Hi, On Sat, 5 Aug 2006, Junio C Hamano wrote: > Immediately after a bulk checkout, most of the paths in the > working tree would have the same timestamp as the index file, > and this would force ce_match_stat() to take slow path for all > of them. When writing an index file out, if many of the paths > have very new (read: the same timestamp as the index file being > written out) timestamp, we are better off delaying the return > from the command, to make sure that later command to touch the > working tree files will leave newer timestamps than recorded in > the index, thereby avoiding to take the slow path. This makes "make test" dog slow. How about making this overrideable? (It is just a guess, but I _think_ that the sleeping is worse than having to check the files with the same time stamp again and again -- a "git status" will help that). "make test" without this patch: real 9m59.314s user 0m36.580s sys 0m39.290s "make test" with this patch: real 1m36.429s user 0m37.410s sys 0m40.460s -- 8< -- [PATCH] read-cache: optionally disable being cautious with racy caches By setting the environment variable GIT_RISK_RACY_CACHE or the config variable core.riskRacyCache, the sleeping (to avoid a racy cache) is disabled. This is also used for "make test", drastically reducing the needed time. Signed-off-by: Johannes Schindelin <Johannes.Schindelin@xxxxxx> --- Documentation/config.txt | 4 ++++ Documentation/git.txt | 5 +++++ cache.h | 1 + config.c | 4 ++++ environment.c | 1 + read-cache.c | 3 ++- t/test-lib.sh | 2 ++ 7 files changed, 19 insertions(+), 1 deletions(-) diff --git a/Documentation/config.txt b/Documentation/config.txt index d89916b..b61fd91 100644 --- a/Documentation/config.txt +++ b/Documentation/config.txt @@ -103,6 +103,10 @@ core.legacyheaders:: database directly (where the "http://"; and "rsync://" protocols count as direct access). +core.riskRacyCache:: + A boolean which allows to disable the 1-second sleeping to avoid + a racy cache. + alias.*:: Command aliases for the gitlink:git[1] command wrapper - e.g. after defining "alias.last = cat-file commit HEAD", the invocation diff --git a/Documentation/git.txt b/Documentation/git.txt index ba525d3..ff464e8 100644 --- a/Documentation/git.txt +++ b/Documentation/git.txt @@ -649,6 +649,11 @@ other stderr telling about alias expansion, built-in command execution and external command execution. +'GIT_RISK_RACY_CACHE':: + If this variable is set, gitlink:git-read-cache[1] will never + sleep to avoid a racy cache by making the timestamps of the index + file newer than the files referenced in the index. + Discussion[[Discussion]] ------------------------ include::README[] diff --git a/cache.h b/cache.h index 19fdef6..e8bbe6d 100644 --- a/cache.h +++ b/cache.h @@ -174,6 +174,7 @@ #define REFRESH_UNMERGED 0x0002 /* allow #define REFRESH_QUIET 0x0004 /* be quiet about it */ #define REFRESH_IGNORE_MISSING 0x0008 /* ignore non-existent */ extern int refresh_cache(unsigned int flags); +extern int risk_racy_cache; struct lock_file { struct lock_file *next; diff --git a/config.c b/config.c index c6e6f6a..4ab9329 100644 --- a/config.c +++ b/config.c @@ -291,6 +291,10 @@ int git_default_config(const char *var, return 0; } + if (!strcmp(var, "core.riskracycache")) { + risk_racy_cache = git_config_bool(var, value); + } + if (!strcmp(var, "user.name")) { strlcpy(git_default_name, value, sizeof(git_default_name)); return 0; diff --git a/environment.c b/environment.c index 1ce3411..a481fc4 100644 --- a/environment.c +++ b/environment.c @@ -24,6 +24,7 @@ const char *apply_default_whitespace = N int zlib_compression_level = Z_DEFAULT_COMPRESSION; int pager_in_use; int pager_use_color = 1; +int risk_racy_cache = 0; static int dyn_git_object_dir, dyn_git_index_file, dyn_git_graft_file; static char *git_dir, *git_object_dir, *git_index_file, *git_refs_dir, diff --git a/read-cache.c b/read-cache.c index d64b503..f20dac5 100644 --- a/read-cache.c +++ b/read-cache.c @@ -1021,7 +1021,8 @@ int write_cache(int newfd, struct cache_ * This assumes that nobody is touching the working tree while * we are updating the index. */ - if (20 < recent || entries <= recent * 4) { + if (!risk_racy_cache && !getenv("GIT_RISK_RACY_CACHE") && + (20 < recent || entries <= recent * 4)) { now = fstat(newfd, &st) ? 0 : st.st_mtime; while (now && !fstat(newfd, &st) && st.st_mtime <= now) { struct timespec rq, rm; diff --git a/t/test-lib.sh b/t/test-lib.sh index b6d119a..3b6882d 100755 --- a/t/test-lib.sh +++ b/t/test-lib.sh @@ -197,6 +197,8 @@ # t/ subdirectory and are run in trash s PATH=$(pwd)/..:$PATH GIT_EXEC_PATH=$(pwd)/.. export PATH GIT_EXEC_PATH +GIT_RISK_RACY_CACHE=1 +export GIT_RISK_RACY_CACHE # Similarly use ../compat/subprocess.py if our python does not # have subprocess.py on its own. -- 1.4.2.rc3.g6b27 - : send the line "unsubscribe git" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html