| From 97f0b8fdbebac3fd3398079d3db3cccb853eb0e7 Mon Sep 17 00:00:00 2001 |
| From: Richard Frankel <rofrankel@google.com> |
| Date: Fri, 2 Dec 2016 13:46:40 -0500 |
| Subject: [PATCH] Disable lockfile_create linear backoff. |
| |
| Linear backoff causes very unfair behavior, in which the longer a |
| process has been waiting, the less likely it is to grab a contested |
| lock. |
| |
| Remove the backoff and check once per second instead. |
| --- |
| lockfile.c | 8 +++++--- |
| 1 file changed, 5 insertions(+), 3 deletions(-) |
| |
| diff --git a/lockfile.c b/lockfile.c |
| index f571a67..e52f3e4 100644 |
| --- a/lockfile.c |
| +++ b/lockfile.c |
| @@ -177,7 +177,7 @@ int lockfile_create(const char *lockfile, int retries, int flags) |
| char sysname[256]; |
| char buf[8]; |
| char *p; |
| - int sleeptime = 0; |
| + int sleeptime = 1; |
| int statfailed = 0; |
| int fd; |
| int i, e, len; |
| @@ -253,8 +253,10 @@ int lockfile_create(const char *lockfile, int retries, int flags) |
| for (i = 0; i < tries && tries > 0; i++) { |
| |
| if (!dontsleep) { |
| - sleeptime += 5; |
| - if (sleeptime > 60) sleeptime = 60; |
| + // GFiber modification: Disable linear backoff, which causes very unfair |
| + // behavior. |
| + // sleeptime += 5; |
| + // if (sleeptime > 60) sleeptime = 60; |
| #ifdef LIB |
| sleep(sleeptime); |
| #else |
| -- |
| 2.8.0.rc3.226.g39d4020 |
| |
