fss->virtual_mem += n_bytes;
}
-static inline void
-fss_chunk_freelist_lock (fifo_segment_slice_t *fss)
+static inline int
+fss_chunk_fl_index_is_valid (fifo_segment_slice_t *fss, u32 fl_index)
{
- u32 free = 0;
- while (!clib_atomic_cmp_and_swap_acq_relax_n (&fss->chunk_lock, &free, 1, 0))
- {
- /* atomic load limits number of compare_exchange executions */
- while (clib_atomic_load_relax_n (&fss->chunk_lock))
- CLIB_PAUSE ();
- /* on failure, compare_exchange writes (*p)->lock into free */
- free = 0;
- }
+ return (fl_index < FS_CHUNK_VEC_LEN);
}
-static inline void
-fss_chunk_freelist_unlock (fifo_segment_slice_t *fss)
-{
- /* Make sure all reads/writes are complete before releasing the lock */
- clib_atomic_release (&fss->chunk_lock);
-}
+#define FS_CL_HEAD_MASK 0xFFFFFFFFFFFF
+#define FS_CL_HEAD_TMASK 0xFFFF000000000000
+#define FS_CL_HEAD_TINC (1ULL << 48)
-static inline int
-fss_chunk_fl_index_is_valid (fifo_segment_slice_t * fss, u32 fl_index)
+static svm_fifo_chunk_t *
+fss_chunk_free_list_head (fifo_segment_header_t *fsh,
+ fifo_segment_slice_t *fss, u32 fl_index)
{
- return (fl_index < FS_CHUNK_VEC_LEN);
+ fs_sptr_t headsp = clib_atomic_load_relax_n (&fss->free_chunks[fl_index]);
+ return fs_chunk_ptr (fsh, headsp & FS_CL_HEAD_MASK);
}
static void
fifo_segment_slice_t *fss, u32 fl_index,
svm_fifo_chunk_t *c)
{
- fss_chunk_freelist_lock (fss);
- c->next = fss->free_chunks[fl_index];
- fss->free_chunks[fl_index] = fs_chunk_sptr (fsh, c);
- fss_chunk_freelist_unlock (fss);
+ fs_sptr_t old_head, new_head, csp;
+
+ csp = fs_chunk_sptr (fsh, c);
+ ASSERT (csp <= FS_CL_HEAD_MASK);
+ old_head = clib_atomic_load_acq_n (&fss->free_chunks[fl_index]);
+
+ do
+ {
+ c->next = old_head & FS_CL_HEAD_MASK;
+ new_head = csp + ((old_head + FS_CL_HEAD_TINC) & FS_CL_HEAD_TMASK);
+ }
+ while (!clib_atomic_cmp_and_swap_acq_relax (
+ &fss->free_chunks[fl_index], &old_head, &new_head, 1 /* weak */));
}
static void
fifo_segment_slice_t *fss, u32 fl_index,
svm_fifo_chunk_t *head, svm_fifo_chunk_t *tail)
{
- fss_chunk_freelist_lock (fss);
- tail->next = fss->free_chunks[fl_index];
- fss->free_chunks[fl_index] = fs_chunk_sptr (fsh, head);
- fss_chunk_freelist_unlock (fss);
+ fs_sptr_t old_head, new_head, headsp;
+
+ headsp = fs_chunk_sptr (fsh, head);
+ ASSERT (headsp <= FS_CL_HEAD_MASK);
+ old_head = clib_atomic_load_acq_n (&fss->free_chunks[fl_index]);
+
+ do
+ {
+ tail->next = old_head & FS_CL_HEAD_MASK;
+ new_head = headsp + ((old_head + FS_CL_HEAD_TINC) & FS_CL_HEAD_TMASK);
+ }
+ while (!clib_atomic_cmp_and_swap_acq_relax (
+ &fss->free_chunks[fl_index], &old_head, &new_head, 1 /* weak */));
}
static svm_fifo_chunk_t *
fss_chunk_free_list_pop (fifo_segment_header_t *fsh, fifo_segment_slice_t *fss,
u32 fl_index)
{
+ fs_sptr_t old_head, new_head;
svm_fifo_chunk_t *c;
ASSERT (fss_chunk_fl_index_is_valid (fss, fl_index));
- fss_chunk_freelist_lock (fss);
+ old_head = clib_atomic_load_acq_n (&fss->free_chunks[fl_index]);
- if (!fss->free_chunks[fl_index])
+ /* Lock-free stacks are affected by ABA if a side allocates a chunk and
+ * shortly thereafter frees it. To circumvent that, reuse the upper bits
+ * of the head of the list shared pointer, i.e., offset to where the chunk
+ * is, as a tag. The tag is incremented with each push/pop operation and
+ * therefore collisions can only happen if an element is popped and pushed
+ * exactly after a complete wrap of the tag (16 bits). It's unlikely either
+ * of the sides will be descheduled for that long */
+ do
{
- fss_chunk_freelist_unlock (fss);
- return 0;
+ if (!(old_head & FS_CL_HEAD_MASK))
+ return 0;
+ c = fs_chunk_ptr (fsh, old_head & FS_CL_HEAD_MASK);
+ new_head = c->next + ((old_head + FS_CL_HEAD_TINC) & FS_CL_HEAD_TMASK);
}
-
- c = fs_chunk_ptr (fsh, fss->free_chunks[fl_index]);
- fss->free_chunks[fl_index] = c->next;
-
- fss_chunk_freelist_unlock (fss);
+ while (!clib_atomic_cmp_and_swap_acq_relax (
+ &fss->free_chunks[fl_index], &old_head, &new_head, 1 /* weak */));
return c;
}
seg_start = round_pow2_u64 (pointer_to_uword (seg_data), align);
fsh = uword_to_pointer (seg_start, void *);
+ CLIB_MEM_UNPOISON (fsh, seg_sz);
memset (fsh, 0, sizeof (*fsh) + slices_sz);
fsh->byte_index = sizeof (*fsh) + slices_sz;
return pool_elt_at_index (sm->segments, segment_index);
}
+fifo_segment_t *
+fifo_segment_get_segment_if_valid (fifo_segment_main_t *sm, u32 segment_index)
+{
+ if (pool_is_free_index (sm->segments, segment_index))
+ return 0;
+ return pool_elt_at_index (sm->segments, segment_index);
+}
+
void
fifo_segment_info (fifo_segment_t * seg, char **address, size_t * size)
{
if (data_bytes <= fss_fl_chunk_bytes (fss) + n_free)
{
u32 min_size = FIFO_SEGMENT_MIN_FIFO_SIZE;
-
+ if (n_free < min_size)
+ goto done;
batch = (data_bytes - fss_fl_chunk_bytes (fss)) / min_size;
batch = clib_min (batch + 1, n_free / min_size);
if (fsh_try_alloc_chunk_batch (fsh, fss, 0, batch))
}
void
-fs_fifo_free (fifo_segment_t *fs, svm_fifo_t *f)
+fs_fifo_free (fifo_segment_t *fs, svm_fifo_t *f, u32 slice_index)
{
- u32 slice_index = f->shr->slice_index;
fifo_slice_private_t *pfss;
if (CLIB_DEBUG)
for (slice_index = 0; slice_index < fs->n_slices; slice_index++)
clib_mem_bulk_destroy (fs->slices[slice_index].fifos);
+ vec_free (fs->slices);
+
vec_foreach (fs->mqs, mq)
- vec_free (mq->rings);
+ svm_msg_q_cleanup (mq);
vec_free (fs->mqs);
}
f->ooo_enq = f->ooo_deq = 0;
f->prev = 0;
- fs_fifo_free (fs, f);
+ fs_fifo_free (fs, f, f->shr->slice_index);
fsh_active_fifos_update (fsh, -1);
}
+void
+fifo_segment_free_client_fifo (fifo_segment_t *fs, svm_fifo_t *f)
+{
+ fs_fifo_free (fs, f, 0 /* clients attach fifos in slice 0 */);
+}
+
void
fifo_segment_detach_fifo (fifo_segment_t *fs, svm_fifo_t **f)
{
fifo_slice_private_t *pfss;
fifo_segment_slice_t *fss;
- u32 fl_index, slice_index;
- svm_fifo_chunk_t **c;
svm_fifo_t *of = *f;
+ u32 slice_index;
slice_index = of->master_thread_index;
fss = fsh_slice_get (fs->h, slice_index);
if (of->flags & SVM_FIFO_F_LL_TRACKED)
pfss_fifo_del_active_list (pfss, of);
- /* Update slice counts for chunks that were detached */
- vec_foreach (c, of->chunks_at_attach)
- {
- fl_index = fs_freelist_for_size ((*c)->length);
- clib_atomic_fetch_sub_rel (&fss->num_chunks[fl_index], 1);
- }
- vec_free (of->chunks_at_attach);
+ /* Collect chunks that were provided in return for those detached */
+ fsh_slice_collect_chunks (fs->h, fss, of->chunks_at_attach);
+ of->chunks_at_attach = 0;
+
+ /* Collect hdr that was provided in return for the detached */
+ fss_fifo_free_list_push (fs->h, fss, of->hdr_at_attach);
+ of->hdr_at_attach = 0;
clib_mem_bulk_free (pfss->fifos, *f);
*f = 0;
void
fifo_segment_attach_fifo (fifo_segment_t *fs, svm_fifo_t **f, u32 slice_index)
{
+ svm_fifo_chunk_t *c, *nc, *pc = 0;
fifo_slice_private_t *pfss;
fifo_segment_slice_t *fss;
- svm_fifo_chunk_t *c;
svm_fifo_t *nf, *of;
- u32 fl_index;
nf = fs_fifo_alloc (fs, slice_index);
clib_memcpy_fast (nf, *f, sizeof (*nf));
if (nf->flags & SVM_FIFO_F_LL_TRACKED)
pfss_fifo_add_active_list (pfss, nf);
- /* Update allocated chunks for fifo segment and build list
- * of chunks to be freed at detach */
+ /* Allocate shared hdr and chunks to be collected at detach in return
+ * for those that are being attached now */
of = *f;
- of->chunks_at_attach = 0;
+ of->hdr_at_attach = fsh_try_alloc_fifo_hdr (fs->h, fss);
c = fs_chunk_ptr (fs->h, nf->shr->start_chunk);
- while (c)
+ of->chunks_at_attach = pc = fsh_try_alloc_chunk (fs->h, fss, c->length);
+
+ while ((c = fs_chunk_ptr (fs->h, c->next)))
{
- fl_index = fs_freelist_for_size (c->length);
- clib_atomic_fetch_add_rel (&fss->num_chunks[fl_index], 1);
- vec_add1 (of->chunks_at_attach, c);
- c = fs_chunk_ptr (fs->h, c->next);
+ nc = fsh_try_alloc_chunk (fs->h, fss, c->length);
+ pc->next = fs_chunk_sptr (fs->h, nc);
+ pc = nc;
}
nf->shr->slice_index = slice_index;
return (u8 *) f->shr - (u8 *) f->fs_hdr;
}
+svm_fifo_chunk_t *
+fifo_segment_alloc_chunk_w_slice (fifo_segment_t *fs, u32 slice_index,
+ u32 chunk_size)
+{
+ fifo_segment_header_t *fsh = fs->h;
+ fifo_segment_slice_t *fss;
+
+ fss = fsh_slice_get (fsh, slice_index);
+ return fsh_try_alloc_chunk (fsh, fss, chunk_size);
+}
+
+void
+fifo_segment_collect_chunk (fifo_segment_t *fs, u32 slice_index,
+ svm_fifo_chunk_t *c)
+{
+ fsh_collect_chunks (fs->h, slice_index, c);
+}
+
+uword
+fifo_segment_chunk_offset (fifo_segment_t *fs, svm_fifo_chunk_t *c)
+{
+ return (u8 *) c - (u8 *) fs->h;
+}
+
svm_msg_q_t *
fifo_segment_msg_q_alloc (fifo_segment_t *fs, u32 mq_index,
svm_msg_q_cfg_t *cfg)
{
for (i = 0; i < FS_CHUNK_VEC_LEN; i++)
{
- c = fs_chunk_ptr (fsh, fss->free_chunks[i]);
+ c = fss_chunk_free_list_head (fsh, fss, i);
if (c == 0)
continue;
if (fl_index >= FS_CHUNK_VEC_LEN)
return 0;
- c = fs_chunk_ptr (fsh, fss->free_chunks[fl_index]);
+ c = fss_chunk_free_list_head (fsh, fss, fl_index);
if (c == 0)
return 0;
fss = fsh_slice_get (fsh, slice_index);
for (i = 0; i < FS_CHUNK_VEC_LEN; i++)
{
- c = fs_chunk_ptr (fsh, fss->free_chunks[i]);
+ c = fss_chunk_free_list_head (fsh, fss, i);
if (c == 0 && fss->num_chunks[i] == 0)
continue;
count = 0;
format_memory_size, chunk_bytes, chunk_bytes,
format_memory_size, est_chunk_bytes, est_chunk_bytes,
format_memory_size, tracked_cached_bytes, tracked_cached_bytes);
- s = format (s, "%Ufifo active: %u hdr free bytes: %U (%u) \n",
- format_white_space, indent + 2, fsh->n_active_fifos,
+ s = format (s, "%Ufifo active: %u hdr free: %u bytes: %U (%u) \n",
+ format_white_space, indent + 2, fsh->n_active_fifos, free_fifos,
format_memory_size, fifo_hdr, fifo_hdr);
s = format (s, "%Usegment usage: %.2f%% (%U / %U) virt: %U status: %s\n",
format_white_space, indent + 2, usage, format_memory_size,
Code Review / vpp.git / blobdiff