1 // SPDX-License-Identifier: GPL-2.0-only
11  * There are three threads running per CPU:
13  * 1) one per-CPU thread takes a per-page pthread_mutex in a random
15  *    area_src), and increments a per-page counter in the same page,
18  * 2) another per-CPU thread handles the userfaults generated by
22  * 3) one last per-CPU thread transfers the memory in the background
24  *    2). Each cpu thread takes cares of transferring a portion of the
32  * per-CPU threads 1 by triggering userfaults inside
37 #include "uffd-common.h"
57 	"./uffd-stress anon 100 99999\n\n"
59 	"./uffd-stress shmem 1000 99\n\n"
61 	"./uffd-stress hugetlb 256 50\n\n"
63 	"./uffd-stress hugetlb-private 256 50\n\n"
64 	"# 10MiB-~6GiB 999 bounces anonymous test, "
66 	"while ./uffd-stress anon $[RANDOM % 6000 + 10] 999; do true; done\n\n";
70 	fprintf(stderr, "\nUsage: ./uffd-stress <test type> <MiB> <bounces>\n\n");  in usage()
72 		"hugetlb-private, shmem, shmem-private\n\n");  in usage()
83 		args[i].cpu = i;  in uffd_stats_reset()
93 	unsigned long cpu = (unsigned long) arg;  in locking_thread()  local
98 		page_nr = -bounces;  in locking_thread()
100 			page_nr += cpu * nr_pages_per_cpu;  in locking_thread()
149 	unsigned long cpu = (unsigned long) arg;  in background_thread()  local
152 	start_nr = cpu * nr_pages_per_cpu;  in background_thread()
153 	end_nr = (cpu+1) * nr_pages_per_cpu;  in background_thread()
161 	 * If we need to test uffd-wp, set it up now.  Then we'll have  in background_thread()
163 	 * can be write-protected for testing  in background_thread()
181 	unsigned long cpu;  in stress()  local
187 	for (cpu = 0; cpu < nr_cpus; cpu++) {  in stress()
188 		if (pthread_create(&locking_threads[cpu], &attr,  in stress()
189 				   locking_thread, (void *)cpu))  in stress()
192 			if (pthread_create(&uffd_threads[cpu], &attr, uffd_poll_thread, &args[cpu]))  in stress()
195 			if (pthread_create(&uffd_threads[cpu], &attr,  in stress()
197 					   (void *)&args[cpu]))  in stress()
201 		if (pthread_create(&background_threads[cpu], &attr,  in stress()
202 				   background_thread, (void *)cpu))  in stress()
205 	for (cpu = 0; cpu < nr_cpus; cpu++)  in stress()
206 		if (pthread_join(background_threads[cpu], NULL))  in stress()
214 	 * area_src (but they're guaranteed to get -EEXIST from  in stress()
218 	uffd_test_ops->release_pages(area_src);  in stress()
221 	for (cpu = 0; cpu < nr_cpus; cpu++)  in stress()
222 		if (pthread_join(locking_threads[cpu], NULL))  in stress()
225 	for (cpu = 0; cpu < nr_cpus; cpu++) {  in stress()
228 			if (write(pipefd[cpu*2+1], &c, 1) != 1)  in stress()
230 			if (pthread_join(uffd_threads[cpu],  in stress()
231 					 (void *)&args[cpu]))  in stress()
234 			if (pthread_cancel(uffd_threads[cpu]))  in stress()
236 			if (pthread_join(uffd_threads[cpu], NULL))  in stress()
247 	unsigned long nr;  in userfaultfd_stress()  local
266 	while (bounces--) {  in userfaultfd_stress()
305 		 * return -EEXIST). The problem comes at the next  in userfaultfd_stress()
310 		 * area_src would lead to -EEXIST failure during the  in userfaultfd_stress()
321 		uffd_test_ops->release_pages(area_dst);  in userfaultfd_stress()
344 			for (nr = 0; nr < nr_pages; nr++)  in userfaultfd_stress()
345 				if (*area_count(area_dst, nr) != count_verify[nr])  in userfaultfd_stress()
347 					    *area_count(area_src, nr),  in userfaultfd_stress()
348 					    count_verify[nr], nr);  in userfaultfd_stress()
370 	} else if (!strcmp(type, "hugetlb-private")) {  in set_test_type()
377 	} else if (!strcmp(type, "shmem-private")) {  in set_test_type()
416 	uffd = -1;  in parse_test_type_arg()