Support the preempt= boot option and patch the static call sites accordingly.
Unified · Split
| @@ -5328,9 +5328,75 @@ DEFINE_STATIC_CALL(preempt_schedule_notrace, __preempt_schedule_notrace_func); · 5327 unmodified lines | ||
| 5328 | 5328 | EXPORT_STATIC_CALL(preempt_schedule_notrace); |
| 5329 | 5329 | #endif |
| 5330 | 5330 | |
| 5331 | − | |
| 5332 | 5331 | #endif /* CONFIG_PREEMPTION */ |
| 5333 | 5332 | |
| 5333 | +#ifdef CONFIG_PREEMPT_DYNAMIC | |
| 5334 | + | |
| 5335 | +#include <linux/entry-common.h> | |
| 5336 | + | |
| 5337 | +/* | |
| 5338 | + * SC:cond_resched | |
| 5339 | + * SC:might_resched | |
| 5340 | + * SC:preempt_schedule | |
| 5341 | + * SC:preempt_schedule_notrace | |
| 5342 | + * SC:irqentry_exit_cond_resched | |
| 5343 | + * | |
| 5344 | + * | |
| 5345 | + * NONE: | |
| 5346 | + * cond_resched <- __cond_resched | |
| 5347 | + * might_resched <- RET0 | |
| 5348 | + * preempt_schedule <- NOP | |
| 5349 | + * preempt_schedule_notrace <- NOP | |
| 5350 | + * irqentry_exit_cond_resched <- NOP | |
| 5351 | + * | |
| 5352 | + * VOLUNTARY: | |
| 5353 | + * cond_resched <- __cond_resched | |
| 5354 | + * might_resched <- __cond_resched | |
| 5355 | + * preempt_schedule <- NOP | |
| 5356 | + * preempt_schedule_notrace <- NOP | |
| 5357 | + * irqentry_exit_cond_resched <- NOP | |
| 5358 | + * | |
| 5359 | + * FULL: | |
| 5360 | + * cond_resched <- RET0 | |
| 5361 | + * might_resched <- RET0 | |
| 5362 | + * preempt_schedule <- preempt_schedule | |
| 5363 | + * preempt_schedule_notrace <- preempt_schedule_notrace | |
| 5364 | + * irqentry_exit_cond_resched <- irqentry_exit_cond_resched | |
| 5365 | + */ | |
| 5366 | +static int __init setup_preempt_mode(char *str) | |
| 5367 | +{ | |
| 5368 | + if (!strcmp(str, "none")) { | |
| 5369 | + static_call_update(cond_resched, __cond_resched); | |
| 5370 | + static_call_update(might_resched, (typeof(&__cond_resched)) __static_call_return0); | |
| 5371 | + static_call_update(preempt_schedule, (typeof(&preempt_schedule)) NULL); | |
| 5372 | + static_call_update(preempt_schedule_notrace, (typeof(&preempt_schedule_notrace)) NULL); | |
| 5373 | + static_call_update(irqentry_exit_cond_resched, (typeof(&irqentry_exit_cond_resched)) NULL); | |
| 5374 | + pr_info("Dynamic Preempt: %s\n", str); | |
| 5375 | + } else if (!strcmp(str, "voluntary")) { | |
| 5376 | + static_call_update(cond_resched, __cond_resched); | |
| 5377 | + static_call_update(might_resched, __cond_resched); | |
| 5378 | + static_call_update(preempt_schedule, (typeof(&preempt_schedule)) NULL); | |
| 5379 | + static_call_update(preempt_schedule_notrace, (typeof(&preempt_schedule_notrace)) NULL); | |
| 5380 | + static_call_update(irqentry_exit_cond_resched, (typeof(&irqentry_exit_cond_resched)) NULL); | |
| 5381 | + pr_info("Dynamic Preempt: %s\n", str); | |
| 5382 | + } else if (!strcmp(str, "full")) { | |
| 5383 | + static_call_update(cond_resched, (typeof(&__cond_resched)) __static_call_return0); | |
| 5384 | + static_call_update(might_resched, (typeof(&__cond_resched)) __static_call_return0); | |
| 5385 | + static_call_update(preempt_schedule, __preempt_schedule_func); | |
| 5386 | + static_call_update(preempt_schedule_notrace, __preempt_schedule_notrace_func); | |
| 5387 | + static_call_update(irqentry_exit_cond_resched, irqentry_exit_cond_resched); | |
| 5388 | + pr_info("Dynamic Preempt: %s\n", str); | |
| 5389 | + } else { | |
| 5390 | + pr_warn("Dynamic Preempt: Unsupported preempt mode %s, default to full\n", str); | |
| 5391 | + return 1; | |
| 5392 | + } | |
| 5393 | + return 0; | |
| 5394 | +} | |
| 5395 | +__setup("preempt=", setup_preempt_mode); | |
| 5396 | + | |
| 5397 | +#endif /* CONFIG_PREEMPT_DYNAMIC */ | |
| 5398 | + | |
| 5399 | + | |
| 5334 | 5400 | /* |
| 5335 | 5401 | * This is the entry point to schedule() from kernel preemption |
| 5336 | 5402 | * off of irq context. |