[RFC PATCH 0/2] KVM: selftests: Rename perf_test_util to memstress

[RFC PATCH 0/2] KVM: selftests: Rename perf_test_util to memstress

[David Matlack]

This series renames the perf_test_util to memstress. patch 1 renames the files
perf_test_util.[ch] to memstress.[ch], and patch 2 replaces the perf_test_
prefix on symbols with memstress_.

The reason for this rename, as with any rename, is to improve readability.
perf_test_util is too generic and does not describe at all what the library
does, other than being used for perf tests.

I considered a lot of different names (naming is hard) and eventually settled
on memstress for a few reasons:

 - "memstress" better describes the functionality proveded by this library,
   which is to run a VM that reads/writes to memory from all vCPUs in parallel
   (i.e. stressing VM memory).

 - "memstress" contains the same number of characters as "perf_test", making
   it a drop in replacement in symbols wihout changing line lengths.

 - The lack of underscore between "mem" and "stress" makes it clear "memstress"
   is a noun, avoiding confusion in function names.

Looking to the future, I think "memstress" will remain a good name. Specifically
there are some in-flight improvements that will make this library even more of
a "memory stress tester":

 - A proposed series by yours truly [1] extends memstress/perf_test_util to
   support execute from memory, in addition to reading/writing.

 - Colton Lewis within Google is looking into adding support for more complex
   memory access patterns.

[1] https://lore.kernel.org/kvm/20220401233737.3021889-2-dmatlack@google.com/

David Matlack (2):
  KVM: selftests: Rename perf_test_util.[ch] to memstress.[ch]
  KVM: selftests: Rename perf_test symbols to memstress

 tools/testing/selftests/kvm/Makefile          |  4 +-
 .../selftests/kvm/access_tracking_perf_test.c | 20 +++----
 .../selftests/kvm/demand_paging_test.c        | 20 +++----
 .../selftests/kvm/dirty_log_perf_test.c       | 22 ++++----
 .../include/{perf_test_util.h => memstress.h} | 34 ++++++------
 .../kvm/lib/{perf_test_util.c => memstress.c} | 54 +++++++++----------
 .../x86_64/{perf_test_util.c => memstress.c}  | 36 ++++++-------
 .../kvm/memslot_modification_stress_test.c    | 16 +++---
 8 files changed, 103 insertions(+), 103 deletions(-)
 rename tools/testing/selftests/kvm/include/{perf_test_util.h => memstress.h} (50%)
 rename tools/testing/selftests/kvm/lib/{perf_test_util.c => memstress.c} (83%)
 rename tools/testing/selftests/kvm/lib/x86_64/{perf_test_util.c => memstress.c} (68%)


base-commit: 1a4d88a361af4f2e91861d632c6a1fe87a9665c2
prerequisite-patch-id: 8c230105c8a2f1245dedb5b386327d98865d0bb2
prerequisite-patch-id: 9b4329037e2e880db19f3221e47d956b78acadc8
-- 
2.37.1.359.gd136c6c3e2-goog

[RFC PATCH 1/2] KVM: selftests: Rename perf_test_util.[ch] to memstress.[ch]

[David Matlack]

Rename the perf_test_util.[ch] files to memstress.[ch]. Symbols are
renamed in the following commit to reduce the amount of churn here in
hopes of playiing nice with git's file rename detection.

The name "memstress" was chosen to better describe the functionality
proveded by this library, which is to create and run a VM that
reads/writes to guest memory on all vCPUs in parallel.

"memstress" also contains the same number of chracters as "perf_test",
making it a drop-in replacement in symbols, e.g. function names, without
impacting line lengths. Also the lack of underscore between "mem" and
"stress" makes it clear "memstress" is a noun.

Signed-off-by: David Matlack <dmatlack@google.com>
---
 tools/testing/selftests/kvm/Makefile                      | 4 ++--
 tools/testing/selftests/kvm/access_tracking_perf_test.c   | 2 +-
 tools/testing/selftests/kvm/demand_paging_test.c          | 2 +-
 tools/testing/selftests/kvm/dirty_log_perf_test.c         | 2 +-
 .../kvm/include/{perf_test_util.h => memstress.h}         | 8 ++++----
 .../selftests/kvm/lib/{perf_test_util.c => memstress.c}   | 2 +-
 .../kvm/lib/x86_64/{perf_test_util.c => memstress.c}      | 4 ++--
 .../selftests/kvm/memslot_modification_stress_test.c      | 2 +-
 8 files changed, 13 insertions(+), 13 deletions(-)
 rename tools/testing/selftests/kvm/include/{perf_test_util.h => memstress.h} (89%)
 rename tools/testing/selftests/kvm/lib/{perf_test_util.c => memstress.c} (99%)
 rename tools/testing/selftests/kvm/lib/x86_64/{perf_test_util.c => memstress.c} (97%)

diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index 690b499c3471..754c09e4df62 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -42,14 +42,14 @@ LIBKVM += lib/elf.c
 LIBKVM += lib/guest_modes.c
 LIBKVM += lib/io.c
 LIBKVM += lib/kvm_util.c
-LIBKVM += lib/perf_test_util.c
+LIBKVM += lib/memstress.c
 LIBKVM += lib/rbtree.c
 LIBKVM += lib/sparsebit.c
 LIBKVM += lib/test_util.c
 
 LIBKVM_x86_64 += lib/x86_64/apic.c
 LIBKVM_x86_64 += lib/x86_64/handlers.S
-LIBKVM_x86_64 += lib/x86_64/perf_test_util.c
+LIBKVM_x86_64 += lib/x86_64/memstress.c
 LIBKVM_x86_64 += lib/x86_64/processor.c
 LIBKVM_x86_64 += lib/x86_64/svm.c
 LIBKVM_x86_64 += lib/x86_64/ucall.c
diff --git a/tools/testing/selftests/kvm/access_tracking_perf_test.c b/tools/testing/selftests/kvm/access_tracking_perf_test.c
index 1c2749b1481a..9c9a78ec9134 100644
--- a/tools/testing/selftests/kvm/access_tracking_perf_test.c
+++ b/tools/testing/selftests/kvm/access_tracking_perf_test.c
@@ -43,7 +43,7 @@
 
 #include "kvm_util.h"
 #include "test_util.h"
-#include "perf_test_util.h"
+#include "memstress.h"
 #include "guest_modes.h"
 
 /* Global variable used to synchronize all of the vCPU threads. */
diff --git a/tools/testing/selftests/kvm/demand_paging_test.c b/tools/testing/selftests/kvm/demand_paging_test.c
index 779ae54f89c4..8b53ffeaaa73 100644
--- a/tools/testing/selftests/kvm/demand_paging_test.c
+++ b/tools/testing/selftests/kvm/demand_paging_test.c
@@ -20,7 +20,7 @@
 
 #include "kvm_util.h"
 #include "test_util.h"
-#include "perf_test_util.h"
+#include "memstress.h"
 #include "guest_modes.h"
 
 #ifdef __NR_userfaultfd
diff --git a/tools/testing/selftests/kvm/dirty_log_perf_test.c b/tools/testing/selftests/kvm/dirty_log_perf_test.c
index f99e39a672d3..769ab87cadcc 100644
--- a/tools/testing/selftests/kvm/dirty_log_perf_test.c
+++ b/tools/testing/selftests/kvm/dirty_log_perf_test.c
@@ -16,7 +16,7 @@
 
 #include "kvm_util.h"
 #include "test_util.h"
-#include "perf_test_util.h"
+#include "memstress.h"
 #include "guest_modes.h"
 
 #ifdef __aarch64__
diff --git a/tools/testing/selftests/kvm/include/perf_test_util.h b/tools/testing/selftests/kvm/include/memstress.h
similarity index 89%
rename from tools/testing/selftests/kvm/include/perf_test_util.h
rename to tools/testing/selftests/kvm/include/memstress.h
index eaa88df0555a..e72dfb43e456 100644
--- a/tools/testing/selftests/kvm/include/perf_test_util.h
+++ b/tools/testing/selftests/kvm/include/memstress.h
@@ -1,12 +1,12 @@
 // SPDX-License-Identifier: GPL-2.0
 /*
- * tools/testing/selftests/kvm/include/perf_test_util.h
+ * tools/testing/selftests/kvm/include/memstress.h
  *
  * Copyright (C) 2020, Google LLC.
  */
 
-#ifndef SELFTEST_KVM_PERF_TEST_UTIL_H
-#define SELFTEST_KVM_PERF_TEST_UTIL_H
+#ifndef SELFTEST_KVM_MEMSTRESS_H
+#define SELFTEST_KVM_MEMSTRESS_H
 
 #include <pthread.h>
 
@@ -60,4 +60,4 @@ void perf_test_guest_code(uint32_t vcpu_id);
 uint64_t perf_test_nested_pages(int nr_vcpus);
 void perf_test_setup_nested(struct kvm_vm *vm, int nr_vcpus, struct kvm_vcpu *vcpus[]);
 
-#endif /* SELFTEST_KVM_PERF_TEST_UTIL_H */
+#endif /* SELFTEST_KVM_MEMSTRESS_H */
diff --git a/tools/testing/selftests/kvm/lib/perf_test_util.c b/tools/testing/selftests/kvm/lib/memstress.c
similarity index 99%
rename from tools/testing/selftests/kvm/lib/perf_test_util.c
rename to tools/testing/selftests/kvm/lib/memstress.c
index 9618b37c66f7..d3aea9e4f6a1 100644
--- a/tools/testing/selftests/kvm/lib/perf_test_util.c
+++ b/tools/testing/selftests/kvm/lib/memstress.c
@@ -5,7 +5,7 @@
 #include <inttypes.h>
 
 #include "kvm_util.h"
-#include "perf_test_util.h"
+#include "memstress.h"
 #include "processor.h"
 
 struct perf_test_args perf_test_args;
diff --git a/tools/testing/selftests/kvm/lib/x86_64/perf_test_util.c b/tools/testing/selftests/kvm/lib/x86_64/memstress.c
similarity index 97%
rename from tools/testing/selftests/kvm/lib/x86_64/perf_test_util.c
rename to tools/testing/selftests/kvm/lib/x86_64/memstress.c
index 0f344a7c89c4..0bb717ac2cc5 100644
--- a/tools/testing/selftests/kvm/lib/x86_64/perf_test_util.c
+++ b/tools/testing/selftests/kvm/lib/x86_64/memstress.c
@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0
 /*
- * x86_64-specific extensions to perf_test_util.c.
+ * x86_64-specific extensions to memstress.c.
  *
  * Copyright (C) 2022, Google, Inc.
  */
@@ -11,7 +11,7 @@
 
 #include "test_util.h"
 #include "kvm_util.h"
-#include "perf_test_util.h"
+#include "memstress.h"
 #include "processor.h"
 #include "vmx.h"
 
diff --git a/tools/testing/selftests/kvm/memslot_modification_stress_test.c b/tools/testing/selftests/kvm/memslot_modification_stress_test.c
index 6ee7e1dde404..edee00eff7c4 100644
--- a/tools/testing/selftests/kvm/memslot_modification_stress_test.c
+++ b/tools/testing/selftests/kvm/memslot_modification_stress_test.c
@@ -21,7 +21,7 @@
 #include <linux/bitops.h>
 #include <linux/userfaultfd.h>
 
-#include "perf_test_util.h"
+#include "memstress.h"
 #include "processor.h"
 #include "test_util.h"
 #include "guest_modes.h"

base-commit: 1a4d88a361af4f2e91861d632c6a1fe87a9665c2
prerequisite-patch-id: 8c230105c8a2f1245dedb5b386327d98865d0bb2
prerequisite-patch-id: 9b4329037e2e880db19f3221e47d956b78acadc8
-- 
2.37.1.359.gd136c6c3e2-goog

[RFC PATCH 2/2] KVM: selftests: Rename perf_test_util symbols to memstress

[David Matlack]

Replace the perf_test_ prefix on symbol names with memstress_ to match
the new file name. Since memtress contains the same number of characters
as perf_test, there is no impact on line lengths.

While here, also update the "pta" local variables, which was short for
"perf_test_args", to "ma" for "memtest_args".

Signed-off-by: David Matlack <dmatlack@google.com>
---
 .../selftests/kvm/access_tracking_perf_test.c |  18 ++--
 .../selftests/kvm/demand_paging_test.c        |  18 ++--
 .../selftests/kvm/dirty_log_perf_test.c       |  20 ++--
 .../testing/selftests/kvm/include/memstress.h |  26 ++---
 tools/testing/selftests/kvm/lib/memstress.c   | 100 +++++++++---------
 .../selftests/kvm/lib/x86_64/memstress.c      |  32 +++---
 .../kvm/memslot_modification_stress_test.c    |  14 +--
 7 files changed, 114 insertions(+), 114 deletions(-)

diff --git a/tools/testing/selftests/kvm/access_tracking_perf_test.c b/tools/testing/selftests/kvm/access_tracking_perf_test.c
index 9c9a78ec9134..9a0fcb15e3fc 100644
--- a/tools/testing/selftests/kvm/access_tracking_perf_test.c
+++ b/tools/testing/selftests/kvm/access_tracking_perf_test.c
@@ -125,7 +125,7 @@ static void mark_page_idle(int page_idle_fd, uint64_t pfn)
 }
 
 static void mark_vcpu_memory_idle(struct kvm_vm *vm,
-				  struct perf_test_vcpu_args *vcpu_args)
+				  struct memstress_vcpu_args *vcpu_args)
 {
 	int vcpu_idx = vcpu_args->vcpu_idx;
 	uint64_t base_gva = vcpu_args->gva;
@@ -147,7 +147,7 @@ static void mark_vcpu_memory_idle(struct kvm_vm *vm,
 	TEST_ASSERT(pagemap_fd > 0, "Failed to open pagemap.");
 
 	for (page = 0; page < pages; page++) {
-		uint64_t gva = base_gva + page * perf_test_args.guest_page_size;
+		uint64_t gva = base_gva + page * memstress_args.guest_page_size;
 		uint64_t pfn = lookup_pfn(pagemap_fd, vm, gva);
 
 		if (!pfn) {
@@ -213,10 +213,10 @@ static bool spin_wait_for_next_iteration(int *current_iteration)
 	return true;
 }
 
-static void vcpu_thread_main(struct perf_test_vcpu_args *vcpu_args)
+static void vcpu_thread_main(struct memstress_vcpu_args *vcpu_args)
 {
 	struct kvm_vcpu *vcpu = vcpu_args->vcpu;
-	struct kvm_vm *vm = perf_test_args.vm;
+	struct kvm_vm *vm = memstress_args.vm;
 	int vcpu_idx = vcpu_args->vcpu_idx;
 	int current_iteration = 0;
 
@@ -272,7 +272,7 @@ static void run_iteration(struct kvm_vm *vm, int nr_vcpus, const char *descripti
 static void access_memory(struct kvm_vm *vm, int nr_vcpus,
 			  enum access_type access, const char *description)
 {
-	perf_test_set_wr_fract(vm, (access == ACCESS_READ) ? INT_MAX : 1);
+	memstress_set_wr_fract(vm, (access == ACCESS_READ) ? INT_MAX : 1);
 	iteration_work = ITERATION_ACCESS_MEMORY;
 	run_iteration(vm, nr_vcpus, description);
 }
@@ -296,10 +296,10 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 	struct kvm_vm *vm;
 	int nr_vcpus = params->nr_vcpus;
 
-	vm = perf_test_create_vm(mode, nr_vcpus, params->vcpu_memory_bytes, 1,
+	vm = memstress_create_vm(mode, nr_vcpus, params->vcpu_memory_bytes, 1,
 				 params->backing_src, !overlap_memory_access);
 
-	perf_test_start_vcpu_threads(nr_vcpus, vcpu_thread_main);
+	memstress_start_vcpu_threads(nr_vcpus, vcpu_thread_main);
 
 	pr_info("\n");
 	access_memory(vm, nr_vcpus, ACCESS_WRITE, "Populating memory");
@@ -317,8 +317,8 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 	/* Set done to signal the vCPU threads to exit */
 	done = true;
 
-	perf_test_join_vcpu_threads(nr_vcpus);
-	perf_test_destroy_vm(vm);
+	memstress_join_vcpu_threads(nr_vcpus);
+	memstress_destroy_vm(vm);
 }
 
 static void help(char *name)
diff --git a/tools/testing/selftests/kvm/demand_paging_test.c b/tools/testing/selftests/kvm/demand_paging_test.c
index 8b53ffeaaa73..35617aceb0aa 100644
--- a/tools/testing/selftests/kvm/demand_paging_test.c
+++ b/tools/testing/selftests/kvm/demand_paging_test.c
@@ -42,7 +42,7 @@ static uint64_t guest_percpu_mem_size = DEFAULT_PER_VCPU_MEM_SIZE;
 static size_t demand_paging_size;
 static char *guest_data_prototype;
 
-static void vcpu_worker(struct perf_test_vcpu_args *vcpu_args)
+static void vcpu_worker(struct memstress_vcpu_args *vcpu_args)
 {
 	struct kvm_vcpu *vcpu = vcpu_args->vcpu;
 	int vcpu_idx = vcpu_args->vcpu_idx;
@@ -285,7 +285,7 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 	struct kvm_vm *vm;
 	int r, i;
 
-	vm = perf_test_create_vm(mode, nr_vcpus, guest_percpu_mem_size, 1,
+	vm = memstress_create_vm(mode, nr_vcpus, guest_percpu_mem_size, 1,
 				 p->src_type, p->partition_vcpu_memory_access);
 
 	demand_paging_size = get_backing_src_pagesz(p->src_type);
@@ -307,11 +307,11 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 		TEST_ASSERT(pipefds, "Unable to allocate memory for pipefd");
 
 		for (i = 0; i < nr_vcpus; i++) {
-			struct perf_test_vcpu_args *vcpu_args;
+			struct memstress_vcpu_args *vcpu_args;
 			void *vcpu_hva;
 			void *vcpu_alias;
 
-			vcpu_args = &perf_test_args.vcpu_args[i];
+			vcpu_args = &memstress_args.vcpu_args[i];
 
 			/* Cache the host addresses of the region */
 			vcpu_hva = addr_gpa2hva(vm, vcpu_args->gpa);
@@ -329,17 +329,17 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 					    pipefds[i * 2], p->uffd_mode,
 					    p->uffd_delay, &uffd_args[i],
 					    vcpu_hva, vcpu_alias,
-					    vcpu_args->pages * perf_test_args.guest_page_size);
+					    vcpu_args->pages * memstress_args.guest_page_size);
 		}
 	}
 
 	pr_info("Finished creating vCPUs and starting uffd threads\n");
 
 	clock_gettime(CLOCK_MONOTONIC, &start);
-	perf_test_start_vcpu_threads(nr_vcpus, vcpu_worker);
+	memstress_start_vcpu_threads(nr_vcpus, vcpu_worker);
 	pr_info("Started all vCPUs\n");
 
-	perf_test_join_vcpu_threads(nr_vcpus);
+	memstress_join_vcpu_threads(nr_vcpus);
 	ts_diff = timespec_elapsed(start);
 	pr_info("All vCPU threads joined\n");
 
@@ -358,10 +358,10 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 	pr_info("Total guest execution time: %ld.%.9lds\n",
 		ts_diff.tv_sec, ts_diff.tv_nsec);
 	pr_info("Overall demand paging rate: %f pgs/sec\n",
-		perf_test_args.vcpu_args[0].pages * nr_vcpus /
+		memstress_args.vcpu_args[0].pages * nr_vcpus /
 		((double)ts_diff.tv_sec + (double)ts_diff.tv_nsec / 100000000.0));
 
-	perf_test_destroy_vm(vm);
+	memstress_destroy_vm(vm);
 
 	free(guest_data_prototype);
 	if (p->uffd_mode) {
diff --git a/tools/testing/selftests/kvm/dirty_log_perf_test.c b/tools/testing/selftests/kvm/dirty_log_perf_test.c
index 769ab87cadcc..1caf8ddbbc68 100644
--- a/tools/testing/selftests/kvm/dirty_log_perf_test.c
+++ b/tools/testing/selftests/kvm/dirty_log_perf_test.c
@@ -67,7 +67,7 @@ static bool host_quit;
 static int iteration;
 static int vcpu_last_completed_iteration[KVM_MAX_VCPUS];
 
-static void vcpu_worker(struct perf_test_vcpu_args *vcpu_args)
+static void vcpu_worker(struct memstress_vcpu_args *vcpu_args)
 {
 	struct kvm_vcpu *vcpu = vcpu_args->vcpu;
 	int vcpu_idx = vcpu_args->vcpu_idx;
@@ -139,7 +139,7 @@ static void toggle_dirty_logging(struct kvm_vm *vm, int slots, bool enable)
 	int i;
 
 	for (i = 0; i < slots; i++) {
-		int slot = PERF_TEST_MEM_SLOT_INDEX + i;
+		int slot = MEMSTRESS_MEM_SLOT_INDEX + i;
 		int flags = enable ? KVM_MEM_LOG_DIRTY_PAGES : 0;
 
 		vm_mem_region_set_flags(vm, slot, flags);
@@ -161,7 +161,7 @@ static void get_dirty_log(struct kvm_vm *vm, unsigned long *bitmaps[], int slots
 	int i;
 
 	for (i = 0; i < slots; i++) {
-		int slot = PERF_TEST_MEM_SLOT_INDEX + i;
+		int slot = MEMSTRESS_MEM_SLOT_INDEX + i;
 
 		kvm_vm_get_dirty_log(vm, slot, bitmaps[i]);
 	}
@@ -173,7 +173,7 @@ static void clear_dirty_log(struct kvm_vm *vm, unsigned long *bitmaps[],
 	int i;
 
 	for (i = 0; i < slots; i++) {
-		int slot = PERF_TEST_MEM_SLOT_INDEX + i;
+		int slot = MEMSTRESS_MEM_SLOT_INDEX + i;
 
 		kvm_vm_clear_dirty_log(vm, slot, bitmaps[i], 0, pages_per_slot);
 	}
@@ -221,11 +221,11 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 	struct timespec clear_dirty_log_total = (struct timespec){0};
 	int i;
 
-	vm = perf_test_create_vm(mode, nr_vcpus, guest_percpu_mem_size,
+	vm = memstress_create_vm(mode, nr_vcpus, guest_percpu_mem_size,
 				 p->slots, p->backing_src,
 				 p->partition_vcpu_memory_access);
 
-	perf_test_set_wr_fract(vm, p->wr_fract);
+	memstress_set_wr_fract(vm, p->wr_fract);
 
 	guest_num_pages = (nr_vcpus * guest_percpu_mem_size) >> vm->page_shift;
 	guest_num_pages = vm_adjust_num_guest_pages(mode, guest_num_pages);
@@ -248,7 +248,7 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 	for (i = 0; i < nr_vcpus; i++)
 		vcpu_last_completed_iteration[i] = -1;
 
-	perf_test_start_vcpu_threads(nr_vcpus, vcpu_worker);
+	memstress_start_vcpu_threads(nr_vcpus, vcpu_worker);
 
 	/* Allow the vCPUs to populate memory */
 	pr_debug("Starting iteration %d - Populating\n", iteration);
@@ -329,7 +329,7 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 	 * wait for them to exit.
 	 */
 	host_quit = true;
-	perf_test_join_vcpu_threads(nr_vcpus);
+	memstress_join_vcpu_threads(nr_vcpus);
 
 	avg = timespec_div(get_dirty_log_total, p->iterations);
 	pr_info("Get dirty log over %lu iterations took %ld.%.9lds. (Avg %ld.%.9lds/iteration)\n",
@@ -345,7 +345,7 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 
 	free_bitmaps(bitmaps, p->slots);
 	arch_cleanup_vm(vm);
-	perf_test_destroy_vm(vm);
+	memstress_destroy_vm(vm);
 }
 
 static void help(char *name)
@@ -424,7 +424,7 @@ int main(int argc, char *argv[])
 			guest_modes_cmdline(optarg);
 			break;
 		case 'n':
-			perf_test_args.nested = true;
+			memstress_args.nested = true;
 			break;
 		case 'b':
 			guest_percpu_mem_size = parse_size(optarg);
diff --git a/tools/testing/selftests/kvm/include/memstress.h b/tools/testing/selftests/kvm/include/memstress.h
index e72dfb43e456..0f0ac6bc7f28 100644
--- a/tools/testing/selftests/kvm/include/memstress.h
+++ b/tools/testing/selftests/kvm/include/memstress.h
@@ -17,9 +17,9 @@
 
 #define DEFAULT_PER_VCPU_MEM_SIZE	(1 << 30) /* 1G */
 
-#define PERF_TEST_MEM_SLOT_INDEX	1
+#define MEMSTRESS_MEM_SLOT_INDEX	1
 
-struct perf_test_vcpu_args {
+struct memstress_vcpu_args {
 	uint64_t gpa;
 	uint64_t gva;
 	uint64_t pages;
@@ -29,7 +29,7 @@ struct perf_test_vcpu_args {
 	int vcpu_idx;
 };
 
-struct perf_test_args {
+struct memstress_args {
 	struct kvm_vm *vm;
 	/* The starting address and size of the guest test region. */
 	uint64_t gpa;
@@ -40,24 +40,24 @@ struct perf_test_args {
 	/* Run vCPUs in L2 instead of L1, if the architecture supports it. */
 	bool nested;
 
-	struct perf_test_vcpu_args vcpu_args[KVM_MAX_VCPUS];
+	struct memstress_vcpu_args vcpu_args[KVM_MAX_VCPUS];
 };
 
-extern struct perf_test_args perf_test_args;
+extern struct memstress_args memstress_args;
 
-struct kvm_vm *perf_test_create_vm(enum vm_guest_mode mode, int nr_vcpus,
+struct kvm_vm *memstress_create_vm(enum vm_guest_mode mode, int nr_vcpus,
 				   uint64_t vcpu_memory_bytes, int slots,
 				   enum vm_mem_backing_src_type backing_src,
 				   bool partition_vcpu_memory_access);
-void perf_test_destroy_vm(struct kvm_vm *vm);
+void memstress_destroy_vm(struct kvm_vm *vm);
 
-void perf_test_set_wr_fract(struct kvm_vm *vm, int wr_fract);
+void memstress_set_wr_fract(struct kvm_vm *vm, int wr_fract);
 
-void perf_test_start_vcpu_threads(int vcpus, void (*vcpu_fn)(struct perf_test_vcpu_args *));
-void perf_test_join_vcpu_threads(int vcpus);
-void perf_test_guest_code(uint32_t vcpu_id);
+void memstress_start_vcpu_threads(int vcpus, void (*vcpu_fn)(struct memstress_vcpu_args *));
+void memstress_join_vcpu_threads(int vcpus);
+void memstress_guest_code(uint32_t vcpu_id);
 
-uint64_t perf_test_nested_pages(int nr_vcpus);
-void perf_test_setup_nested(struct kvm_vm *vm, int nr_vcpus, struct kvm_vcpu *vcpus[]);
+uint64_t memstress_nested_pages(int nr_vcpus);
+void memstress_setup_nested(struct kvm_vm *vm, int nr_vcpus, struct kvm_vcpu *vcpus[]);
 
 #endif /* SELFTEST_KVM_MEMSTRESS_H */
diff --git a/tools/testing/selftests/kvm/lib/memstress.c b/tools/testing/selftests/kvm/lib/memstress.c
index d3aea9e4f6a1..6611c72e9923 100644
--- a/tools/testing/selftests/kvm/lib/memstress.c
+++ b/tools/testing/selftests/kvm/lib/memstress.c
@@ -8,7 +8,7 @@
 #include "memstress.h"
 #include "processor.h"
 
-struct perf_test_args perf_test_args;
+struct memstress_args memstress_args;
 
 /*
  * Guest virtual memory offset of the testing memory slot.
@@ -31,7 +31,7 @@ struct vcpu_thread {
 static struct vcpu_thread vcpu_threads[KVM_MAX_VCPUS];
 
 /* The function run by each vCPU thread, as provided by the test. */
-static void (*vcpu_thread_fn)(struct perf_test_vcpu_args *);
+static void (*vcpu_thread_fn)(struct memstress_vcpu_args *);
 
 /* Set to true once all vCPU threads are up and running. */
 static bool all_vcpu_threads_running;
@@ -42,10 +42,10 @@ static struct kvm_vcpu *vcpus[KVM_MAX_VCPUS];
  * Continuously write to the first 8 bytes of each page in the
  * specified region.
  */
-void perf_test_guest_code(uint32_t vcpu_idx)
+void memstress_guest_code(uint32_t vcpu_idx)
 {
-	struct perf_test_args *pta = &perf_test_args;
-	struct perf_test_vcpu_args *vcpu_args = &pta->vcpu_args[vcpu_idx];
+	struct memstress_args *ma = &memstress_args;
+	struct memstress_vcpu_args *vcpu_args = &ma->vcpu_args[vcpu_idx];
 	uint64_t gva;
 	uint64_t pages;
 	int i;
@@ -58,9 +58,9 @@ void perf_test_guest_code(uint32_t vcpu_idx)
 
 	while (true) {
 		for (i = 0; i < pages; i++) {
-			uint64_t addr = gva + (i * pta->guest_page_size);
+			uint64_t addr = gva + (i * ma->guest_page_size);
 
-			if (i % pta->wr_fract == 0)
+			if (i % ma->wr_fract == 0)
 				*(uint64_t *)addr = 0x0123456789ABCDEF;
 			else
 				READ_ONCE(*(uint64_t *)addr);
@@ -70,17 +70,17 @@ void perf_test_guest_code(uint32_t vcpu_idx)
 	}
 }
 
-void perf_test_setup_vcpus(struct kvm_vm *vm, int nr_vcpus,
+void memstress_setup_vcpus(struct kvm_vm *vm, int nr_vcpus,
 			   struct kvm_vcpu *vcpus[],
 			   uint64_t vcpu_memory_bytes,
 			   bool partition_vcpu_memory_access)
 {
-	struct perf_test_args *pta = &perf_test_args;
-	struct perf_test_vcpu_args *vcpu_args;
+	struct memstress_args *ma = &memstress_args;
+	struct memstress_vcpu_args *vcpu_args;
 	int i;
 
 	for (i = 0; i < nr_vcpus; i++) {
-		vcpu_args = &pta->vcpu_args[i];
+		vcpu_args = &ma->vcpu_args[i];
 
 		vcpu_args->vcpu = vcpus[i];
 		vcpu_args->vcpu_idx = i;
@@ -89,29 +89,29 @@ void perf_test_setup_vcpus(struct kvm_vm *vm, int nr_vcpus,
 			vcpu_args->gva = guest_test_virt_mem +
 					 (i * vcpu_memory_bytes);
 			vcpu_args->pages = vcpu_memory_bytes /
-					   pta->guest_page_size;
-			vcpu_args->gpa = pta->gpa + (i * vcpu_memory_bytes);
+					   ma->guest_page_size;
+			vcpu_args->gpa = ma->gpa + (i * vcpu_memory_bytes);
 		} else {
 			vcpu_args->gva = guest_test_virt_mem;
 			vcpu_args->pages = (nr_vcpus * vcpu_memory_bytes) /
-					   pta->guest_page_size;
-			vcpu_args->gpa = pta->gpa;
+					   ma->guest_page_size;
+			vcpu_args->gpa = ma->gpa;
 		}
 
 		vcpu_args_set(vcpus[i], 1, i);
 
 		pr_debug("Added VCPU %d with test mem gpa [%lx, %lx)\n",
 			 i, vcpu_args->gpa, vcpu_args->gpa +
-			 (vcpu_args->pages * pta->guest_page_size));
+			 (vcpu_args->pages * ma->guest_page_size));
 	}
 }
 
-struct kvm_vm *perf_test_create_vm(enum vm_guest_mode mode, int nr_vcpus,
+struct kvm_vm *memstress_create_vm(enum vm_guest_mode mode, int nr_vcpus,
 				   uint64_t vcpu_memory_bytes, int slots,
 				   enum vm_mem_backing_src_type backing_src,
 				   bool partition_vcpu_memory_access)
 {
-	struct perf_test_args *pta = &perf_test_args;
+	struct memstress_args *ma = &memstress_args;
 	struct kvm_vm *vm;
 	uint64_t guest_num_pages, slot0_pages = 0;
 	uint64_t backing_src_pagesz = get_backing_src_pagesz(backing_src);
@@ -121,20 +121,20 @@ struct kvm_vm *perf_test_create_vm(enum vm_guest_mode mode, int nr_vcpus,
 	pr_info("Testing guest mode: %s\n", vm_guest_mode_string(mode));
 
 	/* By default vCPUs will write to memory. */
-	pta->wr_fract = 1;
+	ma->wr_fract = 1;
 
 	/*
 	 * Snapshot the non-huge page size.  This is used by the guest code to
 	 * access/dirty pages at the logging granularity.
 	 */
-	pta->guest_page_size = vm_guest_mode_params[mode].page_size;
+	ma->guest_page_size = vm_guest_mode_params[mode].page_size;
 
 	guest_num_pages = vm_adjust_num_guest_pages(mode,
-				(nr_vcpus * vcpu_memory_bytes) / pta->guest_page_size);
+				(nr_vcpus * vcpu_memory_bytes) / ma->guest_page_size);
 
 	TEST_ASSERT(vcpu_memory_bytes % getpagesize() == 0,
 		    "Guest memory size is not host page size aligned.");
-	TEST_ASSERT(vcpu_memory_bytes % pta->guest_page_size == 0,
+	TEST_ASSERT(vcpu_memory_bytes % ma->guest_page_size == 0,
 		    "Guest memory size is not guest page size aligned.");
 	TEST_ASSERT(guest_num_pages % slots == 0,
 		    "Guest memory cannot be evenly divided into %d slots.",
@@ -144,8 +144,8 @@ struct kvm_vm *perf_test_create_vm(enum vm_guest_mode mode, int nr_vcpus,
 	 * If using nested, allocate extra pages for the nested page tables and
 	 * in-memory data structures.
 	 */
-	if (pta->nested)
-		slot0_pages += perf_test_nested_pages(nr_vcpus);
+	if (ma->nested)
+		slot0_pages += memstress_nested_pages(nr_vcpus);
 
 	/*
 	 * Pass guest_num_pages to populate the page tables for test memory.
@@ -153,9 +153,9 @@ struct kvm_vm *perf_test_create_vm(enum vm_guest_mode mode, int nr_vcpus,
 	 * effect as KVM allows aliasing HVAs in meslots.
 	 */
 	vm = __vm_create_with_vcpus(mode, nr_vcpus, slot0_pages + guest_num_pages,
-				    perf_test_guest_code, vcpus);
+				    memstress_guest_code, vcpus);
 
-	pta->vm = vm;
+	ma->vm = vm;
 
 	/* Put the test region at the top guest physical memory. */
 	region_end_gfn = vm->max_gfn + 1;
@@ -165,8 +165,8 @@ struct kvm_vm *perf_test_create_vm(enum vm_guest_mode mode, int nr_vcpus,
 	 * When running vCPUs in L2, restrict the test region to 48 bits to
 	 * avoid needing 5-level page tables to identity map L2.
 	 */
-	if (pta->nested)
-		region_end_gfn = min(region_end_gfn, (1UL << 48) / pta->guest_page_size);
+	if (ma->nested)
+		region_end_gfn = min(region_end_gfn, (1UL << 48) / ma->guest_page_size);
 #endif
 	/*
 	 * If there should be more memory in the guest test region than there
@@ -178,63 +178,63 @@ struct kvm_vm *perf_test_create_vm(enum vm_guest_mode mode, int nr_vcpus,
 		    " nr_vcpus: %d wss: %" PRIx64 "]\n",
 		    guest_num_pages, region_end_gfn - 1, nr_vcpus, vcpu_memory_bytes);
 
-	pta->gpa = (region_end_gfn - guest_num_pages - 1) * pta->guest_page_size;
-	pta->gpa = align_down(pta->gpa, backing_src_pagesz);
+	ma->gpa = (region_end_gfn - guest_num_pages - 1) * ma->guest_page_size;
+	ma->gpa = align_down(ma->gpa, backing_src_pagesz);
 #ifdef __s390x__
 	/* Align to 1M (segment size) */
-	pta->gpa = align_down(pta->gpa, 1 << 20);
+	ma->gpa = align_down(ma->gpa, 1 << 20);
 #endif
-	pta->size = guest_num_pages * pta->guest_page_size;
+	ma->size = guest_num_pages * ma->guest_page_size;
 	pr_info("guest physical test memory: [0x%lx, 0x%lx)\n",
-		pta->gpa, pta->gpa + pta->size);
+		ma->gpa, ma->gpa + ma->size);
 
 	/* Add extra memory slots for testing */
 	for (i = 0; i < slots; i++) {
 		uint64_t region_pages = guest_num_pages / slots;
-		vm_paddr_t region_start = pta->gpa + region_pages * pta->guest_page_size * i;
+		vm_paddr_t region_start = ma->gpa + region_pages * ma->guest_page_size * i;
 
 		vm_userspace_mem_region_add(vm, backing_src, region_start,
-					    PERF_TEST_MEM_SLOT_INDEX + i,
+					    MEMSTRESS_MEM_SLOT_INDEX + i,
 					    region_pages, 0);
 	}
 
 	/* Do mapping for the demand paging memory slot */
-	virt_map(vm, guest_test_virt_mem, pta->gpa, guest_num_pages);
+	virt_map(vm, guest_test_virt_mem, ma->gpa, guest_num_pages);
 
-	perf_test_setup_vcpus(vm, nr_vcpus, vcpus, vcpu_memory_bytes,
+	memstress_setup_vcpus(vm, nr_vcpus, vcpus, vcpu_memory_bytes,
 			      partition_vcpu_memory_access);
 
-	if (pta->nested) {
+	if (ma->nested) {
 		pr_info("Configuring vCPUs to run in L2 (nested).\n");
-		perf_test_setup_nested(vm, nr_vcpus, vcpus);
+		memstress_setup_nested(vm, nr_vcpus, vcpus);
 	}
 
 	ucall_init(vm, NULL);
 
 	/* Export the shared variables to the guest. */
-	sync_global_to_guest(vm, perf_test_args);
+	sync_global_to_guest(vm, memstress_args);
 
 	return vm;
 }
 
-void perf_test_destroy_vm(struct kvm_vm *vm)
+void memstress_destroy_vm(struct kvm_vm *vm)
 {
 	ucall_uninit(vm);
 	kvm_vm_free(vm);
 }
 
-void perf_test_set_wr_fract(struct kvm_vm *vm, int wr_fract)
+void memstress_set_wr_fract(struct kvm_vm *vm, int wr_fract)
 {
-	perf_test_args.wr_fract = wr_fract;
-	sync_global_to_guest(vm, perf_test_args);
+	memstress_args.wr_fract = wr_fract;
+	sync_global_to_guest(vm, memstress_args);
 }
 
-uint64_t __weak perf_test_nested_pages(int nr_vcpus)
+uint64_t __weak memstress_nested_pages(int nr_vcpus)
 {
 	return 0;
 }
 
-void __weak perf_test_setup_nested(struct kvm_vm *vm, int nr_vcpus, struct kvm_vcpu **vcpus)
+void __weak memstress_setup_nested(struct kvm_vm *vm, int nr_vcpus, struct kvm_vcpu **vcpus)
 {
 	pr_info("%s() not support on this architecture, skipping.\n", __func__);
 	exit(KSFT_SKIP);
@@ -255,13 +255,13 @@ static void *vcpu_thread_main(void *data)
 	while (!READ_ONCE(all_vcpu_threads_running))
 		;
 
-	vcpu_thread_fn(&perf_test_args.vcpu_args[vcpu->vcpu_idx]);
+	vcpu_thread_fn(&memstress_args.vcpu_args[vcpu->vcpu_idx]);
 
 	return NULL;
 }
 
-void perf_test_start_vcpu_threads(int nr_vcpus,
-				  void (*vcpu_fn)(struct perf_test_vcpu_args *))
+void memstress_start_vcpu_threads(int nr_vcpus,
+				  void (*vcpu_fn)(struct memstress_vcpu_args *))
 {
 	int i;
 
@@ -285,7 +285,7 @@ void perf_test_start_vcpu_threads(int nr_vcpus,
 	WRITE_ONCE(all_vcpu_threads_running, true);
 }
 
-void perf_test_join_vcpu_threads(int nr_vcpus)
+void memstress_join_vcpu_threads(int nr_vcpus)
 {
 	int i;
 
diff --git a/tools/testing/selftests/kvm/lib/x86_64/memstress.c b/tools/testing/selftests/kvm/lib/x86_64/memstress.c
index 0bb717ac2cc5..2b3b47e4a973 100644
--- a/tools/testing/selftests/kvm/lib/x86_64/memstress.c
+++ b/tools/testing/selftests/kvm/lib/x86_64/memstress.c
@@ -15,21 +15,21 @@
 #include "processor.h"
 #include "vmx.h"
 
-void perf_test_l2_guest_code(uint64_t vcpu_id)
+void memstress_l2_guest_code(uint64_t vcpu_id)
 {
-	perf_test_guest_code(vcpu_id);
+	memstress_guest_code(vcpu_id);
 	vmcall();
 }
 
-extern char perf_test_l2_guest_entry[];
+extern char memstress_l2_guest_entry[];
 __asm__(
-"perf_test_l2_guest_entry:"
+"memstress_l2_guest_entry:"
 "	mov (%rsp), %rdi;"
-"	call perf_test_l2_guest_code;"
+"	call memstress_l2_guest_code;"
 "	ud2;"
 );
 
-static void perf_test_l1_guest_code(struct vmx_pages *vmx, uint64_t vcpu_id)
+static void memstress_l1_guest_code(struct vmx_pages *vmx, uint64_t vcpu_id)
 {
 #define L2_GUEST_STACK_SIZE 64
 	unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE];
@@ -42,14 +42,14 @@ static void perf_test_l1_guest_code(struct vmx_pages *vmx, uint64_t vcpu_id)
 
 	rsp = &l2_guest_stack[L2_GUEST_STACK_SIZE - 1];
 	*rsp = vcpu_id;
-	prepare_vmcs(vmx, perf_test_l2_guest_entry, rsp);
+	prepare_vmcs(vmx, memstress_l2_guest_entry, rsp);
 
 	GUEST_ASSERT(!vmlaunch());
 	GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_VMCALL);
 	GUEST_DONE();
 }
 
-uint64_t perf_test_nested_pages(int nr_vcpus)
+uint64_t memstress_nested_pages(int nr_vcpus)
 {
 	/*
 	 * 513 page tables is enough to identity-map 256 TiB of L2 with 1G
@@ -59,7 +59,7 @@ uint64_t perf_test_nested_pages(int nr_vcpus)
 	return 513 + 10 * nr_vcpus;
 }
 
-void perf_test_setup_ept(struct vmx_pages *vmx, struct kvm_vm *vm)
+void memstress_setup_ept(struct vmx_pages *vmx, struct kvm_vm *vm)
 {
 	uint64_t start, end;
 
@@ -72,12 +72,12 @@ void perf_test_setup_ept(struct vmx_pages *vmx, struct kvm_vm *vm)
 	 */
 	nested_identity_map_1g(vmx, vm, 0, 0x100000000ULL);
 
-	start = align_down(perf_test_args.gpa, PG_SIZE_1G);
-	end = align_up(perf_test_args.gpa + perf_test_args.size, PG_SIZE_1G);
+	start = align_down(memstress_args.gpa, PG_SIZE_1G);
+	end = align_up(memstress_args.gpa + memstress_args.size, PG_SIZE_1G);
 	nested_identity_map_1g(vmx, vm, start, end - start);
 }
 
-void perf_test_setup_nested(struct kvm_vm *vm, int nr_vcpus, struct kvm_vcpu *vcpus[])
+void memstress_setup_nested(struct kvm_vm *vm, int nr_vcpus, struct kvm_vcpu *vcpus[])
 {
 	struct vmx_pages *vmx, *vmx0 = NULL;
 	struct kvm_regs regs;
@@ -90,7 +90,7 @@ void perf_test_setup_nested(struct kvm_vm *vm, int nr_vcpus, struct kvm_vcpu *vc
 		vmx = vcpu_alloc_vmx(vm, &vmx_gva);
 
 		if (vcpu_id == 0) {
-			perf_test_setup_ept(vmx, vm);
+			memstress_setup_ept(vmx, vm);
 			vmx0 = vmx;
 		} else {
 			/* Share the same EPT table across all vCPUs. */
@@ -100,11 +100,11 @@ void perf_test_setup_nested(struct kvm_vm *vm, int nr_vcpus, struct kvm_vcpu *vc
 		}
 
 		/*
-		 * Override the vCPU to run perf_test_l1_guest_code() which will
-		 * bounce it into L2 before calling perf_test_guest_code().
+		 * Override the vCPU to run memstress_l1_guest_code() which will
+		 * bounce it into L2 before calling memstress_guest_code().
 		 */
 		vcpu_regs_get(vcpus[vcpu_id], &regs);
-		regs.rip = (unsigned long) perf_test_l1_guest_code;
+		regs.rip = (unsigned long) memstress_l1_guest_code;
 		vcpu_regs_set(vcpus[vcpu_id], &regs);
 		vcpu_args_set(vcpus[vcpu_id], 2, vmx_gva, vcpu_id);
 	}
diff --git a/tools/testing/selftests/kvm/memslot_modification_stress_test.c b/tools/testing/selftests/kvm/memslot_modification_stress_test.c
index edee00eff7c4..dd989867fb44 100644
--- a/tools/testing/selftests/kvm/memslot_modification_stress_test.c
+++ b/tools/testing/selftests/kvm/memslot_modification_stress_test.c
@@ -36,7 +36,7 @@ static uint64_t guest_percpu_mem_size = DEFAULT_PER_VCPU_MEM_SIZE;
 
 static bool run_vcpus = true;
 
-static void vcpu_worker(struct perf_test_vcpu_args *vcpu_args)
+static void vcpu_worker(struct memstress_vcpu_args *vcpu_args)
 {
 	struct kvm_vcpu *vcpu = vcpu_args->vcpu;
 	struct kvm_run *run;
@@ -72,10 +72,10 @@ static void add_remove_memslot(struct kvm_vm *vm, useconds_t delay,
 	int i;
 
 	/*
-	 * Add the dummy memslot just below the perf_test_util memslot, which is
+	 * Add the dummy memslot just below the memstress memslot, which is
 	 * at the top of the guest physical address space.
 	 */
-	gpa = perf_test_args.gpa - pages * vm->page_size;
+	gpa = memstress_args.gpa - pages * vm->page_size;
 
 	for (i = 0; i < nr_modifications; i++) {
 		usleep(delay);
@@ -97,13 +97,13 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 	struct test_params *p = arg;
 	struct kvm_vm *vm;
 
-	vm = perf_test_create_vm(mode, nr_vcpus, guest_percpu_mem_size, 1,
+	vm = memstress_create_vm(mode, nr_vcpus, guest_percpu_mem_size, 1,
 				 VM_MEM_SRC_ANONYMOUS,
 				 p->partition_vcpu_memory_access);
 
 	pr_info("Finished creating vCPUs\n");
 
-	perf_test_start_vcpu_threads(nr_vcpus, vcpu_worker);
+	memstress_start_vcpu_threads(nr_vcpus, vcpu_worker);
 
 	pr_info("Started all vCPUs\n");
 
@@ -112,10 +112,10 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 
 	run_vcpus = false;
 
-	perf_test_join_vcpu_threads(nr_vcpus);
+	memstress_join_vcpu_threads(nr_vcpus);
 	pr_info("All vCPU threads joined\n");
 
-	perf_test_destroy_vm(vm);
+	memstress_destroy_vm(vm);
 }
 
 static void help(char *name)
-- 
2.37.1.359.gd136c6c3e2-goog

Re: [RFC PATCH 0/2] KVM: selftests: Rename perf_test_util to memstress

[Andrew Jones]

On Mon, Jul 25, 2022 at 04:35:37PM +0000, David Matlack wrote:
> This series renames the perf_test_util to memstress. patch 1 renames the files
> perf_test_util.[ch] to memstress.[ch], and patch 2 replaces the perf_test_
> prefix on symbols with memstress_.
> 
> The reason for this rename, as with any rename, is to improve readability.
> perf_test_util is too generic and does not describe at all what the library
> does, other than being used for perf tests.
> 
> I considered a lot of different names (naming is hard) and eventually settled
> on memstress for a few reasons:
> 
>  - "memstress" better describes the functionality proveded by this library,
>    which is to run a VM that reads/writes to memory from all vCPUs in parallel
>    (i.e. stressing VM memory).
> 
>  - "memstress" contains the same number of characters as "perf_test", making
>    it a drop in replacement in symbols wihout changing line lengths.
> 
>  - The lack of underscore between "mem" and "stress" makes it clear "memstress"
>    is a noun, avoiding confusion in function names.

Naming is hard, acking rename patches that have good justifications is
easy.  For the series,

Acked-by: Andrew Jones <andrew.jones@linux.dev>

Re: [RFC PATCH 0/2] KVM: selftests: Rename perf_test_util to memstress

[Sean Christopherson]

On Mon, Jul 25, 2022, David Matlack wrote:
> This series renames the perf_test_util to memstress. patch 1 renames the files
> perf_test_util.[ch] to memstress.[ch], and patch 2 replaces the perf_test_
> prefix on symbols with memstress_.
> 
> The reason for this rename, as with any rename, is to improve readability.
> perf_test_util is too generic and does not describe at all what the library
> does, other than being used for perf tests.
> 
> I considered a lot of different names (naming is hard) and eventually settled
> on memstress for a few reasons:
> 
>  - "memstress" better describes the functionality proveded by this library,
>    which is to run a VM that reads/writes to memory from all vCPUs in parallel
>    (i.e. stressing VM memory).

Hmm, but the purpose of the library isn't to stress VM memory so much as it is to
stress KVM's MMU.  And typically "stress" tests just hammer a resource to try and
make it fail, whereas measuring performance is one of the main 

In other words, IMO it would be nice to keep "perf" in there somehwere.

Maybe mmu_perf or something along those lines?  I wouldn't worry too much about
changing the number of chars, the churn wouldn't be thaaat bad.

Re: [RFC PATCH 0/2] KVM: selftests: Rename perf_test_util to memstress

[David Matlack]

On Mon, Jul 25, 2022 at 3:45 PM Sean Christopherson <seanjc@google.com> wrote:
>
> On Mon, Jul 25, 2022, David Matlack wrote:
> > This series renames the perf_test_util to memstress. patch 1 renames the files
> > perf_test_util.[ch] to memstress.[ch], and patch 2 replaces the perf_test_
> > prefix on symbols with memstress_.
> >
> > The reason for this rename, as with any rename, is to improve readability.
> > perf_test_util is too generic and does not describe at all what the library
> > does, other than being used for perf tests.
> >
> > I considered a lot of different names (naming is hard) and eventually settled
> > on memstress for a few reasons:
> >
> >  - "memstress" better describes the functionality proveded by this library,
> >    which is to run a VM that reads/writes to memory from all vCPUs in parallel
> >    (i.e. stressing VM memory).
>
> Hmm, but the purpose of the library isn't to stress VM memory so much as it is to
> stress KVM's MMU. And typically "stress" tests just hammer a resource to try and
> make it fail, whereas measuring performance is one of the main
>
> In other words, IMO it would be nice to keep "perf" in there somehwere.

The reasons I leaned toward "stress" rather than "perf" is that this
library itself does not measure performance (it's just a workload) and
it's not always used for performance tests (e.g.
memslot_modification_stress_test.c).

>
> Maybe mmu_perf or something along those lines?

How about "memperf"? "mmu_perf" makes me think it'd be explicitly
measuring the performance of MMU operations.

Another contender was "memstorm", but I thought it might be too cute.

> I wouldn't worry too much about
> changing the number of chars, the churn wouldn't be thaaat bad.

Heh. The line lengths were getting long when I played with
"memory_stress" :). But yeah it's not really that much churn.

Re: [RFC PATCH 0/2] KVM: selftests: Rename perf_test_util to memstress

[Sean Christopherson]

On Tue, Jul 26, 2022, David Matlack wrote:
> On Mon, Jul 25, 2022 at 3:45 PM Sean Christopherson <seanjc@google.com> wrote:
> >
> > On Mon, Jul 25, 2022, David Matlack wrote:
> > > This series renames the perf_test_util to memstress. patch 1 renames the files
> > > perf_test_util.[ch] to memstress.[ch], and patch 2 replaces the perf_test_
> > > prefix on symbols with memstress_.
> > >
> > > The reason for this rename, as with any rename, is to improve readability.
> > > perf_test_util is too generic and does not describe at all what the library
> > > does, other than being used for perf tests.
> > >
> > > I considered a lot of different names (naming is hard) and eventually settled
> > > on memstress for a few reasons:
> > >
> > >  - "memstress" better describes the functionality proveded by this library,
> > >    which is to run a VM that reads/writes to memory from all vCPUs in parallel
> > >    (i.e. stressing VM memory).
> >
> > Hmm, but the purpose of the library isn't to stress VM memory so much as it is to
> > stress KVM's MMU. And typically "stress" tests just hammer a resource to try and
> > make it fail, whereas measuring performance is one of the main
> >
> > In other words, IMO it would be nice to keep "perf" in there somehwere.
> 
> The reasons I leaned toward "stress" rather than "perf" is that this
> library itself does not measure performance (it's just a workload) and
> it's not always used for performance tests (e.g.
> memslot_modification_stress_test.c).

Yeah, I don't disagree on any point, it's purely that memstress makes me think of
memtest (the pre-boot test that blasts memory with patterns to detect bad DRAM).

> > Maybe mmu_perf or something along those lines?
> 
> How about "memperf"? "mmu_perf" makes me think it'd be explicitly
> measuring the performance of MMU operations.

Let's go with your original "memstress".  I like how it looks in code, and once I
get past the initial "memtest" association, it's a good fit.

> Another contender was "memstorm", but I thought it might be too cute.

Heh.  mem_minions?  Then we can have "mm_args" and really confuse everyone.