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authorRyujiro Shibuya <ryujiro.shibuya@owmobility.com>2019-10-16 06:30:02 +0100
committerAndrew Yourtchenko <ayourtch@gmail.com>2019-10-29 09:49:06 +0000
commit87aadb1e758b4f853e7b75770297f33032364d68 (patch)
treef7a064abd7d607ca6c70640a102036bc2443bf83
parente68fe9c5163a74f39e400dc44c711677ddb01466 (diff)
svm: immediate fifo growth even when wrapped
Type: fix - when the fifo is wrapped, and if applicable, insert a new chunk after the tail-chunk and rebuild the rb_tree. - make sure that this new algorithm can be applied only when the fifo is used by a single thread (master-thread of the fifo). Signed-off-by: Ryujiro Shibuya <ryujiro.shibuya@owmobility.com> Change-Id: I3fc187bc496ea537ca24381e4abc08d2906c9e03 (cherry picked from commit 8e20fe7ab445e2de80caabb298aef8a658f6d4ab)
-rw-r--r--src/svm/svm_fifo.c116
-rw-r--r--src/svm/svm_fifo.h9
2 files changed, 117 insertions, 8 deletions
diff --git a/src/svm/svm_fifo.c b/src/svm/svm_fifo.c
index 6bd6f9157bc..975a82026f7 100644
--- a/src/svm/svm_fifo.c
+++ b/src/svm/svm_fifo.c
@@ -590,6 +590,95 @@ svm_fifo_add_chunk (svm_fifo_t * f, svm_fifo_chunk_t * c)
f->flags |= SVM_FIFO_F_MULTI_CHUNK;
}
+ /* If fifo is not wrapped, update the size now */
+ if (!svm_fifo_is_wrapped (f))
+ {
+ /* Initialize chunks and add to lookup rbtree */
+ cur = c;
+ if (f->new_chunks)
+ {
+ prev = f->new_chunks;
+ while (prev->next)
+ prev = prev->next;
+ prev->next = c;
+ }
+ else
+ prev = f->end_chunk;
+
+ while (cur)
+ {
+ cur->start_byte = prev->start_byte + prev->length;
+ rb_tree_add2 (&f->chunk_lookup, cur->start_byte,
+ pointer_to_uword (cur));
+ prev = cur;
+ cur = cur->next;
+ }
+
+ ASSERT (!f->new_chunks);
+ svm_fifo_grow (f, c);
+ return;
+ }
+
+ /* Wrapped */
+ if (f->flags & SVM_FIFO_F_SINGLE_THREAD_OWNED)
+ {
+ ASSERT (f->master_thread_index == os_get_thread_index ());
+
+ if (!f->new_chunks && f->head_chunk != f->tail_chunk)
+ {
+ u32 head = 0, tail = 0;
+ f_load_head_tail_cons (f, &head, &tail);
+
+ svm_fifo_chunk_t *tmp = f->tail_chunk->next;
+
+ prev = f->tail_chunk;
+ u32 add_bytes = 0;
+ cur = prev->next;
+ while (cur != f->start_chunk)
+ {
+ /* remove any existing rb_tree entry */
+ rb_tree_del (&f->chunk_lookup, cur->start_byte);
+ cur = cur->next;
+ }
+
+ /* insert new chunk after the tail_chunk */
+ f->tail_chunk->next = c;
+ while (c)
+ {
+ add_bytes += c->length;
+ c->start_byte = prev->start_byte + prev->length;
+ rb_tree_add2 (&f->chunk_lookup, c->start_byte,
+ pointer_to_uword (c));
+
+ prev = c;
+ c = c->next;
+ }
+ prev->next = tmp;
+
+ /* shift existing chunks along */
+ cur = tmp;
+ while (cur != f->start_chunk)
+ {
+ cur->start_byte = prev->start_byte + prev->length;
+ rb_tree_add2 (&f->chunk_lookup, cur->start_byte,
+ pointer_to_uword (cur));
+ prev = cur;
+ cur = cur->next;
+ }
+
+ f->size += add_bytes;
+ f->nitems = f->size - 1;
+ f->new_chunks = 0;
+ head += add_bytes;
+
+ clib_atomic_store_rel_n (&f->head, head);
+ ASSERT (svm_fifo_is_sane (f));
+
+ return;
+ }
+ }
+
+ /* Wrapped, and optimization of single-thread-owned fifo cannot be applied */
/* Initialize chunks and add to lookup rbtree */
cur = c;
if (f->new_chunks)
@@ -611,14 +700,6 @@ svm_fifo_add_chunk (svm_fifo_t * f, svm_fifo_chunk_t * c)
cur = cur->next;
}
- /* If fifo is not wrapped, update the size now */
- if (!svm_fifo_is_wrapped (f))
- {
- ASSERT (!f->new_chunks);
- svm_fifo_grow (f, c);
- return;
- }
-
/* Postpone size update */
if (!f->new_chunks)
{
@@ -1152,6 +1233,25 @@ svm_fifo_is_sane (svm_fifo_t * f)
return 1;
}
+u8
+svm_fifo_set_single_thread_owned (svm_fifo_t * f)
+{
+ if (f->flags & SVM_FIFO_F_SINGLE_THREAD_OWNED)
+ {
+ if (f->master_thread_index == os_get_thread_index ())
+ {
+ /* just a duplicate call */
+ return 0;
+ }
+
+ /* already owned by another thread */
+ return 1;
+ }
+
+ f->flags |= SVM_FIFO_F_SINGLE_THREAD_OWNED;
+ return 0;
+}
+
u8 *
format_ooo_segment (u8 * s, va_list * args)
{
diff --git a/src/svm/svm_fifo.h b/src/svm/svm_fifo.h
index 64ed53bf827..ce4c53d9abe 100644
--- a/src/svm/svm_fifo.h
+++ b/src/svm/svm_fifo.h
@@ -70,6 +70,7 @@ typedef enum svm_fifo_flag_
SVM_FIFO_F_SHRINK = 1 << 2,
SVM_FIFO_F_COLLECT_CHUNKS = 1 << 3,
SVM_FIFO_F_LL_TRACKED = 1 << 4,
+ SVM_FIFO_F_SINGLE_THREAD_OWNED = 1 << 5,
} svm_fifo_flag_t;
typedef struct _svm_fifo
@@ -477,6 +478,14 @@ ooo_segment_t *svm_fifo_first_ooo_segment (svm_fifo_t * f);
* @return 1 if sane, 0 otherwise
*/
u8 svm_fifo_is_sane (svm_fifo_t * f);
+/**
+ * Declare this fifo is used by only a single thread.
+ * In this special case, fifo-growth can be done in an efficient way without delay.
+ *
+ * @param f fifo
+ * @return 1 if the fifo is already owned by another thread, 0 otherwise
+ */
+u8 svm_fifo_set_single_thread_owned (svm_fifo_t * f);
format_function_t format_svm_fifo;
/**