Commit a30489c5228fba6f16b4c740a0292879ef13371e
Committed by
Paul E. McKenney
Paul E. McKenney
1 parent
40694d6644
Exists in
smarc-l5.0.0_1.0.0-ga
and in
5 other branches
rcu: Instrument synchronize_rcu_expedited() for debugfs tracing
This commit adds the counters to rcu_state and updates them in synchronize_rcu_expedited() to provide the data needed for debugfs tracing. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Showing 2 changed files with 24 additions and 3 deletions Side-by-side Diff
kernel/rcutree.c
| ... | ... | @@ -2321,6 +2321,7 @@ |
| 2321 | 2321 | (ulong)atomic_long_read(&rsp->expedited_done) + |
| 2322 | 2322 | ULONG_MAX / 8)) { |
| 2323 | 2323 | synchronize_sched(); |
| 2324 | + atomic_long_inc(&rsp->expedited_wrap); | |
| 2324 | 2325 | return; |
| 2325 | 2326 | } |
| 2326 | 2327 | |
| 2327 | 2328 | |
| ... | ... | @@ -2341,11 +2342,14 @@ |
| 2341 | 2342 | synchronize_sched_expedited_cpu_stop, |
| 2342 | 2343 | NULL) == -EAGAIN) { |
| 2343 | 2344 | put_online_cpus(); |
| 2345 | + atomic_long_inc(&rsp->expedited_tryfail); | |
| 2344 | 2346 | |
| 2345 | 2347 | /* Check to see if someone else did our work for us. */ |
| 2346 | 2348 | s = atomic_long_read(&rsp->expedited_done); |
| 2347 | 2349 | if (ULONG_CMP_GE((ulong)s, (ulong)firstsnap)) { |
| 2348 | - smp_mb(); /* ensure test happens before caller kfree */ | |
| 2350 | + /* ensure test happens before caller kfree */ | |
| 2351 | + smp_mb__before_atomic_inc(); /* ^^^ */ | |
| 2352 | + atomic_long_inc(&rsp->expedited_workdone1); | |
| 2349 | 2353 | return; |
| 2350 | 2354 | } |
| 2351 | 2355 | |
| 2352 | 2356 | |
| ... | ... | @@ -2354,13 +2358,16 @@ |
| 2354 | 2358 | udelay(trycount * num_online_cpus()); |
| 2355 | 2359 | } else { |
| 2356 | 2360 | synchronize_sched(); |
| 2361 | + atomic_long_inc(&rsp->expedited_normal); | |
| 2357 | 2362 | return; |
| 2358 | 2363 | } |
| 2359 | 2364 | |
| 2360 | 2365 | /* Recheck to see if someone else did our work for us. */ |
| 2361 | 2366 | s = atomic_long_read(&rsp->expedited_done); |
| 2362 | 2367 | if (ULONG_CMP_GE((ulong)s, (ulong)firstsnap)) { |
| 2363 | - smp_mb(); /* ensure test happens before caller kfree */ | |
| 2368 | + /* ensure test happens before caller kfree */ | |
| 2369 | + smp_mb__before_atomic_inc(); /* ^^^ */ | |
| 2370 | + atomic_long_inc(&rsp->expedited_workdone2); | |
| 2364 | 2371 | return; |
| 2365 | 2372 | } |
| 2366 | 2373 | |
| ... | ... | @@ -2375,6 +2382,7 @@ |
| 2375 | 2382 | snap = atomic_long_read(&rsp->expedited_start); |
| 2376 | 2383 | smp_mb(); /* ensure read is before try_stop_cpus(). */ |
| 2377 | 2384 | } |
| 2385 | + atomic_long_inc(&rsp->expedited_stoppedcpus); | |
| 2378 | 2386 | |
| 2379 | 2387 | /* |
| 2380 | 2388 | * Everyone up to our most recent fetch is covered by our grace |
| 2381 | 2389 | |
| 2382 | 2390 | |
| ... | ... | @@ -2383,12 +2391,16 @@ |
| 2383 | 2391 | * than we did already did their update. |
| 2384 | 2392 | */ |
| 2385 | 2393 | do { |
| 2394 | + atomic_long_inc(&rsp->expedited_done_tries); | |
| 2386 | 2395 | s = atomic_long_read(&rsp->expedited_done); |
| 2387 | 2396 | if (ULONG_CMP_GE((ulong)s, (ulong)snap)) { |
| 2388 | - smp_mb(); /* ensure test happens before caller kfree */ | |
| 2397 | + /* ensure test happens before caller kfree */ | |
| 2398 | + smp_mb__before_atomic_inc(); /* ^^^ */ | |
| 2399 | + atomic_long_inc(&rsp->expedited_done_lost); | |
| 2389 | 2400 | break; |
| 2390 | 2401 | } |
| 2391 | 2402 | } while (atomic_long_cmpxchg(&rsp->expedited_done, s, snap) != s); |
| 2403 | + atomic_long_inc(&rsp->expedited_done_exit); | |
| 2392 | 2404 | |
| 2393 | 2405 | put_online_cpus(); |
| 2394 | 2406 | } |
kernel/rcutree.h
| ... | ... | @@ -406,6 +406,15 @@ |
| 406 | 406 | |
| 407 | 407 | atomic_long_t expedited_start; /* Starting ticket. */ |
| 408 | 408 | atomic_long_t expedited_done; /* Done ticket. */ |
| 409 | + atomic_long_t expedited_wrap; /* # near-wrap incidents. */ | |
| 410 | + atomic_long_t expedited_tryfail; /* # acquisition failures. */ | |
| 411 | + atomic_long_t expedited_workdone1; /* # done by others #1. */ | |
| 412 | + atomic_long_t expedited_workdone2; /* # done by others #2. */ | |
| 413 | + atomic_long_t expedited_normal; /* # fallbacks to normal. */ | |
| 414 | + atomic_long_t expedited_stoppedcpus; /* # successful stop_cpus. */ | |
| 415 | + atomic_long_t expedited_done_tries; /* # tries to update _done. */ | |
| 416 | + atomic_long_t expedited_done_lost; /* # times beaten to _done. */ | |
| 417 | + atomic_long_t expedited_done_exit; /* # times exited _done loop. */ | |
| 409 | 418 | |
| 410 | 419 | unsigned long jiffies_force_qs; /* Time at which to invoke */ |
| 411 | 420 | /* force_quiescent_state(). */ |