io_u: don't add slat samples if we are in ramp time

[fio.git] / filesetup.c

diff --git a/filesetup.c b/filesetup.c
index 3217e4f3080cad0e782fc22e302304e49ae6531e..793b08d07549c895944f406e7afcdb7d7765e840 100644 (file)
--- a/filesetup.c
+++ b/filesetup.c
@@ -130,6 +130,9 @@ static int extend_file(struct thread_data *td, struct fio_file *f)
        }
 #endif /* CONFIG_POSIX_FALLOCATE */
 
+       /*
+        * If our jobs don't require regular files initially, we're done.
+        */
        if (!new_layout)
                goto done;
 
@@ -381,6 +384,10 @@ static int get_file_size(struct thread_data *td, struct fio_file *f)
                return 1; /* avoid offset extends end error message */
        }
 
+       /*
+        * Leave ->real_file_size with 0 since it could be expectation
+        * of initial setup for regular files.
+        */
        if (ret)
                return ret;
 
@@ -659,6 +666,10 @@ open_again:
        return 0;
 }
 
+/*
+ * This function i.e. get_file_size() is the default .get_file_size
+ * implementation of majority of I/O engines.
+ */
 int generic_get_file_size(struct thread_data *td, struct fio_file *f)
 {
        return get_file_size(td, f);
@@ -686,6 +697,13 @@ static int get_file_sizes(struct thread_data *td)
                        clear_error(td);
                }
 
+               /*
+                * There are corner cases where we end up with -1 for
+                * ->real_file_size due to unsupported file type, etc.
+                * We then just set to size option value divided by number
+                * of files, similar to the way file ->io_size is set.
+                * stat(2) failure doesn't set ->real_file_size to -1.
+                */
                if (f->real_file_size == -1ULL && td->o.size)
                        f->real_file_size = td->o.size / td->o.nr_files;
        }
@@ -802,7 +820,9 @@ int setup_files(struct thread_data *td)
                goto done;
 
        /*
-        * if ioengine defines a setup() method, it's responsible for
+        * Find out physical size of files or devices for this thread,
+        * before we determine I/O size and range of our targets.
+        * If ioengine defines a setup() method, it's responsible for
         * opening the files and setting f->real_file_size to indicate
         * the valid range for that file.
         */
@@ -843,7 +863,7 @@ int setup_files(struct thread_data *td)
 
        /*
         * Calculate per-file size and potential extra size for the
-        * first files, if needed.
+        * first files, if needed (i.e. if we don't have a fixed size).
         */
        if (!o->file_size_low && o->nr_files) {
                uint64_t all_fs;
@@ -865,9 +885,17 @@ int setup_files(struct thread_data *td)
        for_each_file(td, f, i) {
                f->file_offset = get_start_offset(td, f);
 
+               /*
+                * Update ->io_size depending on options specified.
+                * ->file_size_low being 0 means filesize option isn't set.
+                * Non zero ->file_size_low equals ->file_size_high means
+                * filesize option is set in a fixed size format.
+                * Non zero ->file_size_low not equals ->file_size_high means
+                * filesize option is set in a range format.
+                */
                if (!o->file_size_low) {
                        /*
-                        * no file size range given, file size is equal to
+                        * no file size or range given, file size is equal to
                         * total size divided by number of files. If that is
                         * zero, set it to the real file size. If the size
                         * doesn't divide nicely with the min blocksize,
@@ -950,7 +978,9 @@ int setup_files(struct thread_data *td)
        }
 
        /*
-        * See if we need to extend some files
+        * See if we need to extend some files, typically needed when our
+        * target regular files don't exist yet, but our jobs require them
+        * initially due to read I/Os.
         */
        if (need_extend) {
                temp_stall_ts = 1;