From: Neeraj Singh <neerajsi@xxxxxxxxxxxxx>
The unpack-objects functionality is used by fetch, push, and fast-import
to turn the transfered data into object database entries when there are
fewer objects than the 'unpacklimit' setting.
By enabling an odb-transaction when unpacking objects, we can take advantage
of batched fsyncs.
Here are some performance numbers to justify batch mode for
unpack-objects, collected on a WSL2 Ubuntu VM.
Fsync Mode | Time for 90 objects (ms)
-------------------------------------
Off | 170
On,fsync | 760
On,batch | 230
Note that the default unpackLimit is 100 objects, so there's a 3x
benefit in the worst case. The non-batch mode fsync scales linearly
with the number of objects, so there are significant benefits even with
smaller numbers of objects.
Signed-off-by: Neeraj Singh <neerajsi@xxxxxxxxxxxxx>
---
builtin/unpack-objects.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/builtin/unpack-objects.c b/builtin/unpack-objects.c
index dbeb0680a58..56d05e2725d 100644
--- a/builtin/unpack-objects.c
+++ b/builtin/unpack-objects.c
@@ -1,5 +1,6 @@
#include "builtin.h"
#include "cache.h"
+#include "bulk-checkin.h"
#include "config.h"
#include "object-store.h"
#include "object.h"
@@ -503,10 +504,12 @@ static void unpack_all(void)
if (!quiet)
progress = start_progress(_("Unpacking objects"), nr_objects);
CALLOC_ARRAY(obj_list, nr_objects);
+ begin_odb_transaction();
for (i = 0; i < nr_objects; i++) {
unpack_one(i);
display_progress(progress, i + 1);
}
+ end_odb_transaction();
stop_progress(&progress);
if (delta_list)
--
gitgitgadget
