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Introduce l{2,3,4}_hdr_offset fields in the buffer metadata

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To save space in the first cacheline following is changed:

- total_length_not_including_first_buffer moved to the 2nd cacheline.
This field is used only when VLIB_BUFFER_TOTAL_LENGTH_VALID and
VLIB_BUFFER_NEXT_PRESENT are both set.

- free_list_index is now stored in 4bits inside flags, which
allows up to 16 free lists. In case we need more we can store index
in the 2nd cachelin

Change-Id: Ic8521350819391af470d31d3fa1013e67ecb7681
Signed-off-by: Damjan Marion <damarion@cisco.com>
This commit is contained in:
Damjan Marion
2017-07-13 18:53:27 +02:00
committed by Dave Barach
parent 0f09b77778
commit 072401e809
16 changed files with 111 additions and 92 deletions
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50
src/vlib/buffer_funcs.h
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@ -106,12 +106,15 @@ uword vlib_buffer_length_in_chain_slow_path (vlib_main_t * vm,
always_inline uword
vlib_buffer_length_in_chain (vlib_main_t * vm, vlib_buffer_t * b)
{
uword l = b->current_length + b->total_length_not_including_first_buffer;
if (PREDICT_FALSE ((b->flags & (VLIB_BUFFER_NEXT_PRESENT
| VLIB_BUFFER_TOTAL_LENGTH_VALID))
== VLIB_BUFFER_NEXT_PRESENT))
return vlib_buffer_length_in_chain_slow_path (vm, b);
return l;
uword len = b->current_length;
if (PREDICT_TRUE ((b->flags & VLIB_BUFFER_NEXT_PRESENT) == 0))
return len;
if (PREDICT_TRUE (b->flags & VLIB_BUFFER_TOTAL_LENGTH_VALID))
return len + b->total_length_not_including_first_buffer;
return vlib_buffer_length_in_chain_slow_path (vm, b);
}
/** \brief Get length in bytes of the buffer index buffer chain
@ -261,6 +264,24 @@ vlib_buffer_round_size (u32 size)
return round_pow2 (size, sizeof (vlib_buffer_t));
}
always_inline u32
vlib_buffer_get_free_list_index (vlib_buffer_t * b)
{
return b->flags & VLIB_BUFFER_FREE_LIST_INDEX_MASK;
}
always_inline void
vlib_buffer_set_free_list_index (vlib_buffer_t * b, u32 index)
{
/* if there is an need for more free lists we should consider
storig data in the 2nd cacheline */
ASSERT (VLIB_BUFFER_FREE_LIST_INDEX_MASK & 1);
ASSERT (index <= VLIB_BUFFER_FREE_LIST_INDEX_MASK);
b->flags &= ~VLIB_BUFFER_FREE_LIST_INDEX_MASK;
b->flags |= index & VLIB_BUFFER_FREE_LIST_INDEX_MASK;
}
/** \brief Allocate buffers from specific freelist into supplied array
@param vm - (vlib_main_t *) vlib main data structure pointer
@ -381,7 +402,7 @@ vlib_buffer_get_buffer_free_list (vlib_main_t * vm, vlib_buffer_t * b,
vlib_buffer_main_t *bm = vm->buffer_main;
u32 i;
*index = i = b->free_list_index;
*index = i = vlib_buffer_get_free_list_index (b);
return pool_elt_at_index (bm->buffer_free_list_pool, i);
}
@ -569,7 +590,8 @@ vlib_buffer_clone (vlib_main_t * vm, u32 src_buffer, u32 * buffers,
}
n_buffers = vlib_buffer_alloc_from_free_list (vm, buffers, n_buffers,
s->free_list_index);
vlib_buffer_get_free_list_index
(s));
if (PREDICT_FALSE (n_buffers == 0))
{
buffers[0] = src_buffer;
@ -581,7 +603,8 @@ vlib_buffer_clone (vlib_main_t * vm, u32 src_buffer, u32 * buffers,
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;
vlib_buffer_set_free_list_index (d,
vlib_buffer_get_free_list_index (s));
d->total_length_not_including_first_buffer =
s->total_length_not_including_first_buffer + s->current_length -
head_end_offset;
@ -615,7 +638,8 @@ 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);
ASSERT (vlib_buffer_get_free_list_index (head) ==
vlib_buffer_get_free_list_index (tail));
head->flags |= VLIB_BUFFER_NEXT_PRESENT;
head->flags &= ~VLIB_BUFFER_TOTAL_LENGTH_VALID;
@ -791,7 +815,7 @@ vlib_buffer_init_for_free_list (vlib_buffer_t * dst,
CLIB_CACHE_LINE_BYTES * 2);
/* Make sure buffer template is sane. */
ASSERT (fl->index == fl->buffer_init_template.free_list_index);
ASSERT (fl->index == vlib_buffer_get_free_list_index (src));
clib_memcpy (STRUCT_MARK_PTR (dst, template_start),
STRUCT_MARK_PTR (src, template_start),
@ -806,7 +830,6 @@ vlib_buffer_init_for_free_list (vlib_buffer_t * dst,
_(current_data);
_(current_length);
_(flags);
_(free_list_index);
#undef _
ASSERT (dst->total_length_not_including_first_buffer == 0);
ASSERT (dst->n_add_refs == 0);
@ -832,7 +855,7 @@ vlib_buffer_init_two_for_free_list (vlib_buffer_t * dst0,
vlib_buffer_t *src = &fl->buffer_init_template;
/* Make sure buffer template is sane. */
ASSERT (fl->index == fl->buffer_init_template.free_list_index);
ASSERT (fl->index == vlib_buffer_get_free_list_index (src));
clib_memcpy (STRUCT_MARK_PTR (dst0, template_start),
STRUCT_MARK_PTR (src, template_start),
@ -853,7 +876,6 @@ vlib_buffer_init_two_for_free_list (vlib_buffer_t * dst0,
_(current_data);
_(current_length);
_(flags);
_(free_list_index);
#undef _
ASSERT (dst0->total_length_not_including_first_buffer == 0);