eal/linux: allow hugetlbfs sub-directories

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: DPDK might not be the only user of hugepages, and
shouldn't assume it owns an entire mountpoint. For example, if I have
/dev/hugepages/myapp, and /dev/hugepages/dpdk, I should be able to
specify:

--huge-dir=/dev/hugepages/dpdk/

and have DPDK only use that sub-directory.

Fix the implementation to allow a sub-directory within a suitable
hugetlbfs mountpoint to be specified, preferring the closest match.

Signed-off-by: John Levon <john.levon@nutanix.com>
Acked-by: Dmitry Kozlyuk <dmitry.kozliuk@gmail.com>
Reviewed-by: David Marchand <david.marchand@redhat.com>

diff --git a/app/test/test_eal_flags.c b/app/test/test_eal_flags.c
index b4880ee..1d18a0b 100644 (file)
--- a/app/test/test_eal_flags.c
+++ b/app/test/test_eal_flags.c
@@ -14,8 +14,9 @@
 #include <errno.h>
 #include <unistd.h>
 #include <dirent.h>
-#include <sys/wait.h>
 #include <sys/file.h>
+#include <sys/stat.h>
+#include <sys/wait.h>
 #include <limits.h>
 #include <fcntl.h>
 
@@ -800,6 +801,9 @@ static int
 test_misc_flags(void)
 {
        char hugepath[PATH_MAX] = {0};
+       char hugepath_dir[PATH_MAX] = {0};
+       char hugepath_dir2[PATH_MAX] = {0};
+       char hugepath_dir3[PATH_MAX] = {0};
 #ifdef RTE_EXEC_ENV_FREEBSD
        /* BSD target doesn't support prefixes at this point */
        const char * prefix = "";
@@ -810,6 +814,7 @@ test_misc_flags(void)
        FILE * hugedir_handle = NULL;
        char line[PATH_MAX] = {0};
        unsigned i, isempty = 1;
+
        if (get_current_prefix(tmp, sizeof(tmp)) == NULL) {
                printf("Error - unable to get current prefix!\n");
                return -1;
@@ -849,6 +854,20 @@ test_misc_flags(void)
        }
 #endif
 
+       snprintf(hugepath_dir, sizeof(hugepath_dir), "%s/dpdk.missing", hugepath);
+       snprintf(hugepath_dir2, sizeof(hugepath_dir2), "%s/dpdk.dir", hugepath);
+
+       if (mkdir(hugepath_dir2, 0700) != 0 && errno != EEXIST) {
+               printf("Error - failed to mkdir(%s)\n", hugepath_dir2);
+               return -1;
+       }
+
+       snprintf(hugepath_dir3, sizeof(hugepath_dir3), "%s/dpdk.dir/sub", hugepath);
+
+       if (mkdir(hugepath_dir3, 0700) != 0 && errno != EEXIST) {
+               printf("Error - failed to mkdir(%s)\n", hugepath_dir3);
+               goto fail;
+       }
 
        /* check that some general flags don't prevent things from working.
         * All cases, apart from the first, app should run.
@@ -881,60 +900,66 @@ test_misc_flags(void)
        /* With invalid --huge-dir */
        const char *argv9[] = {prgname, "-m", DEFAULT_MEM_SIZE,
                        "--file-prefix=hugedir", "--huge-dir", "invalid"};
+       /* With invalid --huge-dir sub-directory */
+       const char *argv10[] = {prgname, "-m", DEFAULT_MEM_SIZE,
+                       "--file-prefix=hugedir", "--huge-dir", hugepath_dir};
+       /* With valid --huge-dir sub-directory */
+       const char *argv11[] = {prgname, "-m", DEFAULT_MEM_SIZE,
+                       "--file-prefix=hugedir", "--huge-dir", hugepath_dir2};
        /* Secondary process with invalid --huge-dir (should run as flag has no
         * effect on secondary processes) */
-       const char *argv10[] = {prgname, prefix, mp_flag,
+       const char *argv12[] = {prgname, prefix, mp_flag,
                        "--huge-dir", "invalid"};
 
        /* try running with base-virtaddr param */
-       const char *argv11[] = {prgname, "--file-prefix=virtaddr",
+       const char *argv13[] = {prgname, "--file-prefix=virtaddr",
                        "--base-virtaddr=0x12345678"};
 
        /* try running with --vfio-intr INTx flag */
-       const char *argv12[] = {prgname, "--file-prefix=intr",
+       const char *argv14[] = {prgname, "--file-prefix=intr",
                        "--vfio-intr=legacy"};
 
        /* try running with --vfio-intr MSI flag */
-       const char *argv13[] = {prgname, "--file-prefix=intr",
+       const char *argv15[] = {prgname, "--file-prefix=intr",
                        "--vfio-intr=msi"};
 
        /* try running with --vfio-intr MSI-X flag */
-       const char *argv14[] = {prgname, "--file-prefix=intr",
+       const char *argv16[] = {prgname, "--file-prefix=intr",
                        "--vfio-intr=msix"};
 
        /* try running with --vfio-intr invalid flag */
-       const char *argv15[] = {prgname, "--file-prefix=intr",
+       const char *argv17[] = {prgname, "--file-prefix=intr",
                        "--vfio-intr=invalid"};
 
        /* With process type as auto-detect */
-       const char * const argv16[] = {prgname, "--file-prefix=auto",
+       const char * const argv18[] = {prgname, "--file-prefix=auto",
                        "--proc-type=auto"};
 
        /* With process type as auto-detect with no-shconf */
-       const char * const argv17[] = {prgname, "--proc-type=auto",
+       const char * const argv19[] = {prgname, "--proc-type=auto",
                        no_shconf, nosh_prefix, no_huge};
 
        /* With process type as --create-uio-dev flag */
-       const char * const argv18[] = {prgname, "--file-prefix=uiodev",
+       const char * const argv20[] = {prgname, "--file-prefix=uiodev",
                        "--create-uio-dev"};
 
        /* run all tests also applicable to FreeBSD first */
 
        if (launch_proc(argv0) == 0) {
                printf("Error - process ran ok with invalid flag\n");
-               return -1;
+               goto fail;
        }
        if (launch_proc(argv1) != 0) {
                printf("Error - process did not run ok with --no-pci flag\n");
-               return -1;
+               goto fail;
        }
        if (launch_proc(argv2) != 0) {
                printf("Error - process did not run ok with -v flag\n");
-               return -1;
+               goto fail;
        }
        if (launch_proc(argv6) != 0) {
                printf("Error - process did not run ok with --no-shconf flag\n");
-               return -1;
+               goto fail;
        }
 
 #ifdef RTE_EXEC_ENV_FREEBSD
@@ -944,73 +969,88 @@ test_misc_flags(void)
 
        if (launch_proc(argv3) != 0) {
                printf("Error - process did not run ok with --syslog flag\n");
-               return -1;
+               goto fail;
        }
        if (launch_proc(argv4) == 0) {
                printf("Error - process run ok with empty --syslog flag\n");
-               return -1;
+               goto fail;
        }
        if (launch_proc(argv5) == 0) {
                printf("Error - process run ok with invalid --syslog flag\n");
-               return -1;
+               goto fail;
        }
        if (launch_proc(argv7) != 0) {
                printf("Error - process did not run ok with --huge-dir flag\n");
-               return -1;
+               goto fail;
        }
        if (launch_proc(argv8) == 0) {
                printf("Error - process run ok with empty --huge-dir flag\n");
-               return -1;
+               goto fail;
        }
        if (launch_proc(argv9) == 0) {
                printf("Error - process run ok with invalid --huge-dir flag\n");
-               return -1;
+               goto fail;
        }
-       if (launch_proc(argv10) != 0) {
-               printf("Error - secondary process did not run ok with invalid --huge-dir flag\n");
-               return -1;
+       if (launch_proc(argv10) == 0) {
+               printf("Error - process run ok with invalid --huge-dir sub-dir flag\n");
+               goto fail;
        }
        if (launch_proc(argv11) != 0) {
-               printf("Error - process did not run ok with --base-virtaddr parameter\n");
-               return -1;
+               printf("Error - process did not run ok with --huge-dir subdir flag\n");
+               goto fail;
        }
        if (launch_proc(argv12) != 0) {
+               printf("Error - secondary process did not run ok with invalid --huge-dir flag\n");
+               goto fail;
+       }
+       if (launch_proc(argv13) != 0) {
+               printf("Error - process did not run ok with --base-virtaddr parameter\n");
+               goto fail;
+       }
+       if (launch_proc(argv14) != 0) {
                printf("Error - process did not run ok with "
                                "--vfio-intr INTx parameter\n");
-               return -1;
+               goto fail;
        }
-       if (launch_proc(argv13) != 0) {
+       if (launch_proc(argv15) != 0) {
                printf("Error - process did not run ok with "
                                "--vfio-intr MSI parameter\n");
-               return -1;
+               goto fail;
        }
-       if (launch_proc(argv14) != 0) {
+       if (launch_proc(argv16) != 0) {
                printf("Error - process did not run ok with "
                                "--vfio-intr MSI-X parameter\n");
-               return -1;
+               goto fail;
        }
-       if (launch_proc(argv15) == 0) {
+       if (launch_proc(argv17) == 0) {
                printf("Error - process run ok with "
                                "--vfio-intr invalid parameter\n");
-               return -1;
+               goto fail;
        }
-       if (launch_proc(argv16) != 0) {
+       if (launch_proc(argv18) != 0) {
                printf("Error - process did not run ok with "
                                "--proc-type as auto parameter\n");
-               return -1;
+               goto fail;
        }
-       if (launch_proc(argv17) != 0) {
+       if (launch_proc(argv19) != 0) {
                printf("Error - process did not run ok with "
                                "--proc-type and --no-shconf parameter\n");
-               return -1;
+               goto fail;
        }
-       if (launch_proc(argv18) != 0) {
+       if (launch_proc(argv20) != 0) {
                printf("Error - process did not run ok with "
                                "--create-uio-dev parameter\n");
-               return -1;
+               goto fail;
        }
 
+       rmdir(hugepath_dir3);
+       rmdir(hugepath_dir2);
        return 0;
+
+fail:
+       rmdir(hugepath_dir3);
+       rmdir(hugepath_dir2);
+       return -1;
 }
 
 static int

diff --git a/doc/guides/linux_gsg/linux_eal_parameters.rst b/doc/guides/linux_gsg/linux_eal_parameters.rst
index bd3977c..74df261 100644 (file)
--- a/doc/guides/linux_gsg/linux_eal_parameters.rst
+++ b/doc/guides/linux_gsg/linux_eal_parameters.rst
@@ -81,7 +81,8 @@ Memory-related options
 
 *   ``--huge-dir <path to hugetlbfs directory>``
 
-    Use specified hugetlbfs directory instead of autodetected ones.
+    Use specified hugetlbfs directory instead of autodetected ones. This can be
+    a sub-directory within a hugetlbfs mountpoint.
 
 *   ``--huge-unlink``
 

diff --git a/doc/guides/rel_notes/release_21_11.rst b/doc/guides/rel_notes/release_21_11.rst
index 54718ff..f643a61 100644 (file)
--- a/doc/guides/rel_notes/release_21_11.rst
+++ b/doc/guides/rel_notes/release_21_11.rst
@@ -62,6 +62,11 @@ New Features
   * Added bus-level parsing of the devargs syntax.
   * Kept compatibility with the legacy syntax as parsing fallback.
 
+* **Updated EAL hugetlbfs mount handling for Linux.**
+
+  * Modified to allow ``--huge-dir`` option to specify a sub-directory
+    within a hugetlbfs mountpoint.
+
 * **Added new RSS offload types for IPv4/L4 checksum in RSS flow.**
 
   Added macros ETH_RSS_IPV4_CHKSUM and ETH_RSS_L4_CHKSUM, now IPv4 and

diff --git a/lib/eal/linux/eal_hugepage_info.c b/lib/eal/linux/eal_hugepage_info.c
index d97792c..9fb0e96 100644 (file)
--- a/lib/eal/linux/eal_hugepage_info.c
+++ b/lib/eal/linux/eal_hugepage_info.c
@@ -213,10 +213,19 @@ get_hugepage_dir(uint64_t hugepage_sz, char *hugedir, int len)
        const size_t pagesize_opt_len = sizeof(pagesize_opt) - 1;
        const char split_tok = ' ';
        char *splitstr[_FIELDNAME_MAX];
+       char found[PATH_MAX] = "";
        char buf[BUFSIZ];
-       int retval = -1;
        const struct internal_config *internal_conf =
                eal_get_internal_configuration();
+       struct stat st;
+
+       /*
+        * If the specified dir doesn't exist, we can't match it.
+        */
+       if (internal_conf->hugepage_dir != NULL &&
+               stat(internal_conf->hugepage_dir, &st) != 0) {
+               return -1;
+       }
 
        FILE *fd = fopen(proc_mounts, "r");
        if (fd == NULL)
@@ -226,42 +235,66 @@ 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 *pagesz_str;
+
                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)
+               if (strncmp(splitstr[FSTYPE], hugetlbfs_str, htlbfs_str_len) != 0)
                        continue;
 
-               if (strncmp(splitstr[FSTYPE], hugetlbfs_str, htlbfs_str_len) == 0){
-                       const char *pagesz_str = strstr(splitstr[OPTIONS], pagesize_opt);
+               pagesz_str = strstr(splitstr[OPTIONS], pagesize_opt);
 
-                       /* if no explicit page size, the default page size is compared */
-                       if (pagesz_str == NULL){
-                               if (hugepage_sz == default_size){
-                                       strlcpy(hugedir, splitstr[MOUNTPT], len);
-                                       retval = 0;
-                                       break;
-                               }
-                       }
-                       /* there is an explicit page size, so check it */
-                       else {
-                               uint64_t pagesz = rte_str_to_size(&pagesz_str[pagesize_opt_len]);
-                               if (pagesz == hugepage_sz) {
-                                       strlcpy(hugedir, splitstr[MOUNTPT], len);
-                                       retval = 0;
-                                       break;
-                               }
-                       }
-               } /* end if strncmp hugetlbfs */
+               /* if no explicit page size, the default page size is compared */
+               if (pagesz_str == NULL) {
+                       if (hugepage_sz != default_size)
+                               continue;
+               }
+               /* there is an explicit page size, so check it */
+               else {
+                       uint64_t pagesz = rte_str_to_size(&pagesz_str[pagesize_opt_len]);
+                       if (pagesz != hugepage_sz)
+                               continue;
+               }
+
+               /*
+                * If no --huge-dir option has been given, we're done.
+                */
+               if (internal_conf->hugepage_dir == NULL) {
+                       strlcpy(found, splitstr[MOUNTPT], len);
+                       break;
+               }
+
+               /*
+                * Ignore any mount that doesn't contain the --huge-dir
+                * directory.
+                */
+               if (strncmp(internal_conf->hugepage_dir, splitstr[MOUNTPT],
+                       strlen(splitstr[MOUNTPT])) != 0) {
+                       continue;
+               }
+
+               /*
+                * We found a match, but only prefer it if it's a longer match
+                * (so /mnt/1 is preferred over /mnt for matching /mnt/1/2)).
+                */
+               if (strlen(splitstr[MOUNTPT]) > strlen(found))
+                       strlcpy(found, splitstr[MOUNTPT], len);
        } /* end while fgets */
 
        fclose(fd);
-       return retval;
+
+       if (found[0] != '\0') {
+               /* If needed, return the requested dir, not the mount point. */
+               strlcpy(hugedir, internal_conf->hugepage_dir != NULL ?
+                       internal_conf->hugepage_dir : found, len);
+               return 0;
+       }
+
+       return -1;
 }
 
 /*