You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
78 lines
3.1 KiB
78 lines
3.1 KiB
2 years ago
|
From 8da81d2aba2768ced497790cc05b9f73c6268833 Mon Sep 17 00:00:00 2001
|
||
|
|
From: =?UTF-8?q?Zbigniew=20J=C4=99drzejewski-Szmek?= <zbyszek@in.waw.pl>
|
||
|
|
Date: Tue, 22 Jan 2019 17:30:48 +0100
|
||
|
|
Subject: [PATCH] journald: periodically drop cache for all dead PIDs
|
||
|
|
|
||
|
|
In normal use, this allow us to drop dead entries from the cache and reduces
|
||
|
|
the cache size so that we don't evict entries unnecessarily. The time limit is
|
||
|
|
there mostly to serve as a guard against malicious logging from many different
|
||
|
|
PIDs.
|
||
|
|
|
||
|
|
(cherry-picked from commit 91714a7f427a6c9c5c3be8b3819fee45050028f3)
|
||
|
|
|
||
|
|
Related: #1664976
|
||
|
|
---
|
||
|
|
src/journal/journald-context.c | 28 ++++++++++++++++++++++++++--
|
||
|
|
src/journal/journald-server.h | 2 ++
|
||
|
|
2 files changed, 28 insertions(+), 2 deletions(-)
|
||
|
|
|
||
|
|
diff --git a/src/journal/journald-context.c b/src/journal/journald-context.c
|
||
|
|
index 0f0dc1de4d..51f79fd803 100644
|
||
|
|
--- a/src/journal/journald-context.c
|
||
|
|
+++ b/src/journal/journald-context.c
|
||
|
|
@@ -541,15 +541,39 @@ refresh:
|
||
|
|
}
|
||
|
|
|
||
|
|
static void client_context_try_shrink_to(Server *s, size_t limit) {
|
||
|
|
+ ClientContext *c;
|
||
|
|
+ usec_t t;
|
||
|
|
+
|
||
|
|
assert(s);
|
||
|
|
|
||
|
|
+ /* Flush any cache entries for PIDs that have already moved on. Don't do this
|
||
|
|
+ * too often, since it's a slow process. */
|
||
|
|
+ t = now(CLOCK_MONOTONIC);
|
||
|
|
+ if (s->last_cache_pid_flush + MAX_USEC < t) {
|
||
|
|
+ unsigned n = prioq_size(s->client_contexts_lru), idx = 0;
|
||
|
|
+
|
||
|
|
+ /* We do a number of iterations based on the initial size of the prioq. When we remove an
|
||
|
|
+ * item, a new item is moved into its places, and items to the right might be reshuffled.
|
||
|
|
+ */
|
||
|
|
+ for (unsigned i = 0; i < n; i++) {
|
||
|
|
+ c = prioq_peek_by_index(s->client_contexts_lru, idx);
|
||
|
|
+
|
||
|
|
+ assert(c->n_ref == 0);
|
||
|
|
+
|
||
|
|
+ if (!pid_is_unwaited(c->pid))
|
||
|
|
+ client_context_free(s, c);
|
||
|
|
+ else
|
||
|
|
+ idx ++;
|
||
|
|
+ }
|
||
|
|
+
|
||
|
|
+ s->last_cache_pid_flush = t;
|
||
|
|
+ }
|
||
|
|
+
|
||
|
|
/* Bring the number of cache entries below the indicated limit, so that we can create a new entry without
|
||
|
|
* breaching the limit. Note that we only flush out entries that aren't pinned here. This means the number of
|
||
|
|
* cache entries may very well grow beyond the limit, if all entries stored remain pinned. */
|
||
|
|
|
||
|
|
while (hashmap_size(s->client_contexts) > limit) {
|
||
|
|
- ClientContext *c;
|
||
|
|
-
|
||
|
|
c = prioq_pop(s->client_contexts_lru);
|
||
|
|
if (!c)
|
||
|
|
break; /* All remaining entries are pinned, give up */
|
||
|
|
diff --git a/src/journal/journald-server.h b/src/journal/journald-server.h
|
||
|
|
index 983be8bb89..c6c9b1fb1d 100644
|
||
|
|
--- a/src/journal/journald-server.h
|
||
|
|
+++ b/src/journal/journald-server.h
|
||
|
|
@@ -163,6 +163,8 @@ struct Server {
|
||
|
|
Hashmap *client_contexts;
|
||
|
|
Prioq *client_contexts_lru;
|
||
|
|
|
||
|
|
+ usec_t last_cache_pid_flush;
|
||
|
|
+
|
||
|
|
ClientContext *my_context; /* the context of journald itself */
|
||
|
|
ClientContext *pid1_context; /* the context of PID 1 */
|
||
|
|
};
|