diff options
| -rw-r--r-- | Documentation/config.txt | 9 | ||||
| -rw-r--r-- | Makefile | 1 | ||||
| -rw-r--r-- | builtin-commit.c | 8 | ||||
| -rw-r--r-- | builtin-diff-files.c | 4 | ||||
| -rw-r--r-- | builtin-diff.c | 8 | ||||
| -rw-r--r-- | cache.h | 3 | ||||
| -rw-r--r-- | config.c | 5 | ||||
| -rw-r--r-- | environment.c | 3 | ||||
| -rw-r--r-- | preload-index.c | 91 |
9 files changed, 122 insertions, 10 deletions
diff --git a/Documentation/config.txt b/Documentation/config.txt index 32dcd643d2..0d96e763ac 100644 --- a/Documentation/config.txt +++ b/Documentation/config.txt @@ -413,6 +413,15 @@ data writes properly, but can be useful for filesystems that do not use journalling (traditional UNIX filesystems) or that only journal metadata and not file contents (OS X's HFS+, or Linux ext3 with "data=writeback"). +core.preloadindex:: + Enable parallel index preload for operations like 'git diff' ++ +This can speed up operations like 'git diff' and 'git status' especially +on filesystems like NFS that have weak caching semantics and thus +relatively high IO latencies. With this set to 'true', git will do the +index comparison to the filesystem data in parallel, allowing +overlapping IO's. + alias.*:: Command aliases for the linkgit:git[1] command wrapper - e.g. after defining "alias.last = cat-file commit HEAD", the invocation @@ -496,6 +496,7 @@ LIB_OBJS += write_or_die.o LIB_OBJS += ws.o LIB_OBJS += wt-status.o LIB_OBJS += xdiff-interface.o +LIB_OBJS += preload-index.o BUILTIN_OBJS += builtin-add.o BUILTIN_OBJS += builtin-annotate.o diff --git a/builtin-commit.c b/builtin-commit.c index 591d16b91e..1677e6b45f 100644 --- a/builtin-commit.c +++ b/builtin-commit.c @@ -225,18 +225,18 @@ static char *prepare_index(int argc, const char **argv, const char *prefix) if (interactive) { interactive_add(argc, argv, prefix); - if (read_cache() < 0) + if (read_cache_preload(NULL) < 0) die("index file corrupt"); commit_style = COMMIT_AS_IS; return get_index_file(); } - if (read_cache() < 0) - die("index file corrupt"); - if (*argv) pathspec = get_pathspec(prefix, argv); + if (read_cache_preload(pathspec) < 0) + die("index file corrupt"); + /* * Non partial, non as-is commit. * diff --git a/builtin-diff-files.c b/builtin-diff-files.c index 2b578c714d..5b64011de8 100644 --- a/builtin-diff-files.c +++ b/builtin-diff-files.c @@ -59,8 +59,8 @@ int cmd_diff_files(int argc, const char **argv, const char *prefix) (rev.diffopt.output_format & DIFF_FORMAT_PATCH)) rev.combine_merges = rev.dense_combined_merges = 1; - if (read_cache() < 0) { - perror("read_cache"); + if (read_cache_preload(rev.diffopt.paths) < 0) { + perror("read_cache_preload"); return -1; } result = run_diff_files(&rev, options); diff --git a/builtin-diff.c b/builtin-diff.c index 7ceceeb6ff..1447c1d6ba 100644 --- a/builtin-diff.c +++ b/builtin-diff.c @@ -134,8 +134,8 @@ static int builtin_diff_index(struct rev_info *revs, revs->max_count != -1 || revs->min_age != -1 || revs->max_age != -1) usage(builtin_diff_usage); - if (read_cache() < 0) { - perror("read_cache"); + if (read_cache_preload(revs->diffopt.paths) < 0) { + perror("read_cache_preload"); return -1; } return run_diff_index(revs, cached); @@ -234,8 +234,8 @@ static int builtin_diff_files(struct rev_info *revs, int argc, const char **argv revs->combine_merges = revs->dense_combined_merges = 1; setup_work_tree(); - if (read_cache() < 0) { - perror("read_cache"); + if (read_cache_preload(revs->diffopt.paths) < 0) { + perror("read_cache_preload"); return -1; } result = run_diff_files(revs, options); @@ -262,6 +262,7 @@ static inline void remove_name_hash(struct cache_entry *ce) #define read_cache() read_index(&the_index) #define read_cache_from(path) read_index_from(&the_index, (path)) +#define read_cache_preload(pathspec) read_index_preload(&the_index, (pathspec)) #define is_cache_unborn() is_index_unborn(&the_index) #define read_cache_unmerged() read_index_unmerged(&the_index) #define write_cache(newfd, cache, entries) write_index(&the_index, (newfd)) @@ -368,6 +369,7 @@ extern int init_db(const char *template_dir, unsigned int flags); /* Initialize and use the cache information */ extern int read_index(struct index_state *); +extern int read_index_preload(struct index_state *, const char **pathspec); extern int read_index_from(struct index_state *, const char *path); extern int is_index_unborn(struct index_state *); extern int read_index_unmerged(struct index_state *); @@ -458,6 +460,7 @@ extern size_t packed_git_limit; extern size_t delta_base_cache_limit; extern int auto_crlf; extern int fsync_object_files; +extern int core_preload_index; enum safe_crlf { SAFE_CRLF_FALSE = 0, @@ -490,6 +490,11 @@ static int git_default_core_config(const char *var, const char *value) return 0; } + if (!strcmp(var, "core.preloadindex")) { + core_preload_index = git_config_bool(var, value); + return 0; + } + /* Add other config variables here and to Documentation/config.txt. */ return 0; } diff --git a/environment.c b/environment.c index bb96ac0a71..e278bce0ea 100644 --- a/environment.c +++ b/environment.c @@ -43,6 +43,9 @@ unsigned whitespace_rule_cfg = WS_DEFAULT_RULE; enum branch_track git_branch_track = BRANCH_TRACK_REMOTE; enum rebase_setup_type autorebase = AUTOREBASE_NEVER; +/* Parallel index stat data preload? */ +int core_preload_index = 0; + /* This is set by setup_git_dir_gently() and/or git_default_config() */ char *git_work_tree_cfg; static char *work_tree; diff --git a/preload-index.c b/preload-index.c new file mode 100644 index 0000000000..6253578c96 --- /dev/null +++ b/preload-index.c @@ -0,0 +1,91 @@ +/* + * Copyright (C) 2008 Linus Torvalds + */ +#include "cache.h" +#include <pthread.h> + +/* + * Mostly randomly chosen maximum thread counts: we + * cap the parallelism to 20 threads, and we want + * to have at least 500 lstat's per thread for it to + * be worth starting a thread. + */ +#define MAX_PARALLEL (20) +#define THREAD_COST (500) + +struct thread_data { + pthread_t pthread; + struct index_state *index; + const char **pathspec; + int offset, nr; +}; + +static void *preload_thread(void *_data) +{ + int nr; + struct thread_data *p = _data; + struct index_state *index = p->index; + struct cache_entry **cep = index->cache + p->offset; + + nr = p->nr; + if (nr + p->offset > index->cache_nr) + nr = index->cache_nr - p->offset; + + do { + struct cache_entry *ce = *cep++; + struct stat st; + + if (ce_stage(ce)) + continue; + if (ce_uptodate(ce)) + continue; + if (!ce_path_match(ce, p->pathspec)) + continue; + if (lstat(ce->name, &st)) + continue; + if (ie_match_stat(index, ce, &st, 0)) + continue; + ce_mark_uptodate(ce); + } while (--nr > 0); + return NULL; +} + +static void preload_index(struct index_state *index, const char **pathspec) +{ + int threads, i, work, offset; + struct thread_data data[MAX_PARALLEL]; + + if (!core_preload_index) + return; + + threads = index->cache_nr / THREAD_COST; + if (threads < 2) + return; + if (threads > MAX_PARALLEL) + threads = MAX_PARALLEL; + offset = 0; + work = (index->cache_nr + threads - 1) / threads; + for (i = 0; i < threads; i++) { + struct thread_data *p = data+i; + p->index = index; + p->pathspec = pathspec; + p->offset = offset; + p->nr = work; + offset += work; + if (pthread_create(&p->pthread, NULL, preload_thread, p)) + die("unable to create threaded lstat"); + } + for (i = 0; i < threads; i++) { + struct thread_data *p = data+i; + if (pthread_join(p->pthread, NULL)) + die("unable to join threaded lstat"); + } +} + +int read_index_preload(struct index_state *index, const char **pathspec) +{ + int retval = read_index(index); + + preload_index(index, pathspec); + return retval; +} |