Hi,
On 12/11/2015 02:10, Jianfeng Tan wrote:
> This patch enables calculating space left in a hugetlbfs.
> There are three sources to get the information: 1. from
> sysfs; 2. from option size specified when mount; 3. use
> statfs. We should use the minimum one of these three sizes.
We could improve the message by stating the current issue (when the
hugetlbfs mount specifies size= option), then how the patch deals
with the problem and also outstanding issues.
> Signed-off-by: Jianfeng Tan <jianfeng.tan at intel.com>
> ---
> Changes in v2:
> - reword title
> - fix compiler error of v1
>
> lib/librte_eal/linuxapp/eal/eal_hugepage_info.c | 85
> ++++++++++++++++++++++++-
> 1 file changed, 84 insertions(+), 1 deletion(-)
>
> diff --git a/lib/librte_eal/linuxapp/eal/eal_hugepage_info.c
> b/lib/librte_eal/linuxapp/eal/eal_hugepage_info.c
> index 18858e2..8305a58 100644
> --- a/lib/librte_eal/linuxapp/eal/eal_hugepage_info.c
> +++ b/lib/librte_eal/linuxapp/eal/eal_hugepage_info.c
> @@ -44,6 +44,8 @@
> #include <unistd.h>
> #include <errno.h>
> #include <sys/queue.h>
> +#include <sys/vfs.h>
> +#include <mntent.h>
>
> #include <rte_memory.h>
> #include <rte_memzone.h>
> @@ -189,6 +191,70 @@ get_hugepage_dir(uint64_t hugepage_sz)
> return retval;
> }
>
> +/* Caller to make sure this mnt_dir exist
> + */
> +static uint64_t
> +get_hugetlbfs_mount_size(const char *mnt_dir)
> +{
> + char *start, *end, *opt_size;
> + struct mntent *ent;
> + uint64_t size;
> + FILE *f;
> + int len;
> +
> + f = setmntent("/proc/mounts", "r");
> + if (f == NULL) {
> + RTE_LOG(ERR, EAL, "setmntent() error: %s\n",
> + strerror(errno));
> + return 0;
> + }
> + while (NULL != (ent = getmntent(f))) {
> + if (!strcmp(ent->mnt_dir, mnt_dir))
> + break;
> + }
> +
> + start = hasmntopt(ent, "size");
> + if (start == NULL) {
> + RTE_LOG(DEBUG, EAL, "option size not specified for %s\n",
> + mnt_dir);
> + size = 0;
> + goto end;
> + }
> + start += strlen("size=");
> + end = strstr(start, ",");
> + if (end != NULL)
> + len = end - start;
> + else
> + len = strlen(start);
> + opt_size = strndup(start, len);
> + size = rte_str_to_size(opt_size);
> + free(opt_size);
> +
> +end:
> + endmntent(f);
> + return size;
> +}
> +
The function above is very similar to get_hugepage_dir, ie. open and parse
/proc/mounts.
I think it would be better to have a more generic function that retrieves
all needed info from /proc/mounts.
> +/* Caller to make sure this mount has option size
> + * so that statfs is not zero.
> + */
> +static uint64_t
> +get_hugetlbfs_free_size(const char *mnt_dir)
> +{
> + int r;
> + struct statfs stats;
> +
> + r = statfs(mnt_dir, &stats);
> + if (r != 0) {
> + RTE_LOG(ERR, EAL, "statfs() error: %s\n",
> + strerror(errno));
> + return 0;
> + }
> +
> + return stats.f_bfree * stats.f_bsize;
> +}
> +
> +
> /*
> * Clear the hugepage directory of whatever hugepage files
> * there are. Checks if the file is locked (i.e.
> @@ -329,9 +395,26 @@ eal_hugepage_info_init(void)
> if (clear_hugedir(hpi->hugedir) == -1)
> break;
>
> + /* there are three souces of how much space left in a
> + * hugetlbfs dir.
> + */
> + uint64_t sz_left, sz_sysfs, sz_option, sz_statfs;
> +
> + sz_sysfs = get_num_hugepages(dirent->d_name) *
> + hpi->hugepage_sz;
> + sz_left = sz_sysfs;
> + sz_option = get_hugetlbfs_mount_size(hpi->hugedir);
> + if (sz_option) {
> + sz_statfs = get_hugetlbfs_free_size(hpi->hugedir);
> + sz_left = RTE_MIN(sz_sysfs, sz_statfs);
> + RTE_LOG(INFO, EAL, "sz_sysfs: %"PRIu64", sz_option: "
> + "%"PRIu64", sz_statfs: %"PRIu64"\n",
> + sz_sysfs, sz_option, sz_statfs);
> + }
> +
> /* for now, put all pages into socket 0,
> * later they will be sorted */
> - hpi->num_pages[0] = get_num_hugepages(dirent->d_name);
> + hpi->num_pages[0] = sz_left / hpi->hugepage_sz;
>
> #ifndef RTE_ARCH_64
> /* for 32-bit systems, limit number of hugepages to
A couple more things:
- Update release-notes and/or relevant doc about improved detection of
free hugepages
- Update the status of previous/old patches in patchwork
Sergio
