Add support for reserved keywords

Currently $pagesize, $mb_memory, and $ncpus are supported.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

diff --git a/HOWTO b/HOWTO
index aec00e84e548f1c9d65952e73803d8fcb5df53e9..662ebe32acf2e10c1956f8f768171da2f92de244 100644 (file)
--- a/HOWTO
+++ b/HOWTO
@@ -158,6 +158,9 @@ specify:
 
 $ fio --name=random-writers --ioengine=libaio --iodepth=4 --rw=randwrite --bs=32k --direct=0 --size=64m --numjobs=4
 
+4.1 Environment variables
+-------------------------
+
 fio also supports environment variable expansion in job files. Any
 substring of the form "${VARNAME}" as part of an option value (in other
 words, on the right of the `='), will be expanded to the value of the
@@ -188,6 +191,20 @@ numjobs=4
 fio ships with a few example job files, you can also look there for
 inspiration.
 
+4.2 Reserved keywords
+---------------------
+
+Additionally, fio has a set of reserved keywords that will be replaced
+internally with the appropriate value. Those keywords are:
+
+$pagesize      The architecture page size of the running system
+$mb_memory     Megabytes of total memory in the system
+$ncpus         Number of online available CPUs
+
+These can be used on the command line or in the job file, and will be
+automatically substituted with the current system values when the job
+is run.
+
 
 5.0 Detailed list of parameters
 -------------------------------

diff --git a/fio.c b/fio.c
index 7ad1b57219cb646926cbc65a49cf22143b721e4b..dfd15e0f5db1e943a9aec595454cf1f601e97fea 100644 (file)
--- a/fio.c
+++ b/fio.c
@@ -1618,12 +1618,6 @@ int main(int argc, char *argv[])
        if (!getenv("LC_NUMERIC"))
                setlocale(LC_NUMERIC, "en_US");
 
-       if (parse_options(argc, argv))
-               return 1;
-
-       if (!thread_number)
-               return 0;
-
        ps = sysconf(_SC_PAGESIZE);
        if (ps < 0) {
                log_err("Failed to get page size\n");
@@ -1633,6 +1627,14 @@ int main(int argc, char *argv[])
        page_size = ps;
        page_mask = ps - 1;
 
+       fio_keywords_init();
+
+       if (parse_options(argc, argv))
+               return 1;
+
+       if (!thread_number)
+               return 0;
+
        if (write_bw_log) {
                setup_log(&agg_io_log[DDIR_READ]);
                setup_log(&agg_io_log[DDIR_WRITE]);

diff --git a/fio.h b/fio.h
index 56d3101d94f1d7cf9e720abaf4a700dba83f309b..049692d65e03783d3dcd934f2225c50482e7a6cb 100644 (file)
--- a/fio.h
+++ b/fio.h
@@ -511,6 +511,7 @@ extern int in_ramp_time(struct thread_data *);
  */
 extern int __must_check parse_options(int, char **);
 extern int fio_options_parse(struct thread_data *, char **, int);
+extern void fio_keywords_init(void);
 extern int fio_cmd_option_parse(struct thread_data *, const char *, char *);
 extern void fio_fill_default_options(struct thread_data *);
 extern int fio_show_option_help(const char *);

diff --git a/options.c b/options.c
index b7262a7ff4eefb3be41413308e8a88374a27b863..e085f6ce9c075acd44c6778daee312abda4343e6 100644 (file)
--- a/options.c
+++ b/options.c
@@ -1698,14 +1698,102 @@ void fio_options_dup_and_init(struct option *long_options)
        }
 }
 
+struct fio_keyword {
+       const char *word;
+       const char *desc;
+       char *replace;
+};
+
+static struct fio_keyword fio_keywords[] = {
+       {
+               .word   = "$pagesize",
+               .desc   = "Page size in the system",
+       },
+       {
+               .word   = "$mb_memory",
+               .desc   = "Megabytes of memory online",
+       },
+       {
+               .word   = "$ncpus",
+               .desc   = "Number of CPUs online in the system",
+       },
+       {
+               .word   = NULL,
+       },
+};
+
+void fio_keywords_init(void)
+{
+       unsigned long mb_memory;
+       char buf[128];
+       long l;
+
+       sprintf(buf, "%lu", page_size);
+       fio_keywords[0].replace = strdup(buf);
+
+       l = sysconf(_SC_PHYS_PAGES);
+       mb_memory = l * (page_size / 1024UL);
+       sprintf(buf, "%lu", mb_memory);
+       fio_keywords[1].replace = strdup(buf);
+
+       l = sysconf(_SC_NPROCESSORS_ONLN);
+       sprintf(buf, "%lu", l);
+       fio_keywords[2].replace = strdup(buf);
+}
+
+/*
+ * Look for reserved variable names and replace them with real values
+ */
+static char *fio_keyword_replace(char *opt)
+{
+       char *s;
+       int i;
+
+       for (i = 0; fio_keywords[i].word != NULL; i++) {
+               struct fio_keyword *kw = &fio_keywords[i];
+
+               while ((s = strstr(opt, kw->word)) != NULL) {
+                       char *new = malloc(strlen(opt) + 1);
+                       char *o_org = opt;
+                       int olen = s - opt;
+                       int len;
+
+                       /*
+                        * Copy part of the string before the keyword and
+                        * sprintf() the replacement after it.
+                        */
+                       memcpy(new, opt, olen);
+                       len = sprintf(new + olen, "%s", kw->replace);
+
+                       /*
+                        * If there's more in the original string, copy that
+                        * in too
+                        */
+                       opt += strlen(kw->word) + olen;
+                       if (strlen(opt))
+                               memcpy(new + olen + len, opt, opt - o_org - 1);
+
+                       /*
+                        * replace opt and free the old opt
+                        */
+                       opt = new;
+                       free(o_org);
+               }
+       }
+
+       return opt;
+}
+
 int fio_options_parse(struct thread_data *td, char **opts, int num_opts)
 {
        int i, ret;
 
        sort_options(opts, options, num_opts);
 
-       for (ret = 0, i = 0; i < num_opts; i++)
+       for (ret = 0, i = 0; i < num_opts; i++) {
+               opts[i] = fio_keyword_replace(opts[i]);
                ret |= parse_option(opts[i], options, td);
+       }
 
        return ret;
 }