From: David Turner <dturner@twopensource.com>
To: git@vger.kernel.org, pclouds@gmail.com
Cc: David Turner <dturner@twopensource.com>
Subject: [PATCH v7 02/19] read-cache: allow to keep mmap'd memory after reading
Date: Fri, 29 Apr 2016 21:01:56 -0400 [thread overview]
Message-ID: <1461978133-13966-3-git-send-email-dturner@twopensource.com> (raw)
In-Reply-To: <1461978133-13966-1-git-send-email-dturner@twopensource.com>
From: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
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@gmail.com>
Signed-off-by: David Turner <dturner@twopensource.com>
---
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
next prev parent reply other threads:[~2016-04-30 1:02 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-30 1:01 [PATCH v7 00/19] index-helper/watchman David Turner
2016-04-30 1:01 ` [PATCH v7 01/19] read-cache.c: fix constness of verify_hdr() David Turner
2016-04-30 1:01 ` David Turner [this message]
2016-04-30 1:01 ` [PATCH v7 03/19] index-helper: new daemon for caching index and related stuff David Turner
2016-04-30 1:01 ` [PATCH v7 04/19] index-helper: add --strict David Turner
2016-04-30 1:01 ` [PATCH v7 05/19] index-helper: log warnings David Turner
2016-04-30 1:02 ` [PATCH v7 06/19] daemonize(): set a flag before exiting the main process David Turner
2016-04-30 1:02 ` [PATCH v7 07/19] index-helper: add --detach David Turner
2016-04-30 1:02 ` [PATCH v7 08/19] read-cache: add watchman 'WAMA' extension David Turner
2016-04-30 1:02 ` [PATCH v7 09/19] Add watchman support to reduce index refresh cost David Turner
2016-04-30 1:02 ` [PATCH v7 10/19] index-helper: use watchman to avoid refreshing index with lstat() David Turner
2016-04-30 1:02 ` [PATCH v7 11/19] update-index: enable/disable watchman support David Turner
2016-04-30 1:02 ` [PATCH v7 12/19] unpack-trees: preserve index extensions David Turner
2016-04-30 1:02 ` [PATCH v7 13/19] watchman: add a config option to enable the extension David Turner
2016-04-30 1:02 ` [PATCH v7 14/19] index-helper: kill mode David Turner
2016-04-30 1:02 ` [PATCH v7 15/19] index-helper: don't run if already running David Turner
2016-04-30 1:02 ` [PATCH v7 16/19] index-helper: autorun mode David Turner
2016-04-30 1:02 ` [PATCH v7 17/19] index-helper: optionally automatically run David Turner
2016-04-30 1:02 ` [PATCH v7 18/19] Add tracing to measure where most of the time is spent David Turner
2016-04-30 1:02 ` [PATCH v7 19/19] untracked-cache: config option David Turner
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