From c47ed032c6d036a9f942fc9ced48874fad55b48c Mon Sep 17 00:00:00 2001 From: Damjan Marion Date: Wed, 25 Jan 2017 14:18:03 +0100 Subject: vlib: add buffer cloning support Change-Id: I50070611af15b2b4cc29664a8bee4f821ac3c835 Signed-off-by: Damjan Marion --- src/vlib/buffer.c | 254 +++++++++++------------------------------------- src/vlib/buffer.h | 4 +- src/vlib/buffer_funcs.h | 113 ++++++++++++++++++++- 3 files changed, 171 insertions(+), 200 deletions(-) (limited to 'src/vlib') diff --git a/src/vlib/buffer.c b/src/vlib/buffer.c index 95b4344f10b..4f5eb09da91 100644 --- a/src/vlib/buffer.c +++ b/src/vlib/buffer.c @@ -68,8 +68,9 @@ format_vlib_buffer (u8 * s, va_list * args) vlib_buffer_t *b = va_arg (*args, vlib_buffer_t *); uword indent = format_get_indent (s); - s = format (s, "current data %d, length %d, free-list %d", - b->current_data, b->current_length, b->free_list_index); + s = format (s, "current data %d, length %d, free-list %d, clone-count %u", + b->current_data, b->current_length, b->free_list_index, + b->n_add_refs); if (b->flags & VLIB_BUFFER_TOTAL_LENGTH_VALID) s = format (s, ", totlen-nifb %d", @@ -84,8 +85,10 @@ format_vlib_buffer (u8 * s, va_list * args) u32 next_buffer = b->next_buffer; b = vlib_get_buffer (vm, next_buffer); - s = format (s, "\n%Unext-buffer 0x%x, segment length %d", - format_white_space, indent, next_buffer, b->current_length); + s = + format (s, "\n%Unext-buffer 0x%x, segment length %d, clone-count %u", + format_white_space, indent, next_buffer, b->current_length, + b->n_add_refs); } return s; @@ -262,7 +265,7 @@ vlib_main_t **vlib_mains; /* When dubugging validate that given buffers are either known allocated or known free. */ -static void __attribute__ ((unused)) +static void vlib_buffer_validate_alloc_free (vlib_main_t * vm, u32 * buffers, uword n_buffers, @@ -362,6 +365,7 @@ vlib_buffer_create_free_list_helper (vlib_main_t * vm, /* Setup free buffer template. */ f->buffer_init_template.free_list_index = f->index; + f->buffer_init_template.n_add_refs = 0; if (is_public) { @@ -620,19 +624,11 @@ vlib_buffer_free_inline (vlib_main_t * vm, { vlib_buffer_main_t *bm = vm->buffer_main; vlib_buffer_free_list_t *fl; - static u32 *next_to_free[2]; /* smp bad */ - u32 i_next_to_free, *b, *n, *f, fi; - uword n_left; + u32 fi; int i; - static vlib_buffer_free_list_t **announce_list; - vlib_buffer_free_list_t *fl0 = 0, *fl1 = 0; - u32 bi0 = (u32) ~ 0, bi1 = (u32) ~ 0, fi0, fi1 = (u32) ~ 0; - u8 free0, free1 = 0, free_next0, free_next1; u32 (*cb) (vlib_main_t * vm, u32 * buffers, u32 n_buffers, u32 follow_buffer_next); - ASSERT (os_get_cpu_number () == 0); - cb = bm->buffer_free_callback; if (PREDICT_FALSE (cb != 0)) @@ -641,203 +637,68 @@ vlib_buffer_free_inline (vlib_main_t * vm, if (!n_buffers) return; - /* Use first buffer to get default free list. */ - { - u32 bi0 = buffers[0]; - vlib_buffer_t *b0; - - b0 = vlib_get_buffer (vm, bi0); - fl = vlib_buffer_get_buffer_free_list (vm, b0, &fi); - if (fl->buffers_added_to_freelist_function) - vec_add1 (announce_list, fl); - } - - vec_validate (next_to_free[0], n_buffers - 1); - vec_validate (next_to_free[1], n_buffers - 1); - - i_next_to_free = 0; - n_left = n_buffers; - b = buffers; - -again: - /* Verify that buffers are known allocated. */ - vlib_buffer_validate_alloc_free (vm, b, - n_left, VLIB_BUFFER_KNOWN_ALLOCATED); - - vec_add2_aligned (fl->buffers, f, n_left, CLIB_CACHE_LINE_BYTES); - - n = next_to_free[i_next_to_free]; - while (n_left >= 4) - { - vlib_buffer_t *b0, *b1, *binit0, *binit1, dummy_buffers[2]; - - bi0 = b[0]; - bi1 = b[1]; - - f[0] = bi0; - f[1] = bi1; - f += 2; - b += 2; - n_left -= 2; - - /* Prefetch buffers for next iteration. */ - vlib_prefetch_buffer_with_index (vm, b[0], WRITE); - vlib_prefetch_buffer_with_index (vm, b[1], WRITE); - - b0 = vlib_get_buffer (vm, bi0); - b1 = vlib_get_buffer (vm, bi1); - - free0 = (b0->flags & VLIB_BUFFER_RECYCLE) == 0; - free1 = (b1->flags & VLIB_BUFFER_RECYCLE) == 0; - - /* Must be before init which will over-write buffer flags. */ - if (follow_buffer_next) - { - n[0] = b0->next_buffer; - free_next0 = free0 && (b0->flags & VLIB_BUFFER_NEXT_PRESENT) != 0; - n += free_next0; - - n[0] = b1->next_buffer; - free_next1 = free1 && (b1->flags & VLIB_BUFFER_NEXT_PRESENT) != 0; - n += free_next1; - } - else - free_next0 = free_next1 = 0; - - /* Must be before init which will over-write buffer free list. */ - fi0 = b0->free_list_index; - fi1 = b1->free_list_index; - - if (PREDICT_FALSE (fi0 != fi || fi1 != fi)) - goto slow_path_x2; - - binit0 = free0 ? b0 : &dummy_buffers[0]; - binit1 = free1 ? b1 : &dummy_buffers[1]; - - vlib_buffer_init_two_for_free_list (binit0, binit1, fl); - continue; - - slow_path_x2: - /* Backup speculation. */ - f -= 2; - n -= free_next0 + free_next1; - - _vec_len (fl->buffers) = f - fl->buffers; - - fl0 = pool_elt_at_index (bm->buffer_free_list_pool, fi0); - fl1 = pool_elt_at_index (bm->buffer_free_list_pool, fi1); - - vlib_buffer_add_to_free_list (vm, fl0, bi0, free0); - if (PREDICT_FALSE (fl0->buffers_added_to_freelist_function != 0)) - { - int i; - for (i = 0; i < vec_len (announce_list); i++) - if (fl0 == announce_list[i]) - goto no_fl0; - vec_add1 (announce_list, fl0); - } - no_fl0: - if (PREDICT_FALSE (fl1->buffers_added_to_freelist_function != 0)) - { - int i; - for (i = 0; i < vec_len (announce_list); i++) - if (fl1 == announce_list[i]) - goto no_fl1; - vec_add1 (announce_list, fl1); - } - - no_fl1: - vlib_buffer_add_to_free_list (vm, fl1, bi1, free1); - - /* Possibly change current free list. */ - if (fi0 != fi && fi1 != fi) - { - fi = fi1; - fl = pool_elt_at_index (bm->buffer_free_list_pool, fi); - } - - vec_add2_aligned (fl->buffers, f, n_left, CLIB_CACHE_LINE_BYTES); - } - - while (n_left >= 1) + for (i = 0; i < n_buffers; i++) { - vlib_buffer_t *b0, *binit0, dummy_buffers[1]; + vlib_buffer_t *b; + u32 bi = buffers[i]; - bi0 = b[0]; - f[0] = bi0; - f += 1; - b += 1; - n_left -= 1; - - b0 = vlib_get_buffer (vm, bi0); + b = vlib_get_buffer (vm, bi); - free0 = (b0->flags & VLIB_BUFFER_RECYCLE) == 0; + fl = vlib_buffer_get_buffer_free_list (vm, b, &fi); - /* Must be before init which will over-write buffer flags. */ - if (follow_buffer_next) + /* The only current use of this callback: multicast recycle */ + if (PREDICT_FALSE (fl->buffers_added_to_freelist_function != 0)) { - n[0] = b0->next_buffer; - free_next0 = free0 && (b0->flags & VLIB_BUFFER_NEXT_PRESENT) != 0; - n += free_next0; + int j; + + vlib_buffer_add_to_free_list + (vm, fl, buffers[i], (b->flags & VLIB_BUFFER_RECYCLE) == 0); + + for (j = 0; j < vec_len (bm->announce_list); j++) + { + if (fl == bm->announce_list[j]) + goto already_announced; + } + vec_add1 (bm->announce_list, fl); + already_announced: + ; } else - free_next0 = 0; - - /* Must be before init which will over-write buffer free list. */ - fi0 = b0->free_list_index; - - if (PREDICT_FALSE (fi0 != fi)) - goto slow_path_x1; - - binit0 = free0 ? b0 : &dummy_buffers[0]; - - vlib_buffer_init_for_free_list (binit0, fl); - continue; - - slow_path_x1: - /* Backup speculation. */ - f -= 1; - n -= free_next0; - - _vec_len (fl->buffers) = f - fl->buffers; - - fl0 = pool_elt_at_index (bm->buffer_free_list_pool, fi0); - - vlib_buffer_add_to_free_list (vm, fl0, bi0, free0); - if (PREDICT_FALSE (fl0->buffers_added_to_freelist_function != 0)) { - int i; - for (i = 0; i < vec_len (announce_list); i++) - if (fl0 == announce_list[i]) - goto no_fl00; - vec_add1 (announce_list, fl0); + if (PREDICT_TRUE ((b->flags & VLIB_BUFFER_RECYCLE) == 0)) + { + u32 flags, next; + + do + { + vlib_buffer_t *nb = vlib_get_buffer (vm, bi); + flags = nb->flags; + next = nb->next_buffer; + if (nb->n_add_refs) + nb->n_add_refs--; + else + { + vlib_buffer_validate_alloc_free (vm, &bi, 1, + VLIB_BUFFER_KNOWN_ALLOCATED); + vlib_buffer_add_to_free_list (vm, fl, bi, 1); + } + bi = next; + } + while (follow_buffer_next + && (flags & VLIB_BUFFER_NEXT_PRESENT)); + + } } - - no_fl00: - fi = fi0; - fl = pool_elt_at_index (bm->buffer_free_list_pool, fi); - - vec_add2_aligned (fl->buffers, f, n_left, CLIB_CACHE_LINE_BYTES); } - - if (follow_buffer_next && ((n_left = n - next_to_free[i_next_to_free]) > 0)) - { - b = next_to_free[i_next_to_free]; - i_next_to_free ^= 1; - goto again; - } - - _vec_len (fl->buffers) = f - fl->buffers; - - if (vec_len (announce_list)) + if (vec_len (bm->announce_list)) { vlib_buffer_free_list_t *fl; - for (i = 0; i < vec_len (announce_list); i++) + for (i = 0; i < vec_len (bm->announce_list); i++) { - fl = announce_list[i]; + fl = bm->announce_list[i]; fl->buffers_added_to_freelist_function (vm, fl); } - _vec_len (announce_list) = 0; + _vec_len (bm->announce_list) = 0; } } @@ -922,6 +783,7 @@ vlib_packet_template_init (vlib_main_t * vm, fl->buffer_init_template.current_data = 0; fl->buffer_init_template.current_length = n_packet_data_bytes; fl->buffer_init_template.flags = 0; + fl->buffer_init_template.n_add_refs = 0; vlib_worker_thread_barrier_release (vm); } diff --git a/src/vlib/buffer.h b/src/vlib/buffer.h index 8ea79502455..b4015b302c3 100644 --- a/src/vlib/buffer.h +++ b/src/vlib/buffer.h @@ -119,7 +119,9 @@ typedef struct feature node */ - u8 dont_waste_me[3]; /**< Available space in the (precious) + u8 n_add_refs; /**< Number of additional references to this buffer. */ + + u8 dont_waste_me[2]; /**< Available space in the (precious) first 32 octets of buffer metadata Before allocating any of it, discussion required! */ diff --git a/src/vlib/buffer_funcs.h b/src/vlib/buffer_funcs.h index 0b583a61994..e0fde5f2194 100644 --- a/src/vlib/buffer_funcs.h +++ b/src/vlib/buffer_funcs.h @@ -530,6 +530,110 @@ vlib_buffer_copy (vlib_main_t * vm, vlib_buffer_t * b) return fd; } +/** \brief Create multiple clones of buffer and store them in the supplied array + + @param vm - (vlib_main_t *) vlib main data structure pointer + @param src_buffer - (u32) source buffer index + @param buffers - (u32 * ) buffer index array + @param n_buffers - (u8) number of buffer clones requested + @param head_end_offset - (u16) offset relative to current position + where packet head ends + @return - (u8) number of buffers actually cloned, may be + less than the number requested or zero +*/ + +always_inline u8 +vlib_buffer_clone (vlib_main_t * vm, u32 src_buffer, u32 * buffers, + u8 n_buffers, u16 head_end_offset) +{ + u8 i; + vlib_buffer_t *s = vlib_get_buffer (vm, src_buffer); + + ASSERT (s->n_add_refs == 0); + ASSERT (n_buffers); + + if (s->current_length <= head_end_offset + CLIB_CACHE_LINE_BYTES * 2) + { + buffers[0] = src_buffer; + for (i = 1; i < n_buffers; i++) + { + vlib_buffer_t *d; + d = vlib_buffer_copy (vm, s); + if (d == 0) + return i; + buffers[i] = vlib_get_buffer_index (vm, d); + + } + return n_buffers; + } + + n_buffers = vlib_buffer_alloc_from_free_list (vm, buffers, n_buffers, + s->free_list_index); + if (PREDICT_FALSE (n_buffers == 0)) + { + buffers[0] = src_buffer; + return 1; + } + + for (i = 0; i < n_buffers; i++) + { + vlib_buffer_t *d = vlib_get_buffer (vm, buffers[i]); + d->current_data = s->current_data; + d->current_length = head_end_offset; + d->free_list_index = s->free_list_index; + d->total_length_not_including_first_buffer = + s->total_length_not_including_first_buffer + s->current_length - + head_end_offset; + d->flags = s->flags | VLIB_BUFFER_NEXT_PRESENT; + d->flags &= ~VLIB_BUFFER_EXT_HDR_VALID; + clib_memcpy (d->opaque, s->opaque, sizeof (s->opaque)); + clib_memcpy (vlib_buffer_get_current (d), vlib_buffer_get_current (s), + head_end_offset); + d->next_buffer = src_buffer; + } + vlib_buffer_advance (s, head_end_offset); + s->n_add_refs = n_buffers - 1; + while (s->flags & VLIB_BUFFER_NEXT_PRESENT) + { + s = vlib_get_buffer (vm, s->next_buffer); + s->n_add_refs = n_buffers - 1; + } + + return n_buffers; +} + +/** \brief Attach cloned tail to the buffer + + @param vm - (vlib_main_t *) vlib main data structure pointer + @param head - (vlib_buffer_t *) head buffer + @param tail - (Vlib buffer_t *) tail buffer to clone and attach to head +*/ + +always_inline void +vlib_buffer_attach_clone (vlib_main_t * vm, vlib_buffer_t * head, + vlib_buffer_t * tail) +{ + ASSERT ((head->flags & VLIB_BUFFER_NEXT_PRESENT) == 0); + ASSERT (head->free_list_index == tail->free_list_index); + + head->flags |= VLIB_BUFFER_NEXT_PRESENT; + head->flags &= ~VLIB_BUFFER_TOTAL_LENGTH_VALID; + head->flags &= ~VLIB_BUFFER_EXT_HDR_VALID; + head->flags |= (tail->flags & VLIB_BUFFER_TOTAL_LENGTH_VALID); + head->next_buffer = vlib_get_buffer_index (vm, tail); + head->total_length_not_including_first_buffer = tail->current_length + + tail->total_length_not_including_first_buffer; + +next_segment: + __sync_add_and_fetch (&tail->n_add_refs, 1); + + if (tail->flags & VLIB_BUFFER_NEXT_PRESENT) + { + tail = vlib_get_buffer (vm, tail->next_buffer); + goto next_segment; + } +} + /* Initializes the buffer as an empty packet with no chained buffers. */ always_inline void vlib_buffer_chain_init (vlib_buffer_t * first) @@ -695,7 +799,8 @@ vlib_buffer_init_for_free_list (vlib_buffer_t * dst, _(flags); _(free_list_index); #undef _ - ASSERT (dst->total_length_not_including_first_buffer == 0); + dst->total_length_not_including_first_buffer = 0; + ASSERT (dst->n_add_refs == 0); } always_inline void @@ -727,8 +832,10 @@ vlib_buffer_init_two_for_free_list (vlib_buffer_t * dst0, _(flags); _(free_list_index); #undef _ - ASSERT (dst0->total_length_not_including_first_buffer == 0); - ASSERT (dst1->total_length_not_including_first_buffer == 0); + dst0->total_length_not_including_first_buffer = 0; + dst1->total_length_not_including_first_buffer = 0; + ASSERT (dst0->n_add_refs == 0); + ASSERT (dst1->n_add_refs == 0); } #if CLIB_DEBUG > 0 -- cgit 1.2.3-korg