session/svm: apis for fifo shrinking
Change-Id: Ie519683bb90aae6fb95f2a09e251cded1890ed41
Signed-off-by: Florin Coras <fcoras@cisco.com>
diff --git a/src/plugins/unittest/svm_fifo_test.c b/src/plugins/unittest/svm_fifo_test.c
index 7d83b10..8067c6b 100644
--- a/src/plugins/unittest/svm_fifo_test.c
+++ b/src/plugins/unittest/svm_fifo_test.c
@@ -2021,6 +2021,74 @@
}
static int
+sfifo_test_fifo_segment_fifo_shrink (int verbose)
+{
+ fifo_segment_main_t *sm = &segment_main;
+ fifo_segment_create_args_t _a, *a = &_a;
+ int i, rv, chunk_size = 4096, n_chunks;
+ fifo_segment_t *fs;
+ svm_fifo_t *f;
+
+ clib_memset (a, 0, sizeof (*a));
+ a->segment_name = "fifo-test1";
+ a->segment_size = 256 << 10;
+
+ rv = fifo_segment_create (sm, a);
+
+ SFIFO_TEST (!rv, "svm_fifo_segment_create returned %d", rv);
+
+ /*
+ * Alloc and grow fifo
+ */
+ fs = fifo_segment_get_segment (sm, a->new_segment_indices[0]);
+ f = fifo_segment_alloc_fifo (fs, chunk_size, FIFO_SEGMENT_RX_FIFO);
+
+ SFIFO_TEST (f != 0, "svm_fifo_segment_alloc_fifo");
+
+ for (i = 0; i < 9; i++)
+ {
+ fifo_segment_grow_fifo (fs, f, chunk_size);
+ if (f->size != (i + 2) * chunk_size)
+ SFIFO_TEST (0, "fifo size should be %u is %u",
+ (i + 2) * chunk_size, f->size);
+ }
+
+ rv = svm_fifo_reduce_size (f, 3.5 * chunk_size, 1 /* is producer */ );
+ SFIFO_TEST (rv == 3 * chunk_size, "len expected %u is %u", 3 * chunk_size,
+ rv);
+
+ n_chunks = fifo_segment_num_free_chunks (fs, chunk_size);
+ SFIFO_TEST (n_chunks == 0, "free chunks should be %u is %u", 0, n_chunks);
+
+ fifo_segment_collect_fifo_chunks (fs, f);
+
+ n_chunks = fifo_segment_num_free_chunks (fs, chunk_size);
+ SFIFO_TEST (n_chunks == 3, "free chunks should be %u is %u", 3, n_chunks);
+
+ rv = svm_fifo_reduce_size (f, 7 * chunk_size - 1, 1 /* is producer */ );
+ SFIFO_TEST (rv == 6 * chunk_size, "len expected %u is %u", 6 * chunk_size,
+ rv);
+
+ fifo_segment_collect_fifo_chunks (fs, f);
+
+ n_chunks = fifo_segment_num_free_chunks (fs, chunk_size);
+ SFIFO_TEST (n_chunks == 9, "free chunks should be %u is %u", 9, n_chunks);
+ /*
+ * Free
+ */
+ fifo_segment_free_fifo (fs, f);
+ n_chunks = fifo_segment_num_free_chunks (fs, ~0);
+ SFIFO_TEST (n_chunks == 9, "free chunks should be %u is %u", 9, n_chunks);
+
+ /*
+ * Cleanup
+ */
+ fifo_segment_delete (sm, fs);
+ vec_free (a->new_segment_indices);
+ return 0;
+}
+
+static int
sfifo_test_fifo_segment_slave (int verbose)
{
fifo_segment_create_args_t _a, *a = &_a;
@@ -2219,6 +2287,11 @@
if ((rv = sfifo_test_fifo_segment_fifo_grow (verbose)))
return -1;
}
+ else if (unformat (input, "shrink fifo"))
+ {
+ if ((rv = sfifo_test_fifo_segment_fifo_shrink (verbose)))
+ return -1;
+ }
else if (unformat (input, "all"))
{
if ((rv = sfifo_test_fifo_segment_hello_world (verbose)))
@@ -2227,6 +2300,8 @@
return -1;
if ((rv = sfifo_test_fifo_segment_fifo_grow (verbose)))
return -1;
+ if ((rv = sfifo_test_fifo_segment_fifo_shrink (verbose)))
+ return -1;
/* Pretty slow so avoid running it always
if ((rv = sfifo_test_fifo_segment_master_slave (verbose)))
return -1;
diff --git a/src/svm/fifo_segment.c b/src/svm/fifo_segment.c
index 9c332d6..0263d1a 100644
--- a/src/svm/fifo_segment.c
+++ b/src/svm/fifo_segment.c
@@ -570,6 +570,35 @@
return 0;
}
+int
+fifo_segment_collect_fifo_chunks (fifo_segment_t * fs, svm_fifo_t * f)
+{
+ svm_fifo_chunk_t *cur, *next;
+ ssvm_shared_header_t *sh;
+ void *oldheap;
+ int fl_index;
+
+ sh = fs->ssvm.sh;
+ ssvm_lock_non_recursive (sh, 1);
+
+ oldheap = ssvm_push_heap (sh);
+ cur = svm_fifo_collect_chunks (f);
+
+ while (cur)
+ {
+ next = cur->next;
+ fl_index = fs_free_list_for_size (cur->length);
+ cur->next = fs->h->free_chunks[fl_index];
+ fs->h->free_chunks[fl_index] = cur;
+ cur = next;
+ }
+
+ ssvm_pop_heap (oldheap);
+ ssvm_unlock_non_recursive (sh);
+
+ return 0;
+}
+
/**
* Get number of active fifos
*/
diff --git a/src/svm/fifo_segment.h b/src/svm/fifo_segment.h
index 6ff538f..bb4f408 100644
--- a/src/svm/fifo_segment.h
+++ b/src/svm/fifo_segment.h
@@ -128,6 +128,15 @@
*/
int fifo_segment_grow_fifo (fifo_segment_t * fs, svm_fifo_t * f,
u32 chunk_size);
+
+/**
+ * Collect unused chunks for fifo
+ *
+ * @param fs fifo segment for fifo
+ * @param f fifo whose chunks are to be collected
+ * @return 0 on success, error otherwise
+ */
+int fifo_segment_collect_fifo_chunks (fifo_segment_t * fs, svm_fifo_t * f);
u8 fifo_segment_has_fifos (fifo_segment_t * fs);
svm_fifo_t *fifo_segment_get_fifo_list (fifo_segment_t * fs);
u32 fifo_segment_num_fifos (fifo_segment_t * fs);
diff --git a/src/svm/svm_fifo.c b/src/svm/svm_fifo.c
index e017b61..3824d99 100644
--- a/src/svm/svm_fifo.c
+++ b/src/svm/svm_fifo.c
@@ -677,7 +677,10 @@
svm_fifo_chunk_t *cur;
u32 actual_len = 0;
- if (len > f->nitems)
+ /* Abort if trying to reduce by more than fifo size or if
+ * fifo is undergoing resizing already */
+ if (len >= f->size || f->size > f->nitems + 1
+ || (f->flags & SVM_FIFO_F_SHRINK) || (f->flags & SVM_FIFO_F_GROW))
return 0;
/* last chunk that will not be removed */
diff --git a/src/vnet/session/segment_manager.c b/src/vnet/session/segment_manager.c
index 9a8af3b..6213cd5 100644
--- a/src/vnet/session/segment_manager.c
+++ b/src/vnet/session/segment_manager.c
@@ -682,6 +682,37 @@
return rv;
}
+int
+segment_manager_collect_fifo_chunks (segment_manager_t * sm, svm_fifo_t * f)
+{
+ fifo_segment_t *fs;
+ int rv;
+
+ fs = segment_manager_get_segment_w_lock (sm, f->segment_index);
+ rv = fifo_segment_collect_fifo_chunks (fs, f);
+ segment_manager_segment_reader_unlock (sm);
+
+ return rv;
+}
+
+int
+segment_manager_shrink_fifo (segment_manager_t * sm, svm_fifo_t * f, u32 size,
+ u8 is_producer)
+{
+ int rv;
+
+ rv = svm_fifo_reduce_size (f, size, is_producer);
+
+ /* Nothing to collect at this point */
+ if (!is_producer)
+ return rv;
+
+ if (f->flags & SVM_FIFO_F_COLLECT_CHUNKS)
+ segment_manager_collect_fifo_chunks (sm, f);
+
+ return rv;
+}
+
u32
segment_manager_evt_q_expected_size (u32 q_len)
{
diff --git a/src/vnet/session/segment_manager.h b/src/vnet/session/segment_manager.h
index cbf8e35..8358c50 100644
--- a/src/vnet/session/segment_manager.h
+++ b/src/vnet/session/segment_manager.h
@@ -125,6 +125,40 @@
*/
int segment_manager_grow_fifo (segment_manager_t * sm, svm_fifo_t * f,
u32 size);
+
+/**
+ * Request to shrink fifo owned by segment manager
+ *
+ * If this is not called by the producer, no attempt is made to reduce the
+ * size until the producer tries to enqueue more data. To collect the chunks
+ * that are to be removed call @ref segment_manager_collect_fifo_chunks
+ *
+ * Size reduction does not affect fifo chunk boundaries. Therefore chunks are
+ * not split and the amount of bytes to be removed can be equal to or less
+ * than what was requested.
+ *
+ * @param sm segment manager that owns the fifo
+ * @param f fifo to be shrunk
+ * @param size amount of bytes to remove from fifo
+ * @param is_producer flag that indicates is caller is the producer for the
+ * fifo.
+ * @return actual number of bytes to be removed
+ */
+int segment_manager_shrink_fifo (segment_manager_t * sm, svm_fifo_t * f,
+ u32 size, u8 is_producer);
+
+/**
+ * Collect fifo chunks that are no longer used
+ *
+ * This should not be called unless SVM_FIFO_F_COLLECT_CHUNKS is set for
+ * the fifo. The chunks are returned to the fifo segment freelist.
+ *
+ * @param sm segment manager that owns the fifo
+ * @param f fifo whose chunks are to be collected
+ * @return 0 on success, error otherwise
+ */
+int segment_manager_collect_fifo_chunks (segment_manager_t * sm,
+ svm_fifo_t * f);
u8 segment_manager_has_fifos (segment_manager_t * sm);
svm_msg_q_t *segment_manager_alloc_queue (fifo_segment_t * fs,