| Message ID | 20250318174343.243631-1-ryan.roberts@arm.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [v1,1/3] selftests/mm: Fix half_ufd_size_MB calculation | expand |
On Tue, Mar 18, 2025 at 05:43:39PM +0000, Ryan Roberts wrote: > $half_ufd_size_MB is supposed to be half of the available hugetlb memory > expressed in MB. But previously it was calculated in pages since > $freepgs is the number of free pages. > > When huge pages are 2M it doesn't make a whole lot of difference; the > number of pages that get used is just halved. But on arm64 with 16K or > 64K base pages, the PMD size (and default hugetlb size) is 32M and 512M > respectively. So in this case we end up passing a number of MB that is > smaller than a single hugetlb page and the test raises an error. > > Fixes: 2e47a445d7b3 ("selftests/mm: run_vmtests.sh: fix hugetlb mem size calculation") > Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> There's a similar fix already in akpm/mm-hotfixes-stable: 67a2f86846f2 selftests/mm: run_vmtests.sh: fix half_ufd_size_MB calculation Thanks, > --- > tools/testing/selftests/mm/run_vmtests.sh | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/tools/testing/selftests/mm/run_vmtests.sh b/tools/testing/selftests/mm/run_vmtests.sh > index da7e26668103..14fa9d40d574 100755 > --- a/tools/testing/selftests/mm/run_vmtests.sh > +++ b/tools/testing/selftests/mm/run_vmtests.sh > @@ -304,7 +304,7 @@ uffd_stress_bin=./uffd-stress > CATEGORY="userfaultfd" run_test ${uffd_stress_bin} anon 20 16 > # Hugetlb tests require source and destination huge pages. Pass in half > # the size of the free pages we have, which is used for *each*. > -half_ufd_size_MB=$((freepgs / 2)) > +half_ufd_size_MB=$(((freepgs * hpgsize_KB / 2) / 1024)) > CATEGORY="userfaultfd" run_test ${uffd_stress_bin} hugetlb "$half_ufd_size_MB" 32 > CATEGORY="userfaultfd" run_test ${uffd_stress_bin} hugetlb-private "$half_ufd_size_MB" 32 > CATEGORY="userfaultfd" run_test ${uffd_stress_bin} shmem 20 16 > -- > 2.43.0 >
On Tue, Mar 18, 2025 at 05:43:39PM +0000, Ryan Roberts wrote: > $half_ufd_size_MB is supposed to be half of the available hugetlb memory > expressed in MB. But previously it was calculated in pages since > $freepgs is the number of free pages. > > When huge pages are 2M it doesn't make a whole lot of difference; the > number of pages that get used is just halved. But on arm64 with 16K or > 64K base pages, the PMD size (and default hugetlb size) is 32M and 512M > respectively. So in this case we end up passing a number of MB that is > smaller than a single hugetlb page and the test raises an error. > > Fixes: 2e47a445d7b3 ("selftests/mm: run_vmtests.sh: fix hugetlb mem size calculation") > Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> > --- > tools/testing/selftests/mm/run_vmtests.sh | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/tools/testing/selftests/mm/run_vmtests.sh b/tools/testing/selftests/mm/run_vmtests.sh > index da7e26668103..14fa9d40d574 100755 > --- a/tools/testing/selftests/mm/run_vmtests.sh > +++ b/tools/testing/selftests/mm/run_vmtests.sh > @@ -304,7 +304,7 @@ uffd_stress_bin=./uffd-stress > CATEGORY="userfaultfd" run_test ${uffd_stress_bin} anon 20 16 > # Hugetlb tests require source and destination huge pages. Pass in half > # the size of the free pages we have, which is used for *each*. > -half_ufd_size_MB=$((freepgs / 2)) > +half_ufd_size_MB=$(((freepgs * hpgsize_KB / 2) / 1024)) > CATEGORY="userfaultfd" run_test ${uffd_stress_bin} hugetlb "$half_ufd_size_MB" 32 > CATEGORY="userfaultfd" run_test ${uffd_stress_bin} hugetlb-private "$half_ufd_size_MB" 32 > CATEGORY="userfaultfd" run_test ${uffd_stress_bin} shmem 20 16 > -- > 2.43.0 > > this one is already fixed in linux-next, see commit 67a2f86846f2 ("selftests/mm: run_vmtests.sh: fix half_ufd_size_MB calculation") -- Rafael
On 18/03/2025 19:54, Peter Xu wrote: > On Tue, Mar 18, 2025 at 05:43:39PM +0000, Ryan Roberts wrote: >> $half_ufd_size_MB is supposed to be half of the available hugetlb memory >> expressed in MB. But previously it was calculated in pages since >> $freepgs is the number of free pages. >> >> When huge pages are 2M it doesn't make a whole lot of difference; the >> number of pages that get used is just halved. But on arm64 with 16K or >> 64K base pages, the PMD size (and default hugetlb size) is 32M and 512M >> respectively. So in this case we end up passing a number of MB that is >> smaller than a single hugetlb page and the test raises an error. >> >> Fixes: 2e47a445d7b3 ("selftests/mm: run_vmtests.sh: fix hugetlb mem size calculation") >> Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> > > There's a similar fix already in akpm/mm-hotfixes-stable: > > 67a2f86846f2 selftests/mm: run_vmtests.sh: fix half_ufd_size_MB calculation Oops, my bad, forgot to check mm branches. This was just a drive-by fix while working in another context. Hopefully Andrew is ok to take the other 2 patches and drop this one? If not, let me know and I'll resend the two other patches on their own. Thanks, Ryan > > Thanks, > >> --- >> tools/testing/selftests/mm/run_vmtests.sh | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/tools/testing/selftests/mm/run_vmtests.sh b/tools/testing/selftests/mm/run_vmtests.sh >> index da7e26668103..14fa9d40d574 100755 >> --- a/tools/testing/selftests/mm/run_vmtests.sh >> +++ b/tools/testing/selftests/mm/run_vmtests.sh >> @@ -304,7 +304,7 @@ uffd_stress_bin=./uffd-stress >> CATEGORY="userfaultfd" run_test ${uffd_stress_bin} anon 20 16 >> # Hugetlb tests require source and destination huge pages. Pass in half >> # the size of the free pages we have, which is used for *each*. >> -half_ufd_size_MB=$((freepgs / 2)) >> +half_ufd_size_MB=$(((freepgs * hpgsize_KB / 2) / 1024)) >> CATEGORY="userfaultfd" run_test ${uffd_stress_bin} hugetlb "$half_ufd_size_MB" 32 >> CATEGORY="userfaultfd" run_test ${uffd_stress_bin} hugetlb-private "$half_ufd_size_MB" 32 >> CATEGORY="userfaultfd" run_test ${uffd_stress_bin} shmem 20 16 >> -- >> 2.43.0 >> >
diff --git a/tools/testing/selftests/mm/run_vmtests.sh b/tools/testing/selftests/mm/run_vmtests.sh index da7e26668103..14fa9d40d574 100755 --- a/tools/testing/selftests/mm/run_vmtests.sh +++ b/tools/testing/selftests/mm/run_vmtests.sh @@ -304,7 +304,7 @@ uffd_stress_bin=./uffd-stress CATEGORY="userfaultfd" run_test ${uffd_stress_bin} anon 20 16 # Hugetlb tests require source and destination huge pages. Pass in half # the size of the free pages we have, which is used for *each*. -half_ufd_size_MB=$((freepgs / 2)) +half_ufd_size_MB=$(((freepgs * hpgsize_KB / 2) / 1024)) CATEGORY="userfaultfd" run_test ${uffd_stress_bin} hugetlb "$half_ufd_size_MB" 32 CATEGORY="userfaultfd" run_test ${uffd_stress_bin} hugetlb-private "$half_ufd_size_MB" 32 CATEGORY="userfaultfd" run_test ${uffd_stress_bin} shmem 20 16
$half_ufd_size_MB is supposed to be half of the available hugetlb memory expressed in MB. But previously it was calculated in pages since $freepgs is the number of free pages. When huge pages are 2M it doesn't make a whole lot of difference; the number of pages that get used is just halved. But on arm64 with 16K or 64K base pages, the PMD size (and default hugetlb size) is 32M and 512M respectively. So in this case we end up passing a number of MB that is smaller than a single hugetlb page and the test raises an error. Fixes: 2e47a445d7b3 ("selftests/mm: run_vmtests.sh: fix hugetlb mem size calculation") Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> --- tools/testing/selftests/mm/run_vmtests.sh | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) -- 2.43.0