On (09/10/08 20:20), Andy Whitcroft didst pronounce:
> From: Adam Litke <[EMAIL PROTECTED]>
>
> This patch fixes two intertwined issues:
>
> When the SHM_HUGETLB flag is passed to shmget(), the system default huge page
> size is used to back the shared memory segment. Unlike with mmap() there is
> not yet a way to use an alternate huge page size for shared memory segments.
> This exception must be taken into account by the shmget override function --
> it
> cannot call gethugepagesize() but must discover the effective huge page size
> by
> direct examination of /proc/meminfo. Make the shmoverride test case discover
> the huge page size in the same manner.
>
> The shmoverride_* test case does not always link against libhugetlbfs.
> Therefore, it cannot use the new mechanism for manipulating pool counters.
> Unfortunately, this means that the logic to read /proc/meminfo must be
> duplicated in order for shmoverride_unlinked to build as a NOLIB test.
>
> [EMAIL PROTECTED]: consolidate makefile updates in one place]
> Signed-off-by: Adam Litke <[EMAIL PROTECTED]>
> ---
> shm.c | 7 +++-
> tests/shmoverride_unlinked.c | 74
> ++++++++++++++++++++++++++++++++++++++----
> 2 files changed, 73 insertions(+), 8 deletions(-)
>
> diff --git a/shm.c b/shm.c
> index cc9995d..8a56725 100644
> --- a/shm.c
> +++ b/shm.c
> @@ -56,7 +56,12 @@ int shmget(key_t key, size_t size, int shmflg)
>
> /* Align the size and set SHM_HUGETLB on request */
> if (hugetlbshm_enabled) {
> - aligned_size = ALIGN(size, gethugepagesize());
> + /*
> + * Use /proc/meminfo because shm always uses the system
> + * default huge page size.
> + */
> + long hpage_size = read_meminfo("Hugepagesize:") * 1024;
> + aligned_size = ALIGN(size, hpage_size);
> if (size != aligned_size) {
> DEBUG("hugetlb_shmem: size growth align %zd -> %zd\n",
> size, aligned_size);
Ok.
> diff --git a/tests/shmoverride_unlinked.c b/tests/shmoverride_unlinked.c
> index a8af228..5813cb7 100644
> --- a/tests/shmoverride_unlinked.c
> +++ b/tests/shmoverride_unlinked.c
> @@ -26,6 +26,7 @@
> #include <unistd.h>
> #include <sys/stat.h>
> #include <fcntl.h>
> +#include <ctype.h>
> #include <hugetlbfs.h>
> #include "hugetests.h"
>
> @@ -94,11 +95,55 @@ void _shmunmap(int s, int line)
> }
> #define shmunmap(s) _shmunmap(s, __LINE__)
>
> +/*
> + * This test wants to manipulate the hugetlb pool without necessarily linking
> + * to libhugetlbfs so the helpers for doing this may not be available --
> hence
> + * the duplicated versions below.
> + *
> + * NOTE: We use /proc/sys/vm/nr_hugepages and /proc/meminfo for writing and
> + * reading pool counters because shared memory will always use the system
> + * default huge page size regardless of any libhugetlbfs settings.
> + */
> +#define MEMINFO_SIZE 2048
> +long local_read_meminfo(const char *tag)
> +{
> + int fd;
> + char buf[MEMINFO_SIZE];
> + int len, readerr;
> + char *p, *q;
> + long val;
> +
> + fd = open("/proc/meminfo", O_RDONLY);
> + if (fd < 0)
> + FAIL("Couldn't open /proc/meminfo: %s\n", strerror(errno));
> +
> + len = read(fd, buf, sizeof(buf));
> + readerr = errno;
> + close(fd);
> + if (len < 0)
> + FAIL("Error reading /proc/meminfo: %s\n", strerror(errno));
> +
> + if (len == sizeof(buf))
> + FAIL("/proc/meminfo is too large\n");
> + buf[len] = '\0';
> +
> + p = strstr(buf, tag);
> + if (!p)
> + FAIL("Tag %s not found in /proc/meminfo\n", tag);
> + p += strlen(tag);
> +
> + val = strtol(p, &q, 0);
> + if (!isspace(*q))
> + FAIL("Couldn't parse /proc/meminfo\n");
> +
> + return val;
> +}
> +
> void setup_hugetlb_pool(unsigned long count)
> {
> FILE *fd;
> unsigned long poolsize;
> - count += read_meminfo("HugePages_Rsvd:");
> + count += local_read_meminfo("HugePages_Rsvd:");
> fd = fopen("/proc/sys/vm/nr_hugepages", "w");
> if (!fd)
> CONFIG("Cannot open nr_hugepages for writing\n");
> @@ -106,12 +151,19 @@ void setup_hugetlb_pool(unsigned long count)
> fclose(fd);
>
> /* Confirm the resize worked */
> - poolsize = read_meminfo("HugePages_Total:");
> + poolsize = local_read_meminfo("HugePages_Total:");
> if (poolsize != count)
> FAIL("Failed to resize pool to %lu pages. Got %lu instead\n",
> count, poolsize);
> }
>
> +void local_check_free_huge_pages(int needed_pages)
> +{
> + int free = local_read_meminfo("HugePages_Free:");
> + if (free < needed_pages)
> + CONFIG("Must have at least %i free hugepages", needed_pages);
> +}
> +
> void run_test(char *desc, int hpages, int bpages, int pool_nr, int
> expect_diff)
> {
> long resv_before, resv_after;
> @@ -119,9 +171,9 @@ void run_test(char *desc, int hpages, int bpages, int
> pool_nr, int expect_diff)
> setup_hugetlb_pool(pool_nr);
>
> /* untouched, shared mmap */
> - resv_before = read_meminfo("HugePages_Rsvd:");
> + resv_before = local_read_meminfo("HugePages_Rsvd:");
> shmmap(SL_TEST, hpages, bpages);
> - resv_after = read_meminfo("HugePages_Rsvd:");
> + resv_after = local_read_meminfo("HugePages_Rsvd:");
> memset(map_addr[SL_TEST], 0, map_size[SL_TEST]);
> shmunmap(SL_TEST);
>
> @@ -134,6 +186,14 @@ void run_test(char *desc, int hpages, int bpages, int
> pool_nr, int expect_diff)
>
> void cleanup(void)
> {
> + int i;
> +
> + /* Clean up any allocated shmids */
> + for (i = 0; i < NR_SLOTS; i++)
> + if (map_id[i] > 0)
> + shmctl(map_id[i], IPC_RMID, NULL);
> +
> + /* Restore the pool size. */
> if (saved_nr_hugepages >= 0)
> setup_hugetlb_pool(saved_nr_hugepages);
> }
> @@ -142,15 +202,15 @@ int main(int argc, char **argv)
> {
> test_init(argc, argv);
> check_must_be_root();
> - check_free_huge_pages(POOL_SIZE);
> - saved_nr_hugepages = read_meminfo("HugePages_Total:");
> + local_check_free_huge_pages(POOL_SIZE);
> + saved_nr_hugepages = local_read_meminfo("HugePages_Total:");
>
> /*
> * We cannot call check_hugepagesize because we are not linked to
> * libhugetlbfs. This is a bit hacky but we are depending on earlier
> * tests failing to catch when this wouldn't work
> */
> - hpage_size = read_meminfo("Hugepagesize:") * 1024;
> + hpage_size = local_read_meminfo("Hugepagesize:") * 1024;
> bpage_size = getpagesize();
>
> /* Run the test with small pages */
Acked-by; Mel Gorman <[EMAIL PROTECTED]>
--
Mel Gorman
Part-time Phd Student Linux Technology Center
University of Limerick IBM Dublin Software Lab
-------------------------------------------------------------------------
This SF.Net email is sponsored by the Moblin Your Move Developer's challenge
Build the coolest Linux based applications with Moblin SDK & win great prizes
Grand prize is a trip for two to an Open Source event anywhere in the world
http://moblin-contest.org/redirect.php?banner_id=100&url=/
_______________________________________________
Libhugetlbfs-devel mailing list
Libhugetlbfs-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/libhugetlbfs-devel
