diff mbox series

[RESEND,v7,09/10] selftests/mm/cow: Generalize do_run_with_thp() helper

Message ID 20231122162950.3854897-10-ryan.roberts@arm.com
State New
Headers
Series Small-sized THP for anonymous memory |

Commit Message

Ryan Roberts Nov. 22, 2023, 4:29 p.m. UTC 
  do_run_with_thp() prepares (PMD-sized) THP memory into different states
before running tests. With the introduction of small-sized THP, we would
like to reuse this logic to also test those smaller THP sizes. So let's
add a size parameter which tells the function what size THP it should
operate on.

A separate commit will utilize this change to add new tests for
small-sized THP, where available.

Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
---
 tools/testing/selftests/mm/cow.c | 146 +++++++++++++++++--------------
 1 file changed, 79 insertions(+), 67 deletions(-)

--
2.25.1

Comments

David Hildenbrand Nov. 24, 2023, 5:48 p.m. UTC | #1 
On 22.11.23 17:29, Ryan Roberts wrote:
> do_run_with_thp() prepares (PMD-sized) THP memory into different states
> before running tests. With the introduction of small-sized THP, we would
> like to reuse this logic to also test those smaller THP sizes. So let's
> add a size parameter which tells the function what size THP it should
> operate on.
> 
> A separate commit will utilize this change to add new tests for
> small-sized THP, where available.
> 
> Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
> ---
>   tools/testing/selftests/mm/cow.c | 146 +++++++++++++++++--------------
>   1 file changed, 79 insertions(+), 67 deletions(-)
> 
> diff --git a/tools/testing/selftests/mm/cow.c b/tools/testing/selftests/mm/cow.c
> index 7324ce5363c0..d03c453cfd5c 100644
> --- a/tools/testing/selftests/mm/cow.c
> +++ b/tools/testing/selftests/mm/cow.c
> @@ -32,7 +32,7 @@
> 
>   static size_t pagesize;
>   static int pagemap_fd;
> -static size_t thpsize;
> +static size_t pmdsize;
>   static int nr_hugetlbsizes;
>   static size_t hugetlbsizes[10];
>   static int gup_fd;
> @@ -734,14 +734,14 @@ enum thp_run {
>   	THP_RUN_PARTIAL_SHARED,
>   };
> 
> -static void do_run_with_thp(test_fn fn, enum thp_run thp_run)
> +static void do_run_with_thp(test_fn fn, enum thp_run thp_run, size_t size)

Nit: can we still call it "thpsize" in this function? That makes it 
clearer IMHO and avoids most renaming.

>   {
>   	char *mem, *mmap_mem, *tmp, *mremap_mem = MAP_FAILED;
> -	size_t size, mmap_size, mremap_size;
> +	size_t mmap_size, mremap_size;
>   	int ret;
> 
> -	/* For alignment purposes, we need twice the thp size. */
> -	mmap_size = 2 * thpsize;
> +	/* For alignment purposes, we need twice the requested size. */
> +	mmap_size = 2 * size;
>   	mmap_mem = mmap(NULL, mmap_size, PROT_READ | PROT_WRITE,
>   			MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
>   	if (mmap_mem == MAP_FAILED) {
> @@ -749,36 +749,40 @@ static void do_run_with_thp(test_fn fn, enum thp_run thp_run)
>   		return;
>   	}
> 
> -	/* We need a THP-aligned memory area. */
> -	mem = (char *)(((uintptr_t)mmap_mem + thpsize) & ~(thpsize - 1));
> +	/* We need to naturally align the memory area. */
> +	mem = (char *)(((uintptr_t)mmap_mem + size) & ~(size - 1));
> 
> -	ret = madvise(mem, thpsize, MADV_HUGEPAGE);
> +	ret = madvise(mem, size, MADV_HUGEPAGE);
>   	if (ret) {
>   		ksft_test_result_fail("MADV_HUGEPAGE failed\n");
>   		goto munmap;
>   	}
> 
>   	/*
> -	 * Try to populate a THP. Touch the first sub-page and test if we get
> -	 * another sub-page populated automatically.
> +	 * Try to populate a THP. Touch the first sub-page and test if
> +	 * we get the last sub-page populated automatically.
>   	 */
>   	mem[0] = 0;
> -	if (!pagemap_is_populated(pagemap_fd, mem + pagesize)) {
> +	if (!pagemap_is_populated(pagemap_fd, mem + size - pagesize)) {
>   		ksft_test_result_skip("Did not get a THP populated\n");
>   		goto munmap;
>   	}

Yes! I have a patch lying around here that does that same. :)

I guess there is no need to set MADV_NOHUGEPAGE on the remainder of the 
mmap'ed are:

Assume we want a 64KiB thp. We mmap'ed 128KiB. If we get a reasonably 
aligned area, we might populate a 128KiB THP.

But I assume the MADV_HUGEPAGE will in all configurations properly 
create a separate 64KiB VMA and we'll never get 128 KiB populated. So 
this should work reliably.

> -	memset(mem, 0, thpsize);
> +	memset(mem, 0, size);
> 
> -	size = thpsize;
>   	switch (thp_run) {
>   	case THP_RUN_PMD:
>   	case THP_RUN_PMD_SWAPOUT:
> +		if (size != pmdsize) {
> +			ksft_test_result_fail("test bug: can't PMD-map size\n");
> +			goto munmap;
> +		}

Maybe rather "assert()" because that's a real BUG in the test?

[...]

> +	pmdsize = read_pmd_pagesize();
> +	if (pmdsize)
> +		ksft_print_msg("[INFO] detected PMD-mapped THP size: %zu KiB\n",

Maybe simply: "detected PMD size". Zes, we read it via the THP 
interface, but that shouldn't matter much.
Ryan Roberts Nov. 27, 2023, 10:48 a.m. UTC | #2 
On 24/11/2023 17:48, David Hildenbrand wrote:
> On 22.11.23 17:29, Ryan Roberts wrote:
>> do_run_with_thp() prepares (PMD-sized) THP memory into different states
>> before running tests. With the introduction of small-sized THP, we would
>> like to reuse this logic to also test those smaller THP sizes. So let's
>> add a size parameter which tells the function what size THP it should
>> operate on.
>>
>> A separate commit will utilize this change to add new tests for
>> small-sized THP, where available.
>>
>> Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
>> ---
>>   tools/testing/selftests/mm/cow.c | 146 +++++++++++++++++--------------
>>   1 file changed, 79 insertions(+), 67 deletions(-)
>>
>> diff --git a/tools/testing/selftests/mm/cow.c b/tools/testing/selftests/mm/cow.c
>> index 7324ce5363c0..d03c453cfd5c 100644
>> --- a/tools/testing/selftests/mm/cow.c
>> +++ b/tools/testing/selftests/mm/cow.c
>> @@ -32,7 +32,7 @@
>>
>>   static size_t pagesize;
>>   static int pagemap_fd;
>> -static size_t thpsize;
>> +static size_t pmdsize;
>>   static int nr_hugetlbsizes;
>>   static size_t hugetlbsizes[10];
>>   static int gup_fd;
>> @@ -734,14 +734,14 @@ enum thp_run {
>>       THP_RUN_PARTIAL_SHARED,
>>   };
>>
>> -static void do_run_with_thp(test_fn fn, enum thp_run thp_run)
>> +static void do_run_with_thp(test_fn fn, enum thp_run thp_run, size_t size)
> 
> Nit: can we still call it "thpsize" in this function? That makes it clearer IMHO
> and avoids most renaming.

Yep no problem. Will fix in next version.

> 
>>   {
>>       char *mem, *mmap_mem, *tmp, *mremap_mem = MAP_FAILED;
>> -    size_t size, mmap_size, mremap_size;
>> +    size_t mmap_size, mremap_size;
>>       int ret;
>>
>> -    /* For alignment purposes, we need twice the thp size. */
>> -    mmap_size = 2 * thpsize;
>> +    /* For alignment purposes, we need twice the requested size. */
>> +    mmap_size = 2 * size;
>>       mmap_mem = mmap(NULL, mmap_size, PROT_READ | PROT_WRITE,
>>               MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
>>       if (mmap_mem == MAP_FAILED) {
>> @@ -749,36 +749,40 @@ static void do_run_with_thp(test_fn fn, enum thp_run
>> thp_run)
>>           return;
>>       }
>>
>> -    /* We need a THP-aligned memory area. */
>> -    mem = (char *)(((uintptr_t)mmap_mem + thpsize) & ~(thpsize - 1));
>> +    /* We need to naturally align the memory area. */
>> +    mem = (char *)(((uintptr_t)mmap_mem + size) & ~(size - 1));
>>
>> -    ret = madvise(mem, thpsize, MADV_HUGEPAGE);
>> +    ret = madvise(mem, size, MADV_HUGEPAGE);
>>       if (ret) {
>>           ksft_test_result_fail("MADV_HUGEPAGE failed\n");
>>           goto munmap;
>>       }
>>
>>       /*
>> -     * Try to populate a THP. Touch the first sub-page and test if we get
>> -     * another sub-page populated automatically.
>> +     * Try to populate a THP. Touch the first sub-page and test if
>> +     * we get the last sub-page populated automatically.
>>        */
>>       mem[0] = 0;
>> -    if (!pagemap_is_populated(pagemap_fd, mem + pagesize)) {
>> +    if (!pagemap_is_populated(pagemap_fd, mem + size - pagesize)) {
>>           ksft_test_result_skip("Did not get a THP populated\n");
>>           goto munmap;
>>       }
> 
> Yes! I have a patch lying around here that does that same. :)
> 
> I guess there is no need to set MADV_NOHUGEPAGE on the remainder of the mmap'ed
> are:
> 
> Assume we want a 64KiB thp. We mmap'ed 128KiB. If we get a reasonably aligned
> area, we might populate a 128KiB THP.
> 
> But I assume the MADV_HUGEPAGE will in all configurations properly create a
> separate 64KiB VMA and we'll never get 128 KiB populated. So this should work
> reliably.

Yes agreed. And also, we explicitly only enable a single THP size at a time so
should only allocate a THP of the expected size. Perhaps we should mark the
whole mmap area with MADV_HUGEPAGE since that will serve as a test that we only
get the smaller size we configured?

> 
>> -    memset(mem, 0, thpsize);
>> +    memset(mem, 0, size);
>>
>> -    size = thpsize;
>>       switch (thp_run) {
>>       case THP_RUN_PMD:
>>       case THP_RUN_PMD_SWAPOUT:
>> +        if (size != pmdsize) {
>> +            ksft_test_result_fail("test bug: can't PMD-map size\n");
>> +            goto munmap;
>> +        }
> 
> Maybe rather "assert()" because that's a real BUG in the test?

Yep will do.

> 
> [...]
> 
>> +    pmdsize = read_pmd_pagesize();
>> +    if (pmdsize)
>> +        ksft_print_msg("[INFO] detected PMD-mapped THP size: %zu KiB\n",
> 
> Maybe simply: "detected PMD size". Zes, we read it via the THP interface, but
> that shouldn't matter much.

Err, just want to clarify what you are suggesting. With the current patch you
will see something like:

[INFO] detected PMD-mapped THP size: 2048 KiB
[INFO] detected small-sized THP size: 64 KiB
[INFO] detected small-sized THP size: 128 KiB
...
[INFO] detected small-sized THP size: 1024 KiB


Are you suggesting something like this:

[INFO] detected PMD size: 2048 KiB
[INFO] detected THP size: 64 KiB
[INFO] detected THP size: 128 KiB
...
[INFO] detected THP size: 2048 KiB


>
David Hildenbrand Nov. 27, 2023, 1:59 p.m. UTC | #3 
>>
>>> +    pmdsize = read_pmd_pagesize();
>>> +    if (pmdsize)
>>> +        ksft_print_msg("[INFO] detected PMD-mapped THP size: %zu KiB\n",
>>
>> Maybe simply: "detected PMD size". Zes, we read it via the THP interface, but
>> that shouldn't matter much.
> 
> Err, just want to clarify what you are suggesting. With the current patch you
> will see something like:

Not with this patch, but with the other ones, yes :)

> 
> [INFO] detected PMD-mapped THP size: 2048 KiB
> [INFO] detected small-sized THP size: 64 KiB
> [INFO] detected small-sized THP size: 128 KiB
> ...
> [INFO] detected small-sized THP size: 1024 KiB
> 
> 
> Are you suggesting something like this:
> 
> [INFO] detected PMD size: 2048 KiB
> [INFO] detected THP size: 64 KiB
> [INFO] detected THP size: 128 KiB
> ...
> [INFO] detected THP size: 2048 KiB
> 

Yes. If you'd detect that 2M is actually disabled, you could still log 
the PMD size only.

So for this patch only as a preparation

[INFO] detected PMD size: 2048 KiB
[INFO] detected THP size: 2048 KiB

Just a thought.
Ryan Roberts Nov. 27, 2023, 2:11 p.m. UTC | #4 
On 27/11/2023 13:59, David Hildenbrand wrote:
>>>
>>>> +    pmdsize = read_pmd_pagesize();
>>>> +    if (pmdsize)
>>>> +        ksft_print_msg("[INFO] detected PMD-mapped THP size: %zu KiB\n",
>>>
>>> Maybe simply: "detected PMD size". Zes, we read it via the THP interface, but
>>> that shouldn't matter much.
>>
>> Err, just want to clarify what you are suggesting. With the current patch you
>> will see something like:
> 
> Not with this patch, but with the other ones, yes :)

Yep, we are on the same page (folio)...

> 
>>
>> [INFO] detected PMD-mapped THP size: 2048 KiB
>> [INFO] detected small-sized THP size: 64 KiB
>> [INFO] detected small-sized THP size: 128 KiB
>> ...
>> [INFO] detected small-sized THP size: 1024 KiB
>>
>>
>> Are you suggesting something like this:
>>
>> [INFO] detected PMD size: 2048 KiB
>> [INFO] detected THP size: 64 KiB
>> [INFO] detected THP size: 128 KiB
>> ...
>> [INFO] detected THP size: 2048 KiB
>>
> 
> Yes. If you'd detect that 2M is actually disabled, you could still log the PMD
> size only.

Note that in the final patch, where I test the other THP sizes, I'm not
detecting which sizes the sysadmin has enabled, I'm detecting the set of sizes
that can be enabled, then explicitly enabling the size (exclusively) when I test
it. So there is no chance of reading PMD size but not having 2M THP. Minor point
though.

> 
> So for this patch only as a preparation
> 
> [INFO] detected PMD size: 2048 KiB
> [INFO] detected THP size: 2048 KiB
> 
> Just a thought.

Yep this is exactly how I've just reworked it.
David Hildenbrand Nov. 27, 2023, 2:17 p.m. UTC | #5 
On 27.11.23 15:11, Ryan Roberts wrote:
> On 27/11/2023 13:59, David Hildenbrand wrote:
>>>>
>>>>> +    pmdsize = read_pmd_pagesize();
>>>>> +    if (pmdsize)
>>>>> +        ksft_print_msg("[INFO] detected PMD-mapped THP size: %zu KiB\n",
>>>>
>>>> Maybe simply: "detected PMD size". Zes, we read it via the THP interface, but
>>>> that shouldn't matter much.
>>>
>>> Err, just want to clarify what you are suggesting. With the current patch you
>>> will see something like:
>>
>> Not with this patch, but with the other ones, yes :)
> 
> Yep, we are on the same page (folio)...
> 
>>
>>>
>>> [INFO] detected PMD-mapped THP size: 2048 KiB
>>> [INFO] detected small-sized THP size: 64 KiB
>>> [INFO] detected small-sized THP size: 128 KiB
>>> ...
>>> [INFO] detected small-sized THP size: 1024 KiB
>>>
>>>
>>> Are you suggesting something like this:
>>>
>>> [INFO] detected PMD size: 2048 KiB
>>> [INFO] detected THP size: 64 KiB
>>> [INFO] detected THP size: 128 KiB
>>> ...
>>> [INFO] detected THP size: 2048 KiB
>>>
>>
>> Yes. If you'd detect that 2M is actually disabled, you could still log the PMD
>> size only.
> 
> Note that in the final patch, where I test the other THP sizes, I'm not
> detecting which sizes the sysadmin has enabled, I'm detecting the set of sizes
> that can be enabled, then explicitly enabling the size (exclusively) when I test
> it. So there is no chance of reading PMD size but not having 2M THP. Minor point
> though.

Ah, makes sense, I missed that and thought we'd check if that size is 
actually possible.
diff mbox series

Patch

diff --git a/tools/testing/selftests/mm/cow.c b/tools/testing/selftests/mm/cow.c
index 7324ce5363c0..d03c453cfd5c 100644
--- a/tools/testing/selftests/mm/cow.c
+++ b/tools/testing/selftests/mm/cow.c
@@ -32,7 +32,7 @@ 

 static size_t pagesize;
 static int pagemap_fd;
-static size_t thpsize;
+static size_t pmdsize;
 static int nr_hugetlbsizes;
 static size_t hugetlbsizes[10];
 static int gup_fd;
@@ -734,14 +734,14 @@  enum thp_run {
 	THP_RUN_PARTIAL_SHARED,
 };

-static void do_run_with_thp(test_fn fn, enum thp_run thp_run)
+static void do_run_with_thp(test_fn fn, enum thp_run thp_run, size_t size)
 {
 	char *mem, *mmap_mem, *tmp, *mremap_mem = MAP_FAILED;
-	size_t size, mmap_size, mremap_size;
+	size_t mmap_size, mremap_size;
 	int ret;

-	/* For alignment purposes, we need twice the thp size. */
-	mmap_size = 2 * thpsize;
+	/* For alignment purposes, we need twice the requested size. */
+	mmap_size = 2 * size;
 	mmap_mem = mmap(NULL, mmap_size, PROT_READ | PROT_WRITE,
 			MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 	if (mmap_mem == MAP_FAILED) {
@@ -749,36 +749,40 @@  static void do_run_with_thp(test_fn fn, enum thp_run thp_run)
 		return;
 	}

-	/* We need a THP-aligned memory area. */
-	mem = (char *)(((uintptr_t)mmap_mem + thpsize) & ~(thpsize - 1));
+	/* We need to naturally align the memory area. */
+	mem = (char *)(((uintptr_t)mmap_mem + size) & ~(size - 1));

-	ret = madvise(mem, thpsize, MADV_HUGEPAGE);
+	ret = madvise(mem, size, MADV_HUGEPAGE);
 	if (ret) {
 		ksft_test_result_fail("MADV_HUGEPAGE failed\n");
 		goto munmap;
 	}

 	/*
-	 * Try to populate a THP. Touch the first sub-page and test if we get
-	 * another sub-page populated automatically.
+	 * Try to populate a THP. Touch the first sub-page and test if
+	 * we get the last sub-page populated automatically.
 	 */
 	mem[0] = 0;
-	if (!pagemap_is_populated(pagemap_fd, mem + pagesize)) {
+	if (!pagemap_is_populated(pagemap_fd, mem + size - pagesize)) {
 		ksft_test_result_skip("Did not get a THP populated\n");
 		goto munmap;
 	}
-	memset(mem, 0, thpsize);
+	memset(mem, 0, size);

-	size = thpsize;
 	switch (thp_run) {
 	case THP_RUN_PMD:
 	case THP_RUN_PMD_SWAPOUT:
+		if (size != pmdsize) {
+			ksft_test_result_fail("test bug: can't PMD-map size\n");
+			goto munmap;
+		}
 		break;
 	case THP_RUN_PTE:
 	case THP_RUN_PTE_SWAPOUT:
 		/*
 		 * Trigger PTE-mapping the THP by temporarily mapping a single
-		 * subpage R/O.
+		 * subpage R/O. This is a noop if the THP is not pmdsize (and
+		 * therefore already PTE-mapped).
 		 */
 		ret = mprotect(mem + pagesize, pagesize, PROT_READ);
 		if (ret) {
@@ -797,7 +801,7 @@  static void do_run_with_thp(test_fn fn, enum thp_run thp_run)
 		 * Discard all but a single subpage of that PTE-mapped THP. What
 		 * remains is a single PTE mapping a single subpage.
 		 */
-		ret = madvise(mem + pagesize, thpsize - pagesize, MADV_DONTNEED);
+		ret = madvise(mem + pagesize, size - pagesize, MADV_DONTNEED);
 		if (ret) {
 			ksft_test_result_fail("MADV_DONTNEED failed\n");
 			goto munmap;
@@ -809,7 +813,7 @@  static void do_run_with_thp(test_fn fn, enum thp_run thp_run)
 		 * Remap half of the THP. We need some new memory location
 		 * for that.
 		 */
-		mremap_size = thpsize / 2;
+		mremap_size = size / 2;
 		mremap_mem = mmap(NULL, mremap_size, PROT_NONE,
 				  MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 		if (mem == MAP_FAILED) {
@@ -830,7 +834,7 @@  static void do_run_with_thp(test_fn fn, enum thp_run thp_run)
 		 * child. This will result in some parts of the THP never
 		 * have been shared.
 		 */
-		ret = madvise(mem + pagesize, thpsize - pagesize, MADV_DONTFORK);
+		ret = madvise(mem + pagesize, size - pagesize, MADV_DONTFORK);
 		if (ret) {
 			ksft_test_result_fail("MADV_DONTFORK failed\n");
 			goto munmap;
@@ -844,7 +848,7 @@  static void do_run_with_thp(test_fn fn, enum thp_run thp_run)
 		}
 		wait(&ret);
 		/* Allow for sharing all pages again. */
-		ret = madvise(mem + pagesize, thpsize - pagesize, MADV_DOFORK);
+		ret = madvise(mem + pagesize, size - pagesize, MADV_DOFORK);
 		if (ret) {
 			ksft_test_result_fail("MADV_DOFORK failed\n");
 			goto munmap;
@@ -875,52 +879,60 @@  static void do_run_with_thp(test_fn fn, enum thp_run thp_run)
 		munmap(mremap_mem, mremap_size);
 }

-static void run_with_thp(test_fn fn, const char *desc)
+static void run_with_thp(test_fn fn, const char *desc, size_t size)
 {
-	ksft_print_msg("[RUN] %s ... with THP\n", desc);
-	do_run_with_thp(fn, THP_RUN_PMD);
+	ksft_print_msg("[RUN] %s ... with THP (%zu kB)\n",
+		desc, size / 1024);
+	do_run_with_thp(fn, THP_RUN_PMD, size);
 }

-static void run_with_thp_swap(test_fn fn, const char *desc)
+static void run_with_thp_swap(test_fn fn, const char *desc, size_t size)
 {
-	ksft_print_msg("[RUN] %s ... with swapped-out THP\n", desc);
-	do_run_with_thp(fn, THP_RUN_PMD_SWAPOUT);
+	ksft_print_msg("[RUN] %s ... with swapped-out THP (%zu kB)\n",
+		desc, size / 1024);
+	do_run_with_thp(fn, THP_RUN_PMD_SWAPOUT, size);
 }

-static void run_with_pte_mapped_thp(test_fn fn, const char *desc)
+static void run_with_pte_mapped_thp(test_fn fn, const char *desc, size_t size)
 {
-	ksft_print_msg("[RUN] %s ... with PTE-mapped THP\n", desc);
-	do_run_with_thp(fn, THP_RUN_PTE);
+	ksft_print_msg("[RUN] %s ... with PTE-mapped THP (%zu kB)\n",
+		desc, size / 1024);
+	do_run_with_thp(fn, THP_RUN_PTE, size);
 }

-static void run_with_pte_mapped_thp_swap(test_fn fn, const char *desc)
+static void run_with_pte_mapped_thp_swap(test_fn fn, const char *desc, size_t size)
 {
-	ksft_print_msg("[RUN] %s ... with swapped-out, PTE-mapped THP\n", desc);
-	do_run_with_thp(fn, THP_RUN_PTE_SWAPOUT);
+	ksft_print_msg("[RUN] %s ... with swapped-out, PTE-mapped THP (%zu kB)\n",
+		desc, size / 1024);
+	do_run_with_thp(fn, THP_RUN_PTE_SWAPOUT, size);
 }

-static void run_with_single_pte_of_thp(test_fn fn, const char *desc)
+static void run_with_single_pte_of_thp(test_fn fn, const char *desc, size_t size)
 {
-	ksft_print_msg("[RUN] %s ... with single PTE of THP\n", desc);
-	do_run_with_thp(fn, THP_RUN_SINGLE_PTE);
+	ksft_print_msg("[RUN] %s ... with single PTE of THP (%zu kB)\n",
+		desc, size / 1024);
+	do_run_with_thp(fn, THP_RUN_SINGLE_PTE, size);
 }

-static void run_with_single_pte_of_thp_swap(test_fn fn, const char *desc)
+static void run_with_single_pte_of_thp_swap(test_fn fn, const char *desc, size_t size)
 {
-	ksft_print_msg("[RUN] %s ... with single PTE of swapped-out THP\n", desc);
-	do_run_with_thp(fn, THP_RUN_SINGLE_PTE_SWAPOUT);
+	ksft_print_msg("[RUN] %s ... with single PTE of swapped-out THP (%zu kB)\n",
+		desc, size / 1024);
+	do_run_with_thp(fn, THP_RUN_SINGLE_PTE_SWAPOUT, size);
 }

-static void run_with_partial_mremap_thp(test_fn fn, const char *desc)
+static void run_with_partial_mremap_thp(test_fn fn, const char *desc, size_t size)
 {
-	ksft_print_msg("[RUN] %s ... with partially mremap()'ed THP\n", desc);
-	do_run_with_thp(fn, THP_RUN_PARTIAL_MREMAP);
+	ksft_print_msg("[RUN] %s ... with partially mremap()'ed THP (%zu kB)\n",
+		desc, size / 1024);
+	do_run_with_thp(fn, THP_RUN_PARTIAL_MREMAP, size);
 }

-static void run_with_partial_shared_thp(test_fn fn, const char *desc)
+static void run_with_partial_shared_thp(test_fn fn, const char *desc, size_t size)
 {
-	ksft_print_msg("[RUN] %s ... with partially shared THP\n", desc);
-	do_run_with_thp(fn, THP_RUN_PARTIAL_SHARED);
+	ksft_print_msg("[RUN] %s ... with partially shared THP (%zu kB)\n",
+		desc, size / 1024);
+	do_run_with_thp(fn, THP_RUN_PARTIAL_SHARED, size);
 }

 static void run_with_hugetlb(test_fn fn, const char *desc, size_t hugetlbsize)
@@ -1091,15 +1103,15 @@  static void run_anon_test_case(struct test_case const *test_case)

 	run_with_base_page(test_case->fn, test_case->desc);
 	run_with_base_page_swap(test_case->fn, test_case->desc);
-	if (thpsize) {
-		run_with_thp(test_case->fn, test_case->desc);
-		run_with_thp_swap(test_case->fn, test_case->desc);
-		run_with_pte_mapped_thp(test_case->fn, test_case->desc);
-		run_with_pte_mapped_thp_swap(test_case->fn, test_case->desc);
-		run_with_single_pte_of_thp(test_case->fn, test_case->desc);
-		run_with_single_pte_of_thp_swap(test_case->fn, test_case->desc);
-		run_with_partial_mremap_thp(test_case->fn, test_case->desc);
-		run_with_partial_shared_thp(test_case->fn, test_case->desc);
+	if (pmdsize) {
+		run_with_thp(test_case->fn, test_case->desc, pmdsize);
+		run_with_thp_swap(test_case->fn, test_case->desc, pmdsize);
+		run_with_pte_mapped_thp(test_case->fn, test_case->desc, pmdsize);
+		run_with_pte_mapped_thp_swap(test_case->fn, test_case->desc, pmdsize);
+		run_with_single_pte_of_thp(test_case->fn, test_case->desc, pmdsize);
+		run_with_single_pte_of_thp_swap(test_case->fn, test_case->desc, pmdsize);
+		run_with_partial_mremap_thp(test_case->fn, test_case->desc, pmdsize);
+		run_with_partial_shared_thp(test_case->fn, test_case->desc, pmdsize);
 	}
 	for (i = 0; i < nr_hugetlbsizes; i++)
 		run_with_hugetlb(test_case->fn, test_case->desc,
@@ -1120,7 +1132,7 @@  static int tests_per_anon_test_case(void)
 {
 	int tests = 2 + nr_hugetlbsizes;

-	if (thpsize)
+	if (pmdsize)
 		tests += 8;
 	return tests;
 }
@@ -1329,7 +1341,7 @@  static void run_anon_thp_test_cases(void)
 {
 	int i;

-	if (!thpsize)
+	if (!pmdsize)
 		return;

 	ksft_print_msg("[INFO] Anonymous THP tests\n");
@@ -1338,13 +1350,13 @@  static void run_anon_thp_test_cases(void)
 		struct test_case const *test_case = &anon_thp_test_cases[i];

 		ksft_print_msg("[RUN] %s\n", test_case->desc);
-		do_run_with_thp(test_case->fn, THP_RUN_PMD);
+		do_run_with_thp(test_case->fn, THP_RUN_PMD, pmdsize);
 	}
 }

 static int tests_per_anon_thp_test_case(void)
 {
-	return thpsize ? 1 : 0;
+	return pmdsize ? 1 : 0;
 }

 typedef void (*non_anon_test_fn)(char *mem, const char *smem, size_t size);
@@ -1419,7 +1431,7 @@  static void run_with_huge_zeropage(non_anon_test_fn fn, const char *desc)
 	}

 	/* For alignment purposes, we need twice the thp size. */
-	mmap_size = 2 * thpsize;
+	mmap_size = 2 * pmdsize;
 	mmap_mem = mmap(NULL, mmap_size, PROT_READ | PROT_WRITE,
 			MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 	if (mmap_mem == MAP_FAILED) {
@@ -1434,11 +1446,11 @@  static void run_with_huge_zeropage(non_anon_test_fn fn, const char *desc)
 	}

 	/* We need a THP-aligned memory area. */
-	mem = (char *)(((uintptr_t)mmap_mem + thpsize) & ~(thpsize - 1));
-	smem = (char *)(((uintptr_t)mmap_smem + thpsize) & ~(thpsize - 1));
+	mem = (char *)(((uintptr_t)mmap_mem + pmdsize) & ~(pmdsize - 1));
+	smem = (char *)(((uintptr_t)mmap_smem + pmdsize) & ~(pmdsize - 1));

-	ret = madvise(mem, thpsize, MADV_HUGEPAGE);
-	ret |= madvise(smem, thpsize, MADV_HUGEPAGE);
+	ret = madvise(mem, pmdsize, MADV_HUGEPAGE);
+	ret |= madvise(smem, pmdsize, MADV_HUGEPAGE);
 	if (ret) {
 		ksft_test_result_fail("MADV_HUGEPAGE failed\n");
 		goto munmap;
@@ -1457,7 +1469,7 @@  static void run_with_huge_zeropage(non_anon_test_fn fn, const char *desc)
 		goto munmap;
 	}

-	fn(mem, smem, thpsize);
+	fn(mem, smem, pmdsize);
 munmap:
 	munmap(mmap_mem, mmap_size);
 	if (mmap_smem != MAP_FAILED)
@@ -1650,7 +1662,7 @@  static void run_non_anon_test_case(struct non_anon_test_case const *test_case)
 	run_with_zeropage(test_case->fn, test_case->desc);
 	run_with_memfd(test_case->fn, test_case->desc);
 	run_with_tmpfile(test_case->fn, test_case->desc);
-	if (thpsize)
+	if (pmdsize)
 		run_with_huge_zeropage(test_case->fn, test_case->desc);
 	for (i = 0; i < nr_hugetlbsizes; i++)
 		run_with_memfd_hugetlb(test_case->fn, test_case->desc,
@@ -1671,7 +1683,7 @@  static int tests_per_non_anon_test_case(void)
 {
 	int tests = 3 + nr_hugetlbsizes;

-	if (thpsize)
+	if (pmdsize)
 		tests += 1;
 	return tests;
 }
@@ -1681,10 +1693,10 @@  int main(int argc, char **argv)
 	int err;

 	pagesize = getpagesize();
-	thpsize = read_pmd_pagesize();
-	if (thpsize)
-		ksft_print_msg("[INFO] detected THP size: %zu KiB\n",
-			       thpsize / 1024);
+	pmdsize = read_pmd_pagesize();
+	if (pmdsize)
+		ksft_print_msg("[INFO] detected PMD-mapped THP size: %zu KiB\n",
+			       pmdsize / 1024);
 	nr_hugetlbsizes = detect_hugetlb_page_sizes(hugetlbsizes,
 						    ARRAY_SIZE(hugetlbsizes));
 	detect_huge_zeropage();