From debf70626878d1d4b03ac8d4a86ae64afb2272a9 Mon Sep 17 00:00:00 2001 From: Jeff King Date: Thu, 27 Oct 2016 06:24:19 -0400 Subject: sha1_file: stop opening files with O_NOATIME When we open object files, we try to do so with O_NOATIME. This dates back to 144bde78e9 (Use O_NOATIME when opening the sha1 files., 2005-04-23), which is an optimization to avoid creating a bunch of dirty inodes when we're accessing many objects. But a few things have changed since then: 1. In June 2005, git learned about packfiles, which means we would do a lot fewer atime updates (rather than one per object access, we'd generally get one per packfile). 2. In late 2006, Linux learned about "relatime", which is generally the default on modern installs. So performance around atimes updates is a non-issue there these days. All the world isn't Linux, but as it turns out, Linux is the only platform to implement O_NOATIME in the first place. So it's very unlikely that this code is helping anybody these days. It's not a particularly large amount of code, but the fallback-retry creates complexity. E.g., we do a similar fallback for CLOEXEC; which one should take precedence, or should we try all possible combinations? Dropping O_NOATIME makes those questions go away. Signed-off-by: Jeff King Signed-off-by: Junio C Hamano --- sha1_file.c | 15 +-------------- 1 file changed, 1 insertion(+), 14 deletions(-) diff --git a/sha1_file.c b/sha1_file.c index 09045df1dc..6f02a57d8b 100644 --- a/sha1_file.c +++ b/sha1_file.c @@ -27,14 +27,6 @@ #include "list.h" #include "mergesort.h" -#ifndef O_NOATIME -#if defined(__linux__) && (defined(__i386__) || defined(__PPC__)) -#define O_NOATIME 01000000 -#else -#define O_NOATIME 0 -#endif -#endif - #define SZ_FMT PRIuMAX static inline uintmax_t sz_fmt(size_t s) { return s; } @@ -1561,7 +1553,7 @@ int check_sha1_signature(const unsigned char *sha1, void *map, int git_open(const char *name) { - static int sha1_file_open_flag = O_NOATIME | O_CLOEXEC; + static int sha1_file_open_flag = O_CLOEXEC; for (;;) { int fd; @@ -1577,11 +1569,6 @@ int git_open(const char *name) continue; } - /* Might the failure be due to O_NOATIME? */ - if (errno != ENOENT && (sha1_file_open_flag & O_NOATIME)) { - sha1_file_open_flag &= ~O_NOATIME; - continue; - } return -1; } } -- cgit v1.2.1