
 149 --- a/src/lib/ringbuffer/ring_buffer_frontend.c
 150 +++ b/src/lib/ringbuffer/ring_buffer_frontend.c
 151 @@ -48,6 +48,7 @@
 152  #include <ringbuffer/iterator.h>
 153  #include <ringbuffer/nohz.h>
 154  #include <wrapper/atomic.h>
 155 +#include <wrapper/cpu.h>
 156  #include <wrapper/kref.h>
 157  #include <wrapper/percpu-defs.h>
 158  #include <wrapper/timer.h>
 159 @@ -724,7 +725,7 @@ static void channel_unregister_notifiers(struct lttng_kernel_ring_buffer_channel
 160                         int cpu;
 161
 162  #ifdef CONFIG_HOTPLUG_CPU
 163 -                       get_online_cpus();
 164 +                       lttng_cpus_read_lock();
 165                         chan->cpu_hp_enable = 0;
 166                         for_each_online_cpu(cpu) {
 167                                 struct lttng_kernel_ring_buffer *buf = per_cpu_ptr(chan->backend.buf,
 168 @@ -732,7 +733,7 @@ static void channel_unregister_notifiers(struct lttng_kernel_ring_buffer_channel
 169                                 lib_ring_buffer_stop_switch_timer(buf);
 170                                 lib_ring_buffer_stop_read_timer(buf);
 171                         }
 172 -                       put_online_cpus();
 173 +                       lttng_cpus_read_unlock();
 174                         unregister_cpu_notifier(&chan->cpu_hp_notifier);
 175  #else
 176                         for_each_possible_cpu(cpu) {
 177 @@ -772,14 +773,14 @@ void lib_ring_buffer_set_quiescent_channel(struct lttng_kernel_ring_buffer_chann
 178         const struct lttng_kernel_ring_buffer_config *config = &chan->backend.config;
 179
 180         if (config->alloc == RING_BUFFER_ALLOC_PER_CPU) {
 181 -               get_online_cpus();
 182 +               lttng_cpus_read_lock();
 183                 for_each_channel_cpu(cpu, chan) {
 184                         struct lttng_kernel_ring_buffer *buf = per_cpu_ptr(chan->backend.buf,
 185                                                               cpu);
 186
 187                         lib_ring_buffer_set_quiescent(buf);
 188                 }
 189 -               put_online_cpus();
 190 +               lttng_cpus_read_unlock();
 191         } else {
 192                 struct lttng_kernel_ring_buffer *buf = chan->backend.buf;
 193
 194 @@ -794,14 +795,14 @@ void lib_ring_buffer_clear_quiescent_channel(struct lttng_kernel_ring_buffer_cha
 195         const struct lttng_kernel_ring_buffer_config *config = &chan->backend.config;
 196
 197         if (config->alloc == RING_BUFFER_ALLOC_PER_CPU) {
 198 -               get_online_cpus();
 199 +               lttng_cpus_read_lock();
 200                 for_each_channel_cpu(cpu, chan) {
 201                         struct lttng_kernel_ring_buffer *buf = per_cpu_ptr(chan->backend.buf,
 202                                                               cpu);
 203
 204                         lib_ring_buffer_clear_quiescent(buf);
 205                 }
 206 -               put_online_cpus();
 207 +               lttng_cpus_read_unlock();
 208         } else {
 209                 struct lttng_kernel_ring_buffer *buf = chan->backend.buf;
 210
 211 @@ -899,7 +900,7 @@ struct lttng_kernel_ring_buffer_channel *channel_create(const struct lttng_kerne
 212                         chan->cpu_hp_notifier.priority = 6;
 213                         register_cpu_notifier(&chan->cpu_hp_notifier);
 214
 215 -                       get_online_cpus();
 216 +                       lttng_cpus_read_lock();
 217                         for_each_online_cpu(cpu) {
 218                                 struct lttng_kernel_ring_buffer *buf = per_cpu_ptr(chan->backend.buf,
 219                                                                        cpu);
 220 @@ -909,7 +910,7 @@ struct lttng_kernel_ring_buffer_channel *channel_create(const struct lttng_kerne
 221                                 spin_unlock(&per_cpu(ring_buffer_nohz_lock, cpu));
 222                         }
 223                         chan->cpu_hp_enable = 1;
 224 -                       put_online_cpus();
 225 +                       lttng_cpus_read_unlock();
 226  #else
 227                         for_each_possible_cpu(cpu) {
 228                                 struct lttng_kernel_ring_buffer *buf = per_cpu_ptr(chan->backend.buf,
 229 diff --git a/src/lib/ringbuffer/ring_buffer_iterator.c b/src/lib/ringbuffer/ring_buffer_iterator.c
 230 index 25839af6..60c95ca6 100644
 231 --- a/src/lib/ringbuffer/ring_buffer_iterator.c
 232 +++ b/src/lib/ringbuffer/ring_buffer_iterator.c
 233 @@ -10,6 +10,7 @@
 234   */
 235
 236  #include <ringbuffer/iterator.h>
 237 +#include <wrapper/cpu.h>
 238  #include <wrapper/file.h>
 239  #include <wrapper/uaccess.h>
 240  #include <linux/jiffies.h>
 241 @@ -440,13 +441,13 @@ int channel_iterator_init(struct lttng_kernel_ring_buffer_channel *chan)
 242                         chan->hp_iter_notifier.priority = 10;
 243                         register_cpu_notifier(&chan->hp_iter_notifier);
 244
 245 -                       get_online_cpus();
 246 +                       lttng_cpus_read_lock();
 247                         for_each_online_cpu(cpu) {
 248                                 buf = per_cpu_ptr(chan->backend.buf, cpu);
 249                                 lib_ring_buffer_iterator_init(chan, buf);
 250                         }
 251                         chan->hp_iter_enable = 1;
 252 -                       put_online_cpus();
 253 +                       lttng_cpus_read_unlock();
 254  #else
 255                         for_each_possible_cpu(cpu) {
 256                                 buf = per_cpu_ptr(chan->backend.buf, cpu);
 257 @@ -519,7 +520,7 @@ int channel_iterator_open(struct lttng_kernel_ring_buffer_channel *chan)
 258         CHAN_WARN_ON(chan, config->output != RING_BUFFER_ITERATOR);
 259
 260         if (config->alloc == RING_BUFFER_ALLOC_PER_CPU) {
 261 -               get_online_cpus();
 262 +               lttng_cpus_read_lock();
 263                 /* Allow CPU hotplug to keep track of opened reader */
 264                 chan->iter.read_open = 1;
 265                 for_each_channel_cpu(cpu, chan) {
 266 @@ -529,7 +530,7 @@ int channel_iterator_open(struct lttng_kernel_ring_buffer_channel *chan)
 267                                 goto error;
 268                         buf->iter.read_open = 1;
 269                 }
 270 -               put_online_cpus();
 271 +               lttng_cpus_read_unlock();
 272         } else {
 273                 buf = channel_get_ring_buffer(config, chan, 0);
 274                 ret = lib_ring_buffer_iterator_open(buf);
 275 @@ -538,7 +539,7 @@ int channel_iterator_open(struct lttng_kernel_ring_buffer_channel *chan)
 276  error:
 277         /* Error should always happen on CPU 0, hence no close is required. */
 278         CHAN_WARN_ON(chan, cpu != 0);
 279 -       put_online_cpus();
 280 +       lttng_cpus_read_unlock();
 281         return ret;
 282  }
 283  EXPORT_SYMBOL_GPL(channel_iterator_open);
 284 @@ -550,7 +551,7 @@ void channel_iterator_release(struct lttng_kernel_ring_buffer_channel *chan)
 285         int cpu;
 286
 287         if (config->alloc == RING_BUFFER_ALLOC_PER_CPU) {
 288 -               get_online_cpus();
 289 +               lttng_cpus_read_lock();
 290                 for_each_channel_cpu(cpu, chan) {
 291                         buf = channel_get_ring_buffer(config, chan, cpu);
 292                         if (buf->iter.read_open) {
 293 @@ -559,7 +560,7 @@ void channel_iterator_release(struct lttng_kernel_ring_buffer_channel *chan)
 294                         }
 295                 }
 296                 chan->iter.read_open = 0;
 297 -               put_online_cpus();
 298 +               lttng_cpus_read_unlock();
 299         } else {
 300                 buf = channel_get_ring_buffer(config, chan, 0);
 301                 lib_ring_buffer_iterator_release(buf);
 302 diff --git a/src/lttng-context-perf-counters.c b/src/lttng-context-perf-counters.c
 303 index b0227d47..372f05e0 100644
 304 --- a/src/lttng-context-perf-counters.c
 305 +++ b/src/lttng-context-perf-counters.c
 306 @@ -16,6 +16,7 @@
 307  #include <lttng/events.h>
 308  #include <lttng/events-internal.h>
 309  #include <ringbuffer/frontend_types.h>
 310 +#include <wrapper/cpu.h>
 311  #include <wrapper/vmalloc.h>
 312  #include <wrapper/perf.h>
 313  #include <lttng/tracer.h>
 314 @@ -97,10 +98,10 @@ void lttng_destroy_perf_counter_ctx_field(void *priv)
 315         {
 316                 int cpu;
 317
 318 -               get_online_cpus();
 319 +               lttng_cpus_read_lock();
 320                 for_each_online_cpu(cpu)
 321                         perf_event_release_kernel(events[cpu]);
 322 -               put_online_cpus();
 323 +               lttng_cpus_read_unlock();
 324  #ifdef CONFIG_HOTPLUG_CPU
 325                 unregister_cpu_notifier(&perf_field->nb);
 326  #endif
 327 @@ -304,7 +305,7 @@ int lttng_add_perf_counter_to_ctx(uint32_t type,
 328                 perf_field->nb.priority = 0;
 329                 register_cpu_notifier(&perf_field->nb);
 330  #endif
 331 -               get_online_cpus();
 332 +               lttng_cpus_read_lock();
 333                 for_each_online_cpu(cpu) {
 334                         events[cpu] = wrapper_perf_event_create_kernel_counter(attr,
 335                                                 cpu, NULL, overflow_callback);
 336 @@ -317,7 +318,7 @@ int lttng_add_perf_counter_to_ctx(uint32_t type,
 337                                 goto counter_busy;
 338                         }
 339                 }
 340 -               put_online_cpus();
 341 +               lttng_cpus_read_unlock();
 342                 perf_field->hp_enable = 1;
 343         }
 344  #endif /* #else #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0)) */
 345 @@ -351,7 +352,7 @@ counter_error:
 346                         if (events[cpu] && !IS_ERR(events[cpu]))
 347                                 perf_event_release_kernel(events[cpu]);
 348                 }
 349 -               put_online_cpus();
 350 +               lttng_cpus_read_unlock();
 351  #ifdef CONFIG_HOTPLUG_CPU
 352                 unregister_cpu_notifier(&perf_field->nb);
 353  #endif
 354 diff --git a/src/lttng-statedump-impl.c b/src/lttng-statedump-impl.c
 355 index 4dfbca0b..2b42783a 100644
 356 --- a/src/lttng-statedump-impl.c
 357 +++ b/src/lttng-statedump-impl.c
 358 @@ -23,7 +23,6 @@
 359  #include <linux/file.h>
 360  #include <linux/interrupt.h>
 361  #include <linux/irqnr.h>
 362 -#include <linux/cpu.h>
 363  #include <linux/netdevice.h>
 364  #include <linux/inetdevice.h>
 365  #include <linux/mm.h>
 366 @@ -34,6 +33,7 @@
 367
 368  #include <lttng/events.h>
 369  #include <lttng/tracer.h>
 370 +#include <wrapper/cpu.h>
 371  #include <wrapper/irqdesc.h>
 372  #include <wrapper/fdtable.h>
 373  #include <wrapper/namespace.h>
 374 @@ -770,7 +770,7 @@ int do_lttng_statedump(struct lttng_kernel_session *session)
 375          * is to guarantee that each CPU has been in a state where is was in
 376          * syscall mode (i.e. not in a trap, an IRQ or a soft IRQ).
 377          */
 378 -       get_online_cpus();
 379 +       lttng_cpus_read_lock();
 380         atomic_set(&kernel_threads_to_run, num_online_cpus());
 381         for_each_online_cpu(cpu) {
 382                 INIT_DELAYED_WORK(&cpu_work[cpu], lttng_statedump_work_func);
 383 @@ -778,7 +778,7 @@ int do_lttng_statedump(struct lttng_kernel_session *session)
 384         }
 385         /* Wait for all threads to run */
 386         __wait_event(statedump_wq, (atomic_read(&kernel_threads_to_run) == 0));
 387 -       put_online_cpus();
 388 +       lttng_cpus_read_unlock();
 389         /* Our work is done */
 390         trace_lttng_statedump_end(session);
 391         return 0;
 392 --
 393 2.19.1
 394