Libhugetlbfs is not being maintained actively, and some distro is
dropping support for it. There are some tests that are good for testing
hugetlb functionality in kernel, which can be migrated to either kernel
kselftests or LTP.
I am submitting this patch to get comments from community on the
following
1. The test framework in ltp is most suitable for the tests that are
in libhugetlbfs/tests/ which follow similar test framework. And there
is already a section for hugetlb specific tests in LTP. So it makes
more sense and less effort to migrate the test to LTP. Though I
recommend migrating these tests to LTP, I would like to discuss tests
should be migrated to LTP or kselftests.
2. Libhugetlbfs tests has license GNU Lesser GPL 2.1 or later, while
kernel and LTP has license GPL2 or later, so can the test be
migrated to kernel/kselftests or LTP.
The below patch is libhugetlbfs/tests/direct.c which has been migrated
to ltp/testcases/kernel/mem/hugetlb/hugemmap/hugemmap07.c
Signed-off-by: Tarun Sahu <[email protected]>
---
runtest/hugetlb | 2 +
testcases/kernel/mem/.gitignore | 1 +
.../kernel/mem/hugetlb/hugemmap/hugemmap07.c | 106 ++++++++++++++++++
3 files changed, 109 insertions(+)
create mode 100644 testcases/kernel/mem/hugetlb/hugemmap/hugemmap07.c
diff --git a/runtest/hugetlb b/runtest/hugetlb
index f719217ab..ee02835d3 100644
--- a/runtest/hugetlb
+++ b/runtest/hugetlb
@@ -3,6 +3,8 @@ hugemmap02 hugemmap02
hugemmap04 hugemmap04
hugemmap05 hugemmap05
hugemmap06 hugemmap06
+hugemmap07 hugemmap07
+
hugemmap05_1 hugemmap05 -m
hugemmap05_2 hugemmap05 -s
hugemmap05_3 hugemmap05 -s -m
diff --git a/testcases/kernel/mem/.gitignore b/testcases/kernel/mem/.gitignore
index ff2910533..df5256ec8 100644
--- a/testcases/kernel/mem/.gitignore
+++ b/testcases/kernel/mem/.gitignore
@@ -4,6 +4,7 @@
/hugetlb/hugemmap/hugemmap04
/hugetlb/hugemmap/hugemmap05
/hugetlb/hugemmap/hugemmap06
+/hugetlb/hugemmap/hugemmap07
/hugetlb/hugeshmat/hugeshmat01
/hugetlb/hugeshmat/hugeshmat02
/hugetlb/hugeshmat/hugeshmat03
diff --git a/testcases/kernel/mem/hugetlb/hugemmap/hugemmap07.c b/testcases/kernel/mem/hugetlb/hugemmap/hugemmap07.c
new file mode 100644
index 000000000..798735ed0
--- /dev/null
+++ b/testcases/kernel/mem/hugetlb/hugemmap/hugemmap07.c
@@ -0,0 +1,106 @@
+/*
+ * License/Copyright Details
+ */
+
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <sys/mount.h>
+#include <limits.h>
+#include <sys/param.h>
+#include <sys/types.h>
+
+#include "tst_test.h"
+
+#define P0 "ffffffff"
+#define IOSZ 4096
+char buf[IOSZ] __attribute__((aligned(IOSZ)));
+static int fildes = -1, nfildes = -1;
+static char TEMPFILE[MAXPATHLEN];
+static char NTEMPFILE[MAXPATHLEN];
+
+void test_directio(void)
+{
+ long hpage_size;
+ void *p;
+ int ret;
+
+ hpage_size = SAFE_READ_MEMINFO("Hugepagesize:");
+
+ fildes = SAFE_OPEN(TEMPFILE, O_RDWR | O_CREAT, 0600);
+ nfildes = SAFE_OPEN(NTEMPFILE, O_CREAT|O_EXCL|O_RDWR|O_DIRECT, 0600);
+
+ p = mmap(NULL, hpage_size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fildes, 0);
+ if (p == MAP_FAILED)
+ tst_brk(TFAIL | TERRNO, "mmap() Failed on %s", TEMPFILE);
+
+ memcpy(p, P0, 8);
+
+ /* Direct write from huge page */
+ ret = write(nfildes, p, IOSZ);
+ if (ret == -1)
+ tst_brk(TFAIL | TERRNO, "Direct-IO write from huge page");
+ if (ret != IOSZ)
+ tst_brk(TFAIL, "Short direct-IO write from huge page");
+ if (lseek(nfildes, 0, SEEK_SET) == -1)
+ tst_brk(TFAIL | TERRNO, "lseek");
+
+ /* Check for accuracy */
+ ret = read(nfildes, buf, IOSZ);
+ if (ret == -1)
+ tst_brk(TFAIL | TERRNO, "Direct-IO read to normal memory");
+ if (ret != IOSZ)
+ tst_brk(TFAIL, "Short direct-IO read to normal memory");
+ if (memcmp(P0, buf, 8))
+ tst_brk(TFAIL, "Memory mismatch after Direct-IO write");
+ if (lseek(nfildes, 0, SEEK_SET) == -1)
+ tst_brk(TFAIL | TERRNO, "lseek");
+
+ /* Direct read to huge page */
+ memset(p, 0, IOSZ);
+ ret = read(nfildes, p, IOSZ);
+ if (ret == -1)
+ tst_brk(TFAIL | TERRNO, "Direct-IO read to huge page");
+ if (ret != IOSZ)
+ tst_brk(TFAIL, "Short direct-IO read to huge page");
+
+ /* Check for accuracy */
+ if (memcmp(p, P0, 8))
+ tst_brk(TFAIL, "Memory mismatch after Direct-IO read");
+ tst_res(TPASS, "Successfully tested Hugepage Direct I/O");
+}
+
+void setup(void)
+{
+ if (tst_hugepages == 0)
+ tst_brk(TCONF, "Not enough hugepages for testing.");
+
+ if (!Hopt)
+ Hopt = tst_get_tmpdir();
+ SAFE_MOUNT("none", Hopt, "hugetlbfs", 0, NULL);
+
+ snprintf(TEMPFILE, sizeof(TEMPFILE), "%s/mmapfile%d", Hopt, getpid());
+ snprintf(NTEMPFILE, sizeof(NTEMPFILE), "%s/nmmapfile%d", "/home/", getpid());
+}
+
+void cleanup(void)
+{
+ close(fildes);
+ close(nfildes);
+ remove(TEMPFILE);
+ remove(NTEMPFILE);
+ umount2(Hopt, MNT_DETACH);
+}
+
+static struct tst_test test = {
+ .needs_root = 1,
+ .needs_tmpdir = 1,
+ .options = (struct tst_option[]) {
+ {"H:", &Hopt, "Location of hugetlbfs, i.e. -H /var/hugetlbfs"},
+ {"s:", &nr_opt, "Set the number of the been allocated hugepages"},
+ {}
+ },
+ .setup = setup,
+ .cleanup = cleanup,
+ .test_all = test_directio,
+ .hugepages = {2, TST_REQUEST},
+};
--
2.31.1
Hi!
> Signed-off-by: Tarun Sahu <[email protected]>
> ---
> runtest/hugetlb | 2 +
> testcases/kernel/mem/.gitignore | 1 +
> .../kernel/mem/hugetlb/hugemmap/hugemmap07.c | 106 ++++++++++++++++++
> 3 files changed, 109 insertions(+)
> create mode 100644 testcases/kernel/mem/hugetlb/hugemmap/hugemmap07.c
>
> diff --git a/runtest/hugetlb b/runtest/hugetlb
> index f719217ab..ee02835d3 100644
> --- a/runtest/hugetlb
> +++ b/runtest/hugetlb
> @@ -3,6 +3,8 @@ hugemmap02 hugemmap02
> hugemmap04 hugemmap04
> hugemmap05 hugemmap05
> hugemmap06 hugemmap06
> +hugemmap07 hugemmap07
> +
> hugemmap05_1 hugemmap05 -m
> hugemmap05_2 hugemmap05 -s
> hugemmap05_3 hugemmap05 -s -m
> diff --git a/testcases/kernel/mem/.gitignore b/testcases/kernel/mem/.gitignore
> index ff2910533..df5256ec8 100644
> --- a/testcases/kernel/mem/.gitignore
> +++ b/testcases/kernel/mem/.gitignore
> @@ -4,6 +4,7 @@
> /hugetlb/hugemmap/hugemmap04
> /hugetlb/hugemmap/hugemmap05
> /hugetlb/hugemmap/hugemmap06
> +/hugetlb/hugemmap/hugemmap07
> /hugetlb/hugeshmat/hugeshmat01
> /hugetlb/hugeshmat/hugeshmat02
> /hugetlb/hugeshmat/hugeshmat03
> diff --git a/testcases/kernel/mem/hugetlb/hugemmap/hugemmap07.c b/testcases/kernel/mem/hugetlb/hugemmap/hugemmap07.c
> new file mode 100644
> index 000000000..798735ed0
> --- /dev/null
> +++ b/testcases/kernel/mem/hugetlb/hugemmap/hugemmap07.c
> @@ -0,0 +1,106 @@
> +/*
> + * License/Copyright Details
> + */
There should be a SPDX licence identifier here instead.
Also testcase should include a special ascii-doc formatted comment here
that describes the purpose of the test.
> +#define _GNU_SOURCE
> +#include <stdio.h>
> +#include <sys/mount.h>
> +#include <limits.h>
> +#include <sys/param.h>
> +#include <sys/types.h>
> +
> +#include "tst_test.h"
> +
> +#define P0 "ffffffff"
> +#define IOSZ 4096
> +char buf[IOSZ] __attribute__((aligned(IOSZ)));
> +static int fildes = -1, nfildes = -1;
> +static char TEMPFILE[MAXPATHLEN];
> +static char NTEMPFILE[MAXPATHLEN];
Uppercase is reserved for macros in C.
Have you run 'make check' to check for common mistakes before
submitting?
> +void test_directio(void)
should be static
> +{
> + long hpage_size;
> + void *p;
> + int ret;
> +
> + hpage_size = SAFE_READ_MEMINFO("Hugepagesize:");
> +
> + fildes = SAFE_OPEN(TEMPFILE, O_RDWR | O_CREAT, 0600);
> + nfildes = SAFE_OPEN(NTEMPFILE, O_CREAT|O_EXCL|O_RDWR|O_DIRECT, 0600);
I would say that fd and nfd in the original code was were better names,
shorter and to the point. See also:
https://github.com/linux-test-project/ltp/wiki/Test-Writing-Guidelines
> + p = mmap(NULL, hpage_size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fildes, 0);
> + if (p == MAP_FAILED)
> + tst_brk(TFAIL | TERRNO, "mmap() Failed on %s", TEMPFILE);
We do have SAFE_MMAP() as well.
> + memcpy(p, P0, 8);
> +
> + /* Direct write from huge page */
> + ret = write(nfildes, p, IOSZ);
> + if (ret == -1)
> + tst_brk(TFAIL | TERRNO, "Direct-IO write from huge page");
> + if (ret != IOSZ)
> + tst_brk(TFAIL, "Short direct-IO write from huge page");
> + if (lseek(nfildes, 0, SEEK_SET) == -1)
> + tst_brk(TFAIL | TERRNO, "lseek");
> +
> + /* Check for accuracy */
> + ret = read(nfildes, buf, IOSZ);
> + if (ret == -1)
> + tst_brk(TFAIL | TERRNO, "Direct-IO read to normal memory");
> + if (ret != IOSZ)
> + tst_brk(TFAIL, "Short direct-IO read to normal memory");
> + if (memcmp(P0, buf, 8))
> + tst_brk(TFAIL, "Memory mismatch after Direct-IO write");
> + if (lseek(nfildes, 0, SEEK_SET) == -1)
> + tst_brk(TFAIL | TERRNO, "lseek");
And we have SAFE_WRITE(), SAFE_READ(), and SAFE_LSEEK() as well.
Also tst_brk(TFAIL, "") usage is deprecated and should not be used in
new tests.
> + /* Direct read to huge page */
> + memset(p, 0, IOSZ);
> + ret = read(nfildes, p, IOSZ);
> + if (ret == -1)
> + tst_brk(TFAIL | TERRNO, "Direct-IO read to huge page");
> + if (ret != IOSZ)
> + tst_brk(TFAIL, "Short direct-IO read to huge page");
> +
> + /* Check for accuracy */
> + if (memcmp(p, P0, 8))
> + tst_brk(TFAIL, "Memory mismatch after Direct-IO read");
> + tst_res(TPASS, "Successfully tested Hugepage Direct I/O");
You should close filedescriptors and unmap memory here, otherwise the
test will fail with large enough -i parameter.
> +}
> +
> +void setup(void)
should be static.
> +{
> + if (tst_hugepages == 0)
> + tst_brk(TCONF, "Not enough hugepages for testing.");
> +
> + if (!Hopt)
> + Hopt = tst_get_tmpdir();
> + SAFE_MOUNT("none", Hopt, "hugetlbfs", 0, NULL);
> +
> + snprintf(TEMPFILE, sizeof(TEMPFILE), "%s/mmapfile%d", Hopt, getpid());
Ideally all files created outside of the test temporary directory should
be prefixed with "ltp_"
> + snprintf(NTEMPFILE, sizeof(NTEMPFILE), "%s/nmmapfile%d", "/home/", getpid());
Please do not create any files outside of the test temporary directory,
also as the temporary directory is unique already, there is no need to
actually create the second tempfile name like this. All we need to do is
to is something as:
#define NTEMPFILE "tempfile"
> +}
> +
> +void cleanup(void)
> +{
> + close(fildes);
> + close(nfildes);
> + remove(TEMPFILE);
> + remove(NTEMPFILE);
> + umount2(Hopt, MNT_DETACH);
> +}
> +
> +static struct tst_test test = {
> + .needs_root = 1,
> + .needs_tmpdir = 1,
> + .options = (struct tst_option[]) {
> + {"H:", &Hopt, "Location of hugetlbfs, i.e. -H /var/hugetlbfs"},
> + {"s:", &nr_opt, "Set the number of the been allocated hugepages"},
> + {}
> + },
> + .setup = setup,
> + .cleanup = cleanup,
> + .test_all = test_directio,
> + .hugepages = {2, TST_REQUEST},
> +};
> --
> 2.31.1
>
>
> --
> Mailing list info: https://lists.linux.it/listinfo/ltp
--
Cyril Hrubis
[email protected]
Hi Cyril, Thanks for reviewing the patch.
Below I have added my
comments. Will update changes in V2.
On Fri, 2022-09-09 at 11:06 +0200,
Cyril Hrubis wrote:
> Hi!
> > Signed-off-by: Tarun Sahu <[email protected]>
> > ---
> > runtest/hugetlb | 2 +
> > testcases/kernel/mem/.gitignore | 1 +
> > .../kernel/mem/hugetlb/hugemmap/hugemmap07.c | 106
> > ++++++++++++++++++
> > 3 files changed, 109 insertions(+)
> > create mode 100644
> > testcases/kernel/mem/hugetlb/hugemmap/hugemmap07.c
> >
> > diff --git a/runtest/hugetlb b/runtest/hugetlb
> > index f719217ab..ee02835d3 100644
> > --- a/runtest/hugetlb
> > +++ b/runtest/hugetlb
> > @@ -3,6 +3,8 @@ hugemmap02 hugemmap02
> > hugemmap04 hugemmap04
> > hugemmap05 hugemmap05
> > hugemmap06 hugemmap06
> > +hugemmap07 hugemmap07
> > +
> > hugemmap05_1 hugemmap05 -m
> > hugemmap05_2 hugemmap05 -s
> > hugemmap05_3 hugemmap05 -s -m
> > diff --git a/testcases/kernel/mem/.gitignore
> > b/testcases/kernel/mem/.gitignore
> > index ff2910533..df5256ec8 100644
> > --- a/testcases/kernel/mem/.gitignore
> > +++ b/testcases/kernel/mem/.gitignore
> > @@ -4,6 +4,7 @@
> > /hugetlb/hugemmap/hugemmap04
> > /hugetlb/hugemmap/hugemmap05
> > /hugetlb/hugemmap/hugemmap06
> > +/hugetlb/hugemmap/hugemmap07
> > /hugetlb/hugeshmat/hugeshmat01
> > /hugetlb/hugeshmat/hugeshmat02
> > /hugetlb/hugeshmat/hugeshmat03
> > diff --git a/testcases/kernel/mem/hugetlb/hugemmap/hugemmap07.c
> > b/testcases/kernel/mem/hugetlb/hugemmap/hugemmap07.c
> > new file mode 100644
> > index 000000000..798735ed0
> > --- /dev/null
> > +++ b/testcases/kernel/mem/hugetlb/hugemmap/hugemmap07.c
> > @@ -0,0 +1,106 @@
> > +/*
> > + * License/Copyright Details
> > + */
>
> There should be a SPDX licence identifier here instead.
>
> Also testcase should include a special ascii-doc formatted comment
> here
> that describes the purpose of the test.
As mentioned in the patch description, there is a conflict in license,
That is why, I have avoided to put any of them in the header. Once
confirmed within the community, I can add the original license here.
(GPL2.1+) as
https://github.com/linux-test-project/ltp/wiki/Test-Writing-Guidelines
this says only to add code with GPL2.0+.
>
> > +#define _GNU_SOURCE
> > +#include <stdio.h>
> > +#include <sys/mount.h>
> > +#include <limits.h>
> > +#include <sys/param.h>
> > +#include <sys/types.h>
> > +
> > +#include "tst_test.h"
> > +
> > +#define P0 "ffffffff"
> > +#define IOSZ 4096
> > +char buf[IOSZ] __attribute__((aligned(IOSZ)));
> > +static int fildes = -1, nfildes = -1;
> > +static char TEMPFILE[MAXPATHLEN];
> > +static char NTEMPFILE[MAXPATHLEN];
>
> Uppercase is reserved for macros in C.
>
> Have you run 'make check' to check for common mistakes before
> submitting?
>
> > +void test_directio(void)
>
> should be static
Ok Will update in V2.
>
> > +{
> > + long hpage_size;
> > + void *p;
> > + int ret;
> > +
> > + hpage_size = SAFE_READ_MEMINFO("Hugepagesize:");
> > +
> > + fildes = SAFE_OPEN(TEMPFILE, O_RDWR | O_CREAT, 0600);
> > + nfildes = SAFE_OPEN(NTEMPFILE, O_CREAT|O_EXCL|O_RDWR|O_DIRECT,
> > 0600);
>
> I would say that fd and nfd in the original code was were better
> names,
> shorter and to the point. See also:
>
> https://github.com/linux-test-project/ltp/wiki/Test-Writing-Guidelines
I agree, I tried to follow what was in hugemmap01..06 test cases to
keep things similar all across the tests. I will update it in v2.
>
> > + p = mmap(NULL, hpage_size, PROT_READ|PROT_WRITE, MAP_PRIVATE,
> > fildes, 0);
> > + if (p == MAP_FAILED)
> > + tst_brk(TFAIL | TERRNO, "mmap() Failed on %s",
> > TEMPFILE);
>
> We do have SAFE_MMAP() as well.
Yeah, I will update them in v2.
>
> > + memcpy(p, P0, 8);
> > +
> > + /* Direct write from huge page */
> > + ret = write(nfildes, p, IOSZ);
> > + if (ret == -1)
> > + tst_brk(TFAIL | TERRNO, "Direct-IO write from huge
> > page");
> > + if (ret != IOSZ)
> > + tst_brk(TFAIL, "Short direct-IO write from huge page");
> > + if (lseek(nfildes, 0, SEEK_SET) == -1)
> > + tst_brk(TFAIL | TERRNO, "lseek");
> > +
> > + /* Check for accuracy */
> > + ret = read(nfildes, buf, IOSZ);
> > + if (ret == -1)
> > + tst_brk(TFAIL | TERRNO, "Direct-IO read to normal
> > memory");
> > + if (ret != IOSZ)
> > + tst_brk(TFAIL, "Short direct-IO read to normal
> > memory");
> > + if (memcmp(P0, buf, 8))
> > + tst_brk(TFAIL, "Memory mismatch after Direct-IO
> > write");
> > + if (lseek(nfildes, 0, SEEK_SET) == -1)
> > + tst_brk(TFAIL | TERRNO, "lseek");
>
> And we have SAFE_WRITE(), SAFE_READ(), and SAFE_LSEEK() as well.
ok Will update these too in v2.
>
> Also tst_brk(TFAIL, "") usage is deprecated and should not be used in
> new tests.
Ok, Will update it to tst_res.
>
> > + /* Direct read to huge page */
> > + memset(p, 0, IOSZ);
> > + ret = read(nfildes, p, IOSZ);
> > + if (ret == -1)
> > + tst_brk(TFAIL | TERRNO, "Direct-IO read to huge page");
> > + if (ret != IOSZ)
> > + tst_brk(TFAIL, "Short direct-IO read to huge page");
> > +
> > + /* Check for accuracy */
> > + if (memcmp(p, P0, 8))
> > + tst_brk(TFAIL, "Memory mismatch after Direct-IO read");
> > + tst_res(TPASS, "Successfully tested Hugepage Direct I/O");
>
> You should close filedescriptors and unmap memory here, otherwise the
> test will fail with large enough -i parameter.
Ok, I will update it too in v2.
>
> > +}
> > +
> > +void setup(void)
>
> should be static.
Ok Will update it in V2.
>
> > +{
> > + if (tst_hugepages == 0)
> > + tst_brk(TCONF, "Not enough hugepages for testing.");
> > +
> > + if (!Hopt)
> > + Hopt = tst_get_tmpdir();
> > + SAFE_MOUNT("none", Hopt, "hugetlbfs", 0, NULL);
> > +
> > + snprintf(TEMPFILE, sizeof(TEMPFILE), "%s/mmapfile%d", Hopt,
> > getpid());
>
> Ideally all files created outside of the test temporary directory
> should
> be prefixed with "ltp_"
ok, Will update it in V2.
>
> > + snprintf(NTEMPFILE, sizeof(NTEMPFILE), "%s/nmmapfile%d",
> > "/home/", getpid());
>
> Please do not create any files outside of the test temporary
> directory,
> also as the temporary directory is unique already, there is no need
> to
> actually create the second tempfile name like this. All we need to do
> is
> to is something as:
>
> #define NTEMPFILE "tempfile"
>
Ok Will update it in V2.
> > +}
> > +
> > +void cleanup(void)
> > +{
> > + close(fildes);
> > + close(nfildes);
> > + remove(TEMPFILE);
> > + remove(NTEMPFILE);
> > + umount2(Hopt, MNT_DETACH);
> > +}
> > +
> > +static struct tst_test test = {
> > + .needs_root = 1,
> > + .needs_tmpdir = 1,
> > + .options = (struct tst_option[]) {
> > + {"H:", &Hopt, "Location of hugetlbfs, i.e. -H
> > /var/hugetlbfs"},
> > + {"s:", &nr_opt, "Set the number of the been allocated
> > hugepages"},
> > + {}
> > + },
> > + .setup = setup,
> > + .cleanup = cleanup,
> > + .test_all = test_directio,
> > + .hugepages = {2, TST_REQUEST},
> > +};
> > --
> > 2.31.1
> >
> >
> > --
> > Mailing list info: https://lists.linux.it/listinfo/ltp
Hi!
> As mentioned in the patch description, there is a conflict in license,
> That is why, I have avoided to put any of them in the header. Once
> confirmed within the community, I can add the original license here.
> (GPL2.1+) as
> https://github.com/linux-test-project/ltp/wiki/Test-Writing-Guidelines
> this says only to add code with GPL2.0+.
As far as I can tell there is no GPL2.1+ the only 2.1 version in
existence is LGPL.
GPL2.1+ usually happens to be an error when someone takes library header
with LGPL2.1+ license and removes the "Lesser" part.
However it looks like the whole libhugetlbfs is under LGPL2.1+ which
kind of makes sense for a library, but not so much for the tests since
these do not provide a library that can be linked againts at all.
--
Cyril Hrubis
[email protected]
Hi,
Thanks for confirming.
There is one more confirmation I required
before I submit a patch series on necessary libhugetlbfs tests,
Between
LTP and Kselftests, Choosing LTP is right decision? (mentioned details
in patch description)
Thanks
On Mon, 2022-09-12 at 10:43 +0200, Cyril Hrubis wrote:
> Hi!
> > As mentioned in the patch description, there is a conflict in
> > license,
> > That is why, I have avoided to put any of them in the header. Once
> > confirmed within the community, I can add the original license
> > here.
> > (GPL2.1+) as
> > https://github.com/linux-test-project/ltp/wiki/Test-Writing-Guidelines
> > this says only to add code with GPL2.0+.
>
> As far as I can tell there is no GPL2.1+ the only 2.1 version in
> existence is LGPL.
>
> GPL2.1+ usually happens to be an error when someone takes library
> header
> with LGPL2.1+ license and removes the "Lesser" part.
>
> However it looks like the whole libhugetlbfs is under LGPL2.1+ which
> kind of makes sense for a library, but not so much for the tests
> since
> these do not provide a library that can be linked againts at all.
>