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forked from pool/util-linux
util-linux/fix-lib-internal-cache-size.patch
Jan Engelhardt 4b94d5ddf0 Accepting request 1085768 from home:dgarcia:branches:Base:System
- Call fdupes without -s to avoid broken symlinks, pointing to
  different subpackage. boo#1209990
- Add upstream patch fix-lib-internal-cache-size.patch
  bsc#1210164, gh#util-linux/util-linux@2fa4168c8bc9

OBS-URL: https://build.opensuse.org/request/show/1085768
OBS-URL: https://build.opensuse.org/package/show/Base:System/util-linux?expand=0&rev=510
2023-05-09 18:33:25 +00:00

84 lines
2.5 KiB
Diff

From 2fa4168c8bc9d5438bc1dfadda293c7c21b6fa59 Mon Sep 17 00:00:00 2001
From: Michael Trapp <michael.trapp@sap.com>
Date: Mon, 6 Mar 2023 10:40:20 +0000
Subject: [PATCH] libuuid: fix lib internal cache size
The lib internal cache improves throughput in high load
scenarios but for applications with a low request rate,
the cache size must be adapted to this situation.
Therefore the cache size should be changed to the current
requirements of the application during runtime.
---
libuuid/src/gen_uuid.c | 30 ++++++++++++++++++++++--------
1 file changed, 22 insertions(+), 8 deletions(-)
Index: util-linux-2.38.1/libuuid/src/gen_uuid.c
===================================================================
--- util-linux-2.38.1.orig/libuuid/src/gen_uuid.c
+++ util-linux-2.38.1/libuuid/src/gen_uuid.c
@@ -442,25 +442,35 @@ int __uuid_generate_time(uuid_t out, int
*/
static int uuid_generate_time_generic(uuid_t out) {
#ifdef HAVE_TLS
+ /* thread local cache for uuidd based requests */
+ const int cs_min = (1<<6);
+ const int cs_max = (1<<18);
+ const int cs_factor = 2;
THREAD_LOCAL int num = 0;
- THREAD_LOCAL int cache_size = 1;
+ THREAD_LOCAL int cache_size = cs_min;
+ THREAD_LOCAL int last_used = 0;
THREAD_LOCAL struct uuid uu;
THREAD_LOCAL time_t last_time = 0;
time_t now;
- if (num > 0) {
+ if (num > 0) { /* expire cache */
now = time(NULL);
- if (now > last_time+1)
+ if (now > last_time+1) {
+ last_used = cache_size - num;
num = 0;
+ }
}
- if (num <= 0) {
+ if (num <= 0) { /* fill cache */
/*
* num + OP_BULK provides a local cache in each application.
* Start with a small cache size to cover short running applications
- * and increment the cache size over the runntime.
+ * and adjust the cache size over the runntime.
*/
- if (cache_size < 1000000)
- cache_size *= 10;
+ if ((last_used == cache_size) && (cache_size < cs_max))
+ cache_size *= cs_factor;
+ else if ((last_used < (cache_size / cs_factor)) && (cache_size > cs_min))
+ cache_size /= cs_factor;
+
num = cache_size;
if (get_uuid_via_daemon(UUIDD_OP_BULK_TIME_UUID,
@@ -470,9 +480,11 @@ static int uuid_generate_time_generic(uu
num--;
return 0;
}
+ /* request to daemon failed, reset cache */
num = 0;
+ cache_size = cs_min;
}
- if (num > 0) {
+ if (num > 0) { /* serve uuid from cache */
uu.time_low++;
if (uu.time_low == 0) {
uu.time_mid++;
@@ -481,6 +493,8 @@ static int uuid_generate_time_generic(uu
}
num--;
uuid_pack(&uu, out);
+ if (num == 0)
+ last_used = cache_size;
return 0;
}
#else