diff options
| -rw-r--r-- | Documentation/git-index-pack.txt | 10 | ||||
| -rw-r--r-- | Makefile | 2 | ||||
| -rw-r--r-- | builtin/index-pack.c | 341 | ||||
| -rw-r--r-- | compat/win32/pthread.h | 5 | ||||
| -rwxr-xr-x | t/perf/p5302-pack-index.sh | 40 |
5 files changed, 331 insertions, 67 deletions
diff --git a/Documentation/git-index-pack.txt b/Documentation/git-index-pack.txt index 909687fed4..39e6d0ddd8 100644 --- a/Documentation/git-index-pack.txt +++ b/Documentation/git-index-pack.txt @@ -74,6 +74,16 @@ OPTIONS --strict:: Die, if the pack contains broken objects or links. +--threads=<n>:: + Specifies the number of threads to spawn when resolving + deltas. This requires that index-pack be compiled with + pthreads otherwise this option is ignored with a warning. + This is meant to reduce packing time on multiprocessor + machines. The required amount of memory for the delta search + window is however multiplied by the number of threads. + Specifying 0 will cause git to auto-detect the number of CPU's + and use maximum 3 threads. + Note ---- @@ -2226,7 +2226,7 @@ builtin/branch.o builtin/checkout.o builtin/clone.o builtin/reset.o branch.o tra builtin/bundle.o bundle.o transport.o: bundle.h builtin/bisect--helper.o builtin/rev-list.o bisect.o: bisect.h builtin/clone.o builtin/fetch-pack.o transport.o: fetch-pack.h -builtin/grep.o builtin/pack-objects.o transport-helper.o thread-utils.o: thread-utils.h +builtin/index-pack.o builtin/grep.o builtin/pack-objects.o transport-helper.o thread-utils.o: thread-utils.h builtin/send-pack.o transport.o: send-pack.h builtin/log.o builtin/shortlog.o: shortlog.h builtin/prune.o builtin/reflog.o reachable.o: reachable.h diff --git a/builtin/index-pack.c b/builtin/index-pack.c index 83555e5635..dc2cfe6e6f 100644 --- a/builtin/index-pack.c +++ b/builtin/index-pack.c @@ -9,6 +9,7 @@ #include "progress.h" #include "fsck.h" #include "exec_cmd.h" +#include "thread-utils.h" static const char index_pack_usage[] = "git index-pack [-v] [-o <index-file>] [--keep | --keep=<msg>] [--verify] [--strict] (<pack-file> | --stdin [--fix-thin] [<pack-file>])"; @@ -38,6 +39,19 @@ struct base_data { int ofs_first, ofs_last; }; +#if !defined(NO_PTHREADS) && defined(NO_PREAD) +/* NO_PREAD uses compat/pread.c, which is not thread-safe. Disable threading. */ +#define NO_PTHREADS +#endif + +struct thread_local { +#ifndef NO_PTHREADS + pthread_t thread; +#endif + struct base_data *base_cache; + size_t base_cache_used; +}; + /* * Even if sizeof(union delta_base) == 24 on 64-bit archs, we really want * to memcmp() only the first 20 bytes. @@ -54,11 +68,11 @@ struct delta_entry { static struct object_entry *objects; static struct delta_entry *deltas; -static struct base_data *base_cache; -static size_t base_cache_used; +static struct thread_local nothread_data; static int nr_objects; static int nr_deltas; static int nr_resolved_deltas; +static int nr_threads; static int from_stdin; static int strict; @@ -75,6 +89,77 @@ static git_SHA_CTX input_ctx; static uint32_t input_crc32; static int input_fd, output_fd, pack_fd; +#ifndef NO_PTHREADS + +static struct thread_local *thread_data; +static int nr_dispatched; +static int threads_active; + +static pthread_mutex_t read_mutex; +#define read_lock() lock_mutex(&read_mutex) +#define read_unlock() unlock_mutex(&read_mutex) + +static pthread_mutex_t counter_mutex; +#define counter_lock() lock_mutex(&counter_mutex) +#define counter_unlock() unlock_mutex(&counter_mutex) + +static pthread_mutex_t work_mutex; +#define work_lock() lock_mutex(&work_mutex) +#define work_unlock() unlock_mutex(&work_mutex) + +static pthread_key_t key; + +static inline void lock_mutex(pthread_mutex_t *mutex) +{ + if (threads_active) + pthread_mutex_lock(mutex); +} + +static inline void unlock_mutex(pthread_mutex_t *mutex) +{ + if (threads_active) + pthread_mutex_unlock(mutex); +} + +/* + * Mutex and conditional variable can't be statically-initialized on Windows. + */ +static void init_thread(void) +{ + init_recursive_mutex(&read_mutex); + pthread_mutex_init(&counter_mutex, NULL); + pthread_mutex_init(&work_mutex, NULL); + pthread_key_create(&key, NULL); + thread_data = xcalloc(nr_threads, sizeof(*thread_data)); + threads_active = 1; +} + +static void cleanup_thread(void) +{ + if (!threads_active) + return; + threads_active = 0; + pthread_mutex_destroy(&read_mutex); + pthread_mutex_destroy(&counter_mutex); + pthread_mutex_destroy(&work_mutex); + pthread_key_delete(key); + free(thread_data); +} + +#else + +#define read_lock() +#define read_unlock() + +#define counter_lock() +#define counter_unlock() + +#define work_lock() +#define work_unlock() + +#endif + + static int mark_link(struct object *obj, int type, void *data) { if (!obj) @@ -226,6 +311,25 @@ static NORETURN void bad_object(unsigned long offset, const char *format, ...) die(_("pack has bad object at offset %lu: %s"), offset, buf); } +static inline struct thread_local *get_thread_data(void) +{ +#ifndef NO_PTHREADS + if (threads_active) + return pthread_getspecific(key); + assert(!threads_active && + "This should only be reached when all threads are gone"); +#endif + return ¬hread_data; +} + +#ifndef NO_PTHREADS +static void set_thread_data(struct thread_local *data) +{ + if (threads_active) + pthread_setspecific(key, data); +} +#endif + static struct base_data *alloc_base_data(void) { struct base_data *base = xmalloc(sizeof(struct base_data)); @@ -240,15 +344,16 @@ static void free_base_data(struct base_data *c) if (c->data) { free(c->data); c->data = NULL; - base_cache_used -= c->size; + get_thread_data()->base_cache_used -= c->size; } } static void prune_base_data(struct base_data *retain) { struct base_data *b; - for (b = base_cache; - base_cache_used > delta_base_cache_limit && b; + struct thread_local *data = get_thread_data(); + for (b = data->base_cache; + data->base_cache_used > delta_base_cache_limit && b; b = b->child) { if (b->data && b != retain) free_base_data(b); @@ -260,12 +365,12 @@ static void link_base_data(struct base_data *base, struct base_data *c) if (base) base->child = c; else - base_cache = c; + get_thread_data()->base_cache = c; c->base = base; c->child = NULL; if (c->data) - base_cache_used += c->size; + get_thread_data()->base_cache_used += c->size; prune_base_data(c); } @@ -275,7 +380,7 @@ static void unlink_base_data(struct base_data *c) if (base) base->child = NULL; else - base_cache = NULL; + get_thread_data()->base_cache = NULL; free_base_data(c); } @@ -467,19 +572,24 @@ static void sha1_object(const void *data, unsigned long size, enum object_type type, unsigned char *sha1) { hash_sha1_file(data, size, typename(type), sha1); + read_lock(); if (has_sha1_file(sha1)) { void *has_data; enum object_type has_type; unsigned long has_size; has_data = read_sha1_file(sha1, &has_type, &has_size); + read_unlock(); if (!has_data) die(_("cannot read existing object %s"), sha1_to_hex(sha1)); if (size != has_size || type != has_type || memcmp(data, has_data, size) != 0) die(_("SHA1 COLLISION FOUND WITH %s !"), sha1_to_hex(sha1)); free(has_data); - } + } else + read_unlock(); + if (strict) { + read_lock(); if (type == OBJ_BLOB) { struct blob *blob = lookup_blob(sha1); if (blob) @@ -513,6 +623,7 @@ static void sha1_object(const void *data, unsigned long size, } obj->flags |= FLAG_CHECKED; } + read_unlock(); } } @@ -558,7 +669,7 @@ static void *get_base_data(struct base_data *c) if (!delta_nr) { c->data = get_data_from_pack(obj); c->size = obj->size; - base_cache_used += c->size; + get_thread_data()->base_cache_used += c->size; prune_base_data(c); } for (; delta_nr > 0; delta_nr--) { @@ -574,7 +685,7 @@ static void *get_base_data(struct base_data *c) free(raw); if (!c->data) bad_object(obj->idx.offset, _("failed to apply delta")); - base_cache_used += c->size; + get_thread_data()->base_cache_used += c->size; prune_base_data(c); } free(delta); @@ -602,7 +713,9 @@ static void resolve_delta(struct object_entry *delta_obj, bad_object(delta_obj->idx.offset, _("failed to apply delta")); sha1_object(result->data, result->size, delta_obj->real_type, delta_obj->idx.sha1); + counter_lock(); nr_resolved_deltas++; + counter_unlock(); } static struct base_data *find_unresolved_deltas_1(struct base_data *base, @@ -688,19 +801,50 @@ static int compare_delta_entry(const void *a, const void *b) objects[delta_b->obj_no].type); } -/* Parse all objects and return the pack content SHA1 hash */ +static void resolve_base(struct object_entry *obj) +{ + struct base_data *base_obj = alloc_base_data(); + base_obj->obj = obj; + base_obj->data = NULL; + find_unresolved_deltas(base_obj); +} + +#ifndef NO_PTHREADS +static void *threaded_second_pass(void *data) +{ + set_thread_data(data); + for (;;) { + int i; + work_lock(); + display_progress(progress, nr_resolved_deltas); + while (nr_dispatched < nr_objects && + is_delta_type(objects[nr_dispatched].type)) + nr_dispatched++; + if (nr_dispatched >= nr_objects) { + work_unlock(); + break; + } + i = nr_dispatched++; + work_unlock(); + + resolve_base(&objects[i]); + } + return NULL; +} +#endif + +/* + * First pass: + * - find locations of all objects; + * - calculate SHA1 of all non-delta objects; + * - remember base (SHA1 or offset) for all deltas. + */ static void parse_pack_objects(unsigned char *sha1) { int i; struct delta_entry *delta = deltas; struct stat st; - /* - * First pass: - * - find locations of all objects; - * - calculate SHA1 of all non-delta objects; - * - remember base (SHA1 or offset) for all deltas. - */ if (verbose) progress = start_progress( from_stdin ? _("Receiving objects") : _("Indexing objects"), @@ -734,6 +878,19 @@ static void parse_pack_objects(unsigned char *sha1) if (S_ISREG(st.st_mode) && lseek(input_fd, 0, SEEK_CUR) - input_len != st.st_size) die(_("pack has junk at the end")); +} + +/* + * Second pass: + * - for all non-delta objects, look if it is used as a base for + * deltas; + * - if used as a base, uncompress the object and apply all deltas, + * recursively checking if the resulting object is used as a base + * for some more deltas. + */ +static void resolve_deltas(void) +{ + int i; if (!nr_deltas) return; @@ -742,29 +899,83 @@ static void parse_pack_objects(unsigned char *sha1) qsort(deltas, nr_deltas, sizeof(struct delta_entry), compare_delta_entry); - /* - * Second pass: - * - for all non-delta objects, look if it is used as a base for - * deltas; - * - if used as a base, uncompress the object and apply all deltas, - * recursively checking if the resulting object is used as a base - * for some more deltas. - */ if (verbose) progress = start_progress(_("Resolving deltas"), nr_deltas); + +#ifndef NO_PTHREADS + nr_dispatched = 0; + if (nr_threads > 1 || getenv("GIT_FORCE_THREADS")) { + init_thread(); + for (i = 0; i < nr_threads; i++) { + int ret = pthread_create(&thread_data[i].thread, NULL, + threaded_second_pass, thread_data + i); + if (ret) + die("unable to create thread: %s", strerror(ret)); + } + for (i = 0; i < nr_threads; i++) + pthread_join(thread_data[i].thread, NULL); + cleanup_thread(); + return; + } +#endif + for (i = 0; i < nr_objects; i++) { struct object_entry *obj = &objects[i]; - struct base_data *base_obj = alloc_base_data(); if (is_delta_type(obj->type)) continue; - base_obj->obj = obj; - base_obj->data = NULL; - find_unresolved_deltas(base_obj); + resolve_base(obj); display_progress(progress, nr_resolved_deltas); } } +/* + * Third pass: + * - append objects to convert thin pack to full pack if required + * - write the final 20-byte SHA-1 + */ +static void fix_unresolved_deltas(struct sha1file *f, int nr_unresolved); +static void conclude_pack(int fix_thin_pack, const char *curr_pack, unsigned char *pack_sha1) +{ + if (nr_deltas == nr_resolved_deltas) { + stop_progress(&progress); + /* Flush remaining pack final 20-byte SHA1. */ + flush(); + return; + } + + if (fix_thin_pack) { + struct sha1file *f; + unsigned char read_sha1[20], tail_sha1[20]; + char msg[48]; + int nr_unresolved = nr_deltas - nr_resolved_deltas; + int nr_objects_initial = nr_objects; + if (nr_unresolved <= 0) + die(_("confusion beyond insanity")); + objects = xrealloc(objects, + (nr_objects + nr_unresolved + 1) + * sizeof(*objects)); + f = sha1fd(output_fd, curr_pack); + fix_unresolved_deltas(f, nr_unresolved); + sprintf(msg, "completed with %d local objects", + nr_objects - nr_objects_initial); + stop_progress_msg(&progress, msg); + sha1close(f, tail_sha1, 0); + hashcpy(read_sha1, pack_sha1); + fixup_pack_header_footer(output_fd, pack_sha1, + curr_pack, nr_objects, + read_sha1, consumed_bytes-20); + if (hashcmp(read_sha1, tail_sha1) != 0) + die("Unexpected tail checksum for %s " + "(disk corruption?)", curr_pack); + } + if (nr_deltas != nr_resolved_deltas) + die(Q_("pack has %d unresolved delta", + "pack has %d unresolved deltas", + nr_deltas - nr_resolved_deltas), + nr_deltas - nr_resolved_deltas); +} + static int write_compressed(struct sha1file *f, void *in, unsigned int size) { git_zstream stream; @@ -968,6 +1179,18 @@ static int git_index_pack_config(const char *k, const char *v, void *cb) die("bad pack.indexversion=%"PRIu32, opts->version); return 0; } + if (!strcmp(k, "pack.threads")) { + nr_threads = git_config_int(k, v); + if (nr_threads < 0) + die("invalid number of threads specified (%d)", + nr_threads); +#ifdef NO_PTHREADS + if (nr_threads != 1) + warning("no threads support, ignoring %s", k); + nr_threads = 1; +#endif + return 0; + } return git_default_config(k, v, cb); } @@ -1129,6 +1352,17 @@ int cmd_index_pack(int argc, const char **argv, const char *prefix) keep_msg = ""; } else if (!prefixcmp(arg, "--keep=")) { keep_msg = arg + 7; + } else if (!prefixcmp(arg, "--threads=")) { + char *end; + nr_threads = strtoul(arg+10, &end, 0); + if (!arg[10] || *end || nr_threads < 0) + usage(index_pack_usage); +#ifdef NO_PTHREADS + if (nr_threads != 1) + warning("no threads support, " + "ignoring %s", arg); + nr_threads = 1; +#endif } else if (!prefixcmp(arg, "--pack_header=")) { struct pack_header *hdr; char *c; @@ -1200,47 +1434,22 @@ int cmd_index_pack(int argc, const char **argv, const char *prefix) if (strict) opts.flags |= WRITE_IDX_STRICT; +#ifndef NO_PTHREADS + if (!nr_threads) { + nr_threads = online_cpus(); + /* An experiment showed that more threads does not mean faster */ + if (nr_threads > 3) + nr_threads = 3; + } +#endif + curr_pack = open_pack_file(pack_name); parse_pack_header(); objects = xcalloc(nr_objects + 1, sizeof(struct object_entry)); deltas = xcalloc(nr_objects, sizeof(struct delta_entry)); parse_pack_objects(pack_sha1); - if (nr_deltas == nr_resolved_deltas) { - stop_progress(&progress); - /* Flush remaining pack final 20-byte SHA1. */ - flush(); - } else { - if (fix_thin_pack) { - struct sha1file *f; - unsigned char read_sha1[20], tail_sha1[20]; - char msg[48]; - int nr_unresolved = nr_deltas - nr_resolved_deltas; - int nr_objects_initial = nr_objects; - if (nr_unresolved <= 0) - die(_("confusion beyond insanity")); - objects = xrealloc(objects, - (nr_objects + nr_unresolved + 1) - * sizeof(*objects)); - f = sha1fd(output_fd, curr_pack); - fix_unresolved_deltas(f, nr_unresolved); - sprintf(msg, "completed with %d local objects", - nr_objects - nr_objects_initial); - stop_progress_msg(&progress, msg); - sha1close(f, tail_sha1, 0); - hashcpy(read_sha1, pack_sha1); - fixup_pack_header_footer(output_fd, pack_sha1, - curr_pack, nr_objects, - read_sha1, consumed_bytes-20); - if (hashcmp(read_sha1, tail_sha1) != 0) - die("Unexpected tail checksum for %s " - "(disk corruption?)", curr_pack); - } - if (nr_deltas != nr_resolved_deltas) - die(Q_("pack has %d unresolved delta", - "pack has %d unresolved deltas", - nr_deltas - nr_resolved_deltas), - nr_deltas - nr_resolved_deltas); - } + resolve_deltas(); + conclude_pack(fix_thin_pack, curr_pack, pack_sha1); free(deltas); if (strict) check_objects(); diff --git a/compat/win32/pthread.h b/compat/win32/pthread.h index 2e20548557..8ad187344f 100644 --- a/compat/win32/pthread.h +++ b/compat/win32/pthread.h @@ -86,6 +86,11 @@ static inline int pthread_key_create(pthread_key_t *keyp, void (*destructor)(voi return (*keyp = TlsAlloc()) == TLS_OUT_OF_INDEXES ? EAGAIN : 0; } +static inline int pthread_key_delete(pthread_key_t key) +{ + return TlsFree(key) ? 0 : EINVAL; +} + static inline int pthread_setspecific(pthread_key_t key, const void *value) { return TlsSetValue(key, (void *)value) ? 0 : EINVAL; diff --git a/t/perf/p5302-pack-index.sh b/t/perf/p5302-pack-index.sh new file mode 100755 index 0000000000..6cb5b0d55b --- /dev/null +++ b/t/perf/p5302-pack-index.sh @@ -0,0 +1,40 @@ +#!/bin/sh + +test_description="Tests index-pack performance" + +. ./perf-lib.sh + +test_perf_large_repo + +test_expect_success 'repack' ' + git repack -ad && + PACK=`ls .git/objects/pack/*.pack | head -n1` && + test -f "$PACK" && + export PACK +' + +test_perf 'index-pack 0 threads' ' + GIT_DIR=t1 git index-pack --threads=1 --stdin < $PACK +' + +test_perf 'index-pack 1 thread ' ' + GIT_DIR=t2 GIT_FORCE_THREADS=1 git index-pack --threads=1 --stdin < $PACK +' + +test_perf 'index-pack 2 threads' ' + GIT_DIR=t3 git index-pack --threads=2 --stdin < $PACK +' + +test_perf 'index-pack 4 threads' ' + GIT_DIR=t4 git index-pack --threads=4 --stdin < $PACK +' + +test_perf 'index-pack 8 threads' ' + GIT_DIR=t5 git index-pack --threads=8 --stdin < $PACK +' + +test_perf 'index-pack default number of threads' ' + GIT_DIR=t6 git index-pack --stdin < $PACK +' + +test_done |