Inserting or removing a sequence of flows with different wildcard patterns
causes temporary use of O(n**2) memory due to pvector modifications inside
the classifier. This commit fixes the problem in two easy cases. There
is at least one more difficult case inside ovs-vswitchd that this does not
fix.
VMware-BZ: #1322017
CC: Jarno Rajahalme <jrajaha...@nicira.com>
Signed-off-by: Ben Pfaff <b...@nicira.com>
---
tests/ovs-ofctl.at | 13 +++++++++++++
utilities/ovs-ofctl.c | 3 +++
2 files changed, 16 insertions(+)
diff --git a/tests/ovs-ofctl.at b/tests/ovs-ofctl.at
index 446d8f5..7290ef1 100644
--- a/tests/ovs-ofctl.at
+++ b/tests/ovs-ofctl.at
@@ -2650,6 +2650,19 @@ AT_CHECK([ovs-ofctl diff-flows flows.txt br0], [2], [dnl
OVS_VSWITCHD_STOP
AT_CLEANUP
+AT_SETUP([ovs-ofctl diff-flows - N**2 memory use])
+# A bug in prior versions made this use on the order of 50000**2 * 8
+# bytes (about 20 GB) of RAM on 64-bit machines. The fixed version
+# should use much less than 1 GB. We try to set a virtual memory
+# limit of 1 GB, to force a failure in the presence of the bug even on
+# a machine with a ridiculous amount of RAM (and to prevent swap
+# death). We don't bother to check for failure of the ulimit command
+# since it's really just a precaution.
+ulimit -v 1048576
+for i in `seq 1 50000`; do echo "reg0=$i/$i actions=drop"; done > flows
+AT_CHECK([ovs-ofctl diff-flows flows flows])
+AT_CLEANUP
+
AT_SETUP([ovs-ofctl -F and -O interaction])
AT_CHECK([ovs-ofctl -F oxm -O openflow10], [1], [],
[ovs-ofctl: None of the enabled OpenFlow versions (OpenFlow10) supports any
of the enabled flow formats (OXM). (Use -O to enable additional OpenFlow
versions or -F to enable additional flow formats.)
diff --git a/utilities/ovs-ofctl.c b/utilities/ovs-ofctl.c
index 211c276..3d1d589 100644
--- a/utilities/ovs-ofctl.c
+++ b/utilities/ovs-ofctl.c
@@ -50,6 +50,7 @@
#include "ofproto/ofproto.h"
#include "openflow/nicira-ext.h"
#include "openflow/openflow.h"
+#include "ovs-rcu.h"
#include "packets.h"
#include "pcap-file.h"
#include "poll-loop.h"
@@ -2349,6 +2350,7 @@ fte_free_all(struct classifier *cls)
CLS_FOR_EACH_SAFE (fte, rule, cls) {
classifier_remove(cls, &fte->rule);
fte_free(fte);
+ ovsrcu_quiesce();
}
classifier_destroy(cls);
}
@@ -2375,6 +2377,7 @@ fte_insert(struct classifier *cls, const struct match
*match,
cls_rule_destroy(&old->rule);
free(old);
}
+ ovsrcu_quiesce();
}
/* Reads the flows in 'filename' as flow table entries in 'cls' for the version
--
2.1.1
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