Add support for runtime log compression
If log_compression=64M is specified, fio will "bite" off chunks of
the IO logs and runtime compress them with zlib. This can greatly
reduce the amount of memory required to do iops/bw/lat logging of
a run, at the cost of using some background CPU for the compression.
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/stat.c b/stat.c
index 58744a8..ccf08a6 100644
--- a/stat.c
+++ b/stat.c
@@ -1565,7 +1565,7 @@
enum fio_ddir ddir, unsigned int bs,
unsigned long t, uint64_t offset)
{
- const int nr_samples = iolog->nr_samples;
+ uint64_t nr_samples = iolog->nr_samples;
struct io_sample *s;
if (iolog->disabled)
@@ -1579,14 +1579,24 @@
void *new_log;
new_size = 2 * iolog->max_samples * log_entry_sz(iolog);
- new_log = realloc(iolog->log, new_size);
- if (!new_log) {
- log_err("fio: failed extending iolog! Will stop logging.\n");
- iolog->disabled = 1;
- return;
+
+ if (iolog->log_gz && (new_size > iolog->log_gz)) {
+ if (iolog_flush(iolog, 0)) {
+ log_err("fio: failed flushing iolog! Will stop logging.\n");
+ iolog->disabled = 1;
+ return;
+ }
+ nr_samples = iolog->nr_samples;
+ } else {
+ new_log = realloc(iolog->log, new_size);
+ if (!new_log) {
+ log_err("fio: failed extending iolog! Will stop logging.\n");
+ iolog->disabled = 1;
+ return;
+ }
+ iolog->log = new_log;
+ iolog->max_samples <<= 1;
}
- iolog->log = new_log;
- iolog->max_samples <<= 1;
}
s = get_sample(iolog, nr_samples);