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authorDave Barach <dave@barachs.net>2017-04-14 16:46:44 -0400
committerFlorin Coras <florin.coras@gmail.com>2017-04-18 17:02:41 +0000
commit1f75cfd73320476a8f821064391fe368dd4bf75b (patch)
treedb7b236512fd5fe299bf8598f73e38e82938f8a0 /src/svm/svm_fifo.c
parentfb5b2af2c0bf1ea38129d6e7cf669e2c1d14e220 (diff)
Fix fifo ooo bugs and improve testing
Change-Id: If3c01e318bcb740ca5b240c63f712e2167082a80 Signed-off-by: Dave Barach <dave@barachs.net> Signed-off-by: Florin Coras <fcoras@cisco.com>
Diffstat (limited to 'src/svm/svm_fifo.c')
-rw-r--r--src/svm/svm_fifo.c126
1 files changed, 91 insertions, 35 deletions
diff --git a/src/svm/svm_fifo.c b/src/svm/svm_fifo.c
index 097bab77c9c..bd968aeac4c 100644
--- a/src/svm/svm_fifo.c
+++ b/src/svm/svm_fifo.c
@@ -15,6 +15,36 @@
#include <svm/svm_fifo.h>
+#define offset_lt(_a, _b) ((i32)((_a)-(_b)) < 0)
+#define offset_leq(_a, _b) ((i32)((_a)-(_b)) <= 0)
+
+u8 *
+format_ooo_segment (u8 * s, va_list * args)
+{
+ ooo_segment_t *seg = va_arg (*args, ooo_segment_t *);
+
+ s = format (s, "pos %u, len %u, next %d, prev %d",
+ seg->start, seg->length, seg->next, seg->prev);
+ return s;
+}
+
+u8 *
+format_ooo_list (u8 * s, va_list * args)
+{
+ svm_fifo_t *f = va_arg (*args, svm_fifo_t *);
+ u32 ooo_segment_index = f->ooos_list_head;
+ ooo_segment_t *seg;
+
+ while (ooo_segment_index != OOO_SEGMENT_INVALID_INDEX)
+ {
+ seg = pool_elt_at_index (f->ooo_segments, ooo_segment_index);
+ s = format (s, "\n %U", format_ooo_segment, seg);
+
+ ooo_segment_index = seg->next;
+ }
+ return s;
+}
+
/** create an svm fifo, in the current heap. Fails vs blow up the process */
svm_fifo_t *
svm_fifo_create (u32 data_size_in_bytes)
@@ -47,7 +77,7 @@ ooo_segment_new (svm_fifo_t * f, u32 start, u32 length)
pool_get (f->ooo_segments, s);
- s->fifo_position = start;
+ s->start = start;
s->length = length;
s->prev = s->next = OOO_SEGMENT_INVALID_INDEX;
@@ -88,14 +118,13 @@ static void
ooo_segment_add (svm_fifo_t * f, u32 offset, u32 length)
{
ooo_segment_t *s, *new_s, *prev, *next, *it;
- u32 new_index, position, end_offset, s_sof, s_eof, s_index;
+ u32 new_index, end_offset, s_sof, s_eof, s_index;
- position = (f->tail + offset) % f->nitems;
end_offset = offset + length;
if (f->ooos_list_head == OOO_SEGMENT_INVALID_INDEX)
{
- s = ooo_segment_new (f, position, length);
+ s = ooo_segment_new (f, offset, length);
f->ooos_list_head = s - f->ooo_segments;
f->ooos_newest = f->ooos_list_head;
return;
@@ -104,26 +133,26 @@ ooo_segment_add (svm_fifo_t * f, u32 offset, u32 length)
/* Find first segment that starts after new segment */
s = pool_elt_at_index (f->ooo_segments, f->ooos_list_head);
while (s->next != OOO_SEGMENT_INVALID_INDEX
- && ooo_segment_offset (f, s) <= offset)
+ && offset_leq (ooo_segment_offset (f, s), offset))
s = pool_elt_at_index (f->ooo_segments, s->next);
s_index = s - f->ooo_segments;
s_sof = ooo_segment_offset (f, s);
s_eof = ooo_segment_end_offset (f, s);
+ prev = ooo_segment_get_prev (f, s);
/* No overlap, add before current segment */
- if (end_offset < s_sof)
+ if (offset_lt (end_offset, s_sof)
+ && (!prev || offset_lt (prev->start + prev->length, offset)))
{
- new_s = ooo_segment_new (f, position, length);
+ new_s = ooo_segment_new (f, offset, length);
new_index = new_s - f->ooo_segments;
/* Pool might've moved, get segment again */
s = pool_elt_at_index (f->ooo_segments, s_index);
-
if (s->prev != OOO_SEGMENT_INVALID_INDEX)
{
new_s->prev = s->prev;
-
prev = pool_elt_at_index (f->ooo_segments, new_s->prev);
prev->next = new_index;
}
@@ -139,9 +168,9 @@ ooo_segment_add (svm_fifo_t * f, u32 offset, u32 length)
return;
}
/* No overlap, add after current segment */
- else if (s_eof < offset)
+ else if (offset_lt (s_eof, offset))
{
- new_s = ooo_segment_new (f, position, length);
+ new_s = ooo_segment_new (f, offset, length);
new_index = new_s - f->ooo_segments;
/* Pool might've moved, get segment again */
@@ -150,7 +179,6 @@ ooo_segment_add (svm_fifo_t * f, u32 offset, u32 length)
if (s->next != OOO_SEGMENT_INVALID_INDEX)
{
new_s->next = s->next;
-
next = pool_elt_at_index (f->ooo_segments, new_s->next);
next->prev = new_index;
}
@@ -167,7 +195,7 @@ ooo_segment_add (svm_fifo_t * f, u32 offset, u32 length)
*/
/* Merge at head */
- if (offset <= s_sof)
+ if (offset_leq (offset, s_sof))
{
/* If we have a previous, check if we overlap */
if (s->prev != OOO_SEGMENT_INVALID_INDEX)
@@ -176,26 +204,31 @@ ooo_segment_add (svm_fifo_t * f, u32 offset, u32 length)
/* New segment merges prev and current. Remove previous and
* update position of current. */
- if (ooo_segment_end_offset (f, prev) >= offset)
+ if (offset_leq (offset, ooo_segment_end_offset (f, prev)))
{
- s->fifo_position = prev->fifo_position;
+ s->start = prev->start;
s->length = s_eof - ooo_segment_offset (f, prev);
ooo_segment_del (f, s->prev);
}
+ else
+ {
+ s->start = offset;
+ s->length = s_eof - ooo_segment_offset (f, s);
+ }
}
else
{
- s->fifo_position = position;
+ s->start = offset;
s->length = s_eof - ooo_segment_offset (f, s);
}
/* The new segment's tail may cover multiple smaller ones */
- if (s_eof < end_offset)
+ if (offset_lt (s_eof, end_offset))
{
/* Remove segments completely covered */
it = (s->next != OOO_SEGMENT_INVALID_INDEX) ?
pool_elt_at_index (f->ooo_segments, s->next) : 0;
- while (it && ooo_segment_end_offset (f, it) < end_offset)
+ while (it && offset_lt (ooo_segment_end_offset (f, it), end_offset))
{
next = (it->next != OOO_SEGMENT_INVALID_INDEX) ?
pool_elt_at_index (f->ooo_segments, it->next) : 0;
@@ -207,7 +240,7 @@ ooo_segment_add (svm_fifo_t * f, u32 offset, u32 length)
s->length = end_offset - ooo_segment_offset (f, s);
/* If partial overlap with last, merge */
- if (it && ooo_segment_offset (f, it) < end_offset)
+ if (it && offset_lt (ooo_segment_offset (f, it), end_offset))
{
s->length +=
it->length - (ooo_segment_offset (f, it) - end_offset);
@@ -216,7 +249,7 @@ ooo_segment_add (svm_fifo_t * f, u32 offset, u32 length)
}
}
/* Last but overlapping previous */
- else if (s_eof <= end_offset)
+ else if (offset_leq (s_eof, end_offset))
{
s->length = end_offset - ooo_segment_offset (f, s);
}
@@ -247,7 +280,7 @@ ooo_segment_try_collect (svm_fifo_t * f, u32 n_bytes_enqueued)
s = pool_elt_at_index (f->ooo_segments, f->ooos_list_head);
/* If last tail update overlaps one/multiple ooo segments, remove them */
- diff = (f->nitems + f->tail - s->fifo_position) % f->nitems;
+ diff = (f->nitems + ((int) s->start - f->tail)) % f->nitems;
while (0 < diff && diff < n_bytes_enqueued)
{
/* Segment end is beyond the tail. Advance tail and be done */
@@ -262,7 +295,7 @@ ooo_segment_try_collect (svm_fifo_t * f, u32 n_bytes_enqueued)
{
index = s - f->ooo_segments;
s = pool_elt_at_index (f->ooo_segments, s->next);
- diff = (f->nitems + f->tail - s->fifo_position) % f->nitems;
+ diff = (f->nitems + ((int) s->start - f->tail)) % f->nitems;
ooo_segment_del (f, index);
}
/* End of search */
@@ -368,9 +401,20 @@ svm_fifo_enqueue_with_offset_internal (svm_fifo_t * f,
{
u32 total_copy_bytes, first_copy_bytes, second_copy_bytes;
u32 cursize, nitems;
- u32 tail_plus_offset;
+ u32 normalized_offset;
+ int rv;
- ASSERT (offset > 0);
+ /* Safety: don't wrap more than nitems/2 */
+ ASSERT ((f->nitems + offset - f->tail) % f->nitems < f->nitems / 2);
+
+ /* Users would do do well to avoid this */
+ if (PREDICT_FALSE (f->tail == (offset % f->nitems)))
+ {
+ rv = svm_fifo_enqueue_internal (f, pid, required_bytes, copy_from_here);
+ if (rv > 0)
+ return 0;
+ return -1;
+ }
/* read cursize, which can only increase while we're working */
cursize = svm_fifo_max_dequeue (f);
@@ -384,24 +428,24 @@ svm_fifo_enqueue_with_offset_internal (svm_fifo_t * f,
/* Number of bytes we're going to copy */
total_copy_bytes = required_bytes;
- tail_plus_offset = (f->tail + offset) % nitems;
+ normalized_offset = offset % nitems;
/* Number of bytes in first copy segment */
- first_copy_bytes = ((nitems - tail_plus_offset) < total_copy_bytes)
- ? (nitems - tail_plus_offset) : total_copy_bytes;
+ first_copy_bytes = ((nitems - normalized_offset) < total_copy_bytes)
+ ? (nitems - normalized_offset) : total_copy_bytes;
- clib_memcpy (&f->data[tail_plus_offset], copy_from_here, first_copy_bytes);
+ clib_memcpy (&f->data[normalized_offset], copy_from_here, first_copy_bytes);
/* Number of bytes in second copy segment, if any */
second_copy_bytes = total_copy_bytes - first_copy_bytes;
if (second_copy_bytes)
{
- tail_plus_offset += first_copy_bytes;
- tail_plus_offset %= nitems;
+ normalized_offset += first_copy_bytes;
+ normalized_offset %= nitems;
- ASSERT (tail_plus_offset == 0);
+ ASSERT (normalized_offset == 0);
- clib_memcpy (&f->data[tail_plus_offset],
+ clib_memcpy (&f->data[normalized_offset],
copy_from_here + first_copy_bytes, second_copy_bytes);
}
@@ -573,8 +617,8 @@ format_svm_fifo (u8 * s, va_list * args)
ooo_segment_t *seg;
u32 seg_index;
- s =
- format (s, "ooo pool %d active elts\n", pool_elts (f->ooo_segments));
+ s = format (s, "ooo pool %d active elts\n",
+ pool_elts (f->ooo_segments));
seg_index = f->ooos_list_head;
@@ -582,13 +626,25 @@ format_svm_fifo (u8 * s, va_list * args)
{
seg = pool_elt_at_index (f->ooo_segments, seg_index);
s = format (s, " pos %u, len %u next %d\n",
- seg->fifo_position, seg->length, seg->next);
+ seg->start, seg->length, seg->next);
seg_index = seg->next;
}
}
return s;
}
+u32
+svm_fifo_number_ooo_segments (svm_fifo_t * f)
+{
+ return pool_elts (f->ooo_segments);
+}
+
+ooo_segment_t *
+svm_fifo_first_ooo_segment (svm_fifo_t * f)
+{
+ return pool_elt_at_index (f->ooo_segments, f->ooos_list_head);
+}
+
/*
* fd.io coding-style-patch-verification: ON
*