This patch adds a new functions classifier_defer() and
classifier_publish(), which control when the classifier modifications
are made available to lookups. By default, all modifications are made
available to lookups immediately. Modifications made after a
classifier_defer() call MAY be 'deferred' for later 'publication'. A
call to classifier_publish() will both publish any deferred
modifications, and cause subsequent changes to to be published
immediately.
Currently any deferring is limited to the visibility of the subtable
vector changes. pvector now processes modifications mostly in a
working copy, which needs to be explicitly published with
pvector_publish(). pvector_publish() sorts the working copy and
removes gaps before publishing it.
This change helps avoiding O(n**2) memory behavior in corner cases,
where large number of rules with different masks are inserted or
deleted.
VMware-BZ: #1322017
Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Acked-by: Ben Pfaff <blp@nicira.com>
OpenFlow has priorities in the 16-bit unsigned range, from 0 to 65535.
In the classifier, it is sometimes useful to be able to have values below
and above this range. With the 'unsigned int' type used for priorities
until now, there were no values below the range, so some code worked
around it by converting priorities to 64-bit signed integers. This didn't
seem so great to me given that a plain 'int' also had the needed range.
This commit therefore changes the type used for priorities to int.
The interesting parts of this change are in pvector.h and classifier.c,
where one can see the elimination of the use of int64_t.
Signed-off-by: Ben Pfaff <blp@nicira.com>
Acked-by: Jarno Rajahalme <jrajahalme@nicira.com>
Factor out the priority vector code from the classifier.
Making the classifier use RCU instead of locking requires parallel
access to the priority vector, pointing to subtables in descending
priority order. When a new subtable is added, a new copy of the
priority vector is allocated, while the current readers can keep on
using the old copy they started with. Adding and removing subtables
is usually less frequent than adding and removing rules, so this
should not have a visible performance implication. As an optimization
for the userspace datapath use, where all the subtables have the same
priority, new subtables can be added to the end of the vector without
reallocation and without disturbing readers.
cls_subtables_reset() is now removed, as it served its purpose in bug
hunting. Checks on the new pvector are now incorporated into
tests/test-classifier.c.
Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Acked-by: Ben Pfaff <blp@nicira.com>
