2021-06-25 11:44 (UTC+0100), John Levon:
> get_hugepage_dir() was implemented in such a way that a --huge-dir option
> had to exactly match the mountpoint, but there's no reason for this
> restriction. Fix the implementation to allow a sub-directory within a
> suitable hugetlbfs mountpoint to be specified.
>
> Signed-off-by: John Levon <john.le...@nutanix.com>
> ---
> lib/eal/linux/eal_hugepage_info.c | 25 +++++++++++++++++++------
> 1 file changed, 19 insertions(+), 6 deletions(-)
>
> diff --git a/lib/eal/linux/eal_hugepage_info.c
> b/lib/eal/linux/eal_hugepage_info.c
> index d97792cad..d7e9918f8 100644
> --- a/lib/eal/linux/eal_hugepage_info.c
> +++ b/lib/eal/linux/eal_hugepage_info.c
> @@ -226,16 +226,29 @@ get_hugepage_dir(uint64_t hugepage_sz, char *hugedir,
> int len)
> default_size = get_default_hp_size();
>
> while (fgets(buf, sizeof(buf), fd)){
> + const char *dir;
> +
> if (rte_strsplit(buf, sizeof(buf), splitstr, _FIELDNAME_MAX,
> split_tok) != _FIELDNAME_MAX) {
> RTE_LOG(ERR, EAL, "Error parsing %s\n", proc_mounts);
> break; /* return NULL */
> }
>
> - /* we have a specified --huge-dir option, only examine that dir
> */
> - if (internal_conf->hugepage_dir != NULL &&
> - strcmp(splitstr[MOUNTPT],
> internal_conf->hugepage_dir) != 0)
> - continue;
> + dir = splitstr[MOUNTPT];
> +
> + /*
> + * If a --huge-dir option has been specified, only examine
> + * mounts that contain that directory, and make sure to return
> + * the directory, not the mount.
> + */
> + if (internal_conf->hugepage_dir != NULL) {
> + if (strncmp(internal_conf->hugepage_dir,
> + splitstr[MOUNTPT],
> + strlen(splitstr[MOUNTPT])) != 0)
> + continue;
> +
> + dir = internal_conf->hugepage_dir;
> + }
Suppose there are /mnt/huge and /mnt/huge-2M mounted with -o pagesize=2M.
If --huge-dir=/mnt/huge-2M is specified, this code will select /mnt/huge.
The code would be shorter with `splitstr[MOUNTPT]` -> `dir`.
