From: Nguyễn Thái Ngọc Duy <pclouds@xxxxxxxxx>
Later, we will introduce git index-helper to share this memory with
other git processes.
We only unmap it when we discard the index (although the kernel may of
course choose to page it out).
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@xxxxxxxxx>
Signed-off-by: David Turner <dturner@xxxxxxxxxxxxxxxx>
---
cache.h | 3 +++
read-cache.c | 13 ++++++++++++-
2 files changed, 15 insertions(+), 1 deletion(-)
diff --git a/cache.h b/cache.h
index b829410..4180e2b 100644
--- a/cache.h
+++ b/cache.h
@@ -333,11 +333,14 @@ struct index_state {
struct split_index *split_index;
struct cache_time timestamp;
unsigned name_hash_initialized : 1,
+ keep_mmap : 1,
initialized : 1;
struct hashmap name_hash;
struct hashmap dir_hash;
unsigned char sha1[20];
struct untracked_cache *untracked;
+ void *mmap;
+ size_t mmap_size;
};
extern struct index_state the_index;
diff --git a/read-cache.c b/read-cache.c
index 16cc487..3cb0ec3 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -1574,6 +1574,10 @@ int do_read_index(struct index_state *istate, const char *path, int must_exist)
mmap = xmmap(NULL, mmap_size, PROT_READ, MAP_PRIVATE, fd, 0);
if (mmap == MAP_FAILED)
die_errno("unable to map index file");
+ if (istate->keep_mmap) {
+ istate->mmap = mmap;
+ istate->mmap_size = mmap_size;
+ }
close(fd);
hdr = mmap;
@@ -1626,11 +1630,13 @@ int do_read_index(struct index_state *istate, const char *path, int must_exist)
src_offset += 8;
src_offset += extsize;
}
- munmap(mmap, mmap_size);
+ if (!istate->keep_mmap)
+ munmap(mmap, mmap_size);
return istate->cache_nr;
unmap:
munmap(mmap, mmap_size);
+ istate->mmap = NULL;
die("index file corrupt");
}
@@ -1655,6 +1661,7 @@ int read_index_from(struct index_state *istate, const char *path)
discard_index(split_index->base);
else
split_index->base = xcalloc(1, sizeof(*split_index->base));
+ split_index->base->keep_mmap = istate->keep_mmap;
ret = do_read_index(split_index->base,
git_path("sharedindex.%s",
sha1_to_hex(split_index->base_sha1)), 1);
@@ -1698,6 +1705,10 @@ int discard_index(struct index_state *istate)
free(istate->cache);
istate->cache = NULL;
istate->cache_alloc = 0;
+ if (istate->keep_mmap && istate->mmap) {
+ munmap(istate->mmap, istate->mmap_size);
+ istate->mmap = NULL;
+ }
discard_split_index(istate);
free_untracked_cache(istate->untracked);
istate->untracked = NULL;
--
2.4.2.767.g62658d5-twtrsrc
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