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ofp-actions: Waste less memory in learn actions.

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Make the immediate data member 'src_imm' of a learn spec allocated at
the end of the action for just the right size.  This, together with
some structure packing saves on average of ~128 bytes for each learn
spec in each learn action.  Typical learn actions have about 4 specs
each, so this amounts to saving about 0.5kb for each learn action.

Signed-off-by: Jarno Rajahalme <jarno@ovn.org>
Acked-by: Ben Pfaff <blp@ovn.org>
This commit is contained in:
Jarno Rajahalme
2016-08-31 08:43:48 -07:00
parent 47bf118665
commit dfe191d5fa
5 changed files with 114 additions and 54 deletions
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72
lib/learn.c
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@@ -41,7 +41,8 @@ learn_check(const struct ofpact_learn *learn, const struct flow *flow)
struct match match;
match_init_catchall(&match);
for (spec = learn->specs; spec < &learn->specs[learn->n_specs]; spec++) {
for (spec = learn->specs; spec < &learn->specs[learn->n_specs];
spec = ofpact_learn_spec_next(spec)) {
enum ofperr error;
/* Check the source. */
@@ -59,8 +60,7 @@ learn_check(const struct ofpact_learn *learn, const struct flow *flow)
if (error) {
return error;
}
mf_write_subfield(&spec->dst, &spec->src_imm, &match);
mf_write_subfield_value(&spec->dst, spec->src_imm, &match);
break;
case NX_LEARN_DST_LOAD:
@@ -120,14 +120,15 @@ learn_execute(const struct ofpact_learn *learn, const struct flow *flow,
oft->fin_hard_timeout = learn->fin_hard_timeout;
}
for (spec = learn->specs; spec < &learn->specs[learn->n_specs]; spec++) {
for (spec = learn->specs; spec < &learn->specs[learn->n_specs];
spec = ofpact_learn_spec_next(spec)) {
struct ofpact_set_field *sf;
union mf_subvalue value;
if (spec->src_type == NX_LEARN_SRC_FIELD) {
mf_read_subfield(&spec->src, flow, &value);
} else {
value = spec->src_imm;
mf_subvalue_from_value(&spec->dst, &value, spec->src_imm);
}
switch (spec->dst_type) {
@@ -175,7 +176,8 @@ learn_mask(const struct ofpact_learn *learn, struct flow_wildcards *wc)
union mf_subvalue value;
memset(&value, 0xff, sizeof value);
for (spec = learn->specs; spec < &learn->specs[learn->n_specs]; spec++) {
for (spec = learn->specs; spec < &learn->specs[learn->n_specs];
spec = ofpact_learn_spec_next(spec)) {
if (spec->src_type == NX_LEARN_SRC_FIELD) {
mf_write_subfield_flow(&spec->src, &value, &wc->masks);
}
@@ -185,7 +187,8 @@ learn_mask(const struct ofpact_learn *learn, struct flow_wildcards *wc)
/* Returns NULL if successful, otherwise a malloc()'d string describing the
* error. The caller is responsible for freeing the returned string. */
static char * OVS_WARN_UNUSED_RESULT
learn_parse_load_immediate(const char *s, struct ofpact_learn_spec *spec)
learn_parse_load_immediate(const char *s, struct ofpact_learn_spec *spec,
struct ofpbuf *ofpacts)
{
const char *full_s = s;
struct mf_subfield dst;
@@ -220,9 +223,14 @@ learn_parse_load_immediate(const char *s, struct ofpact_learn_spec *spec)
spec->n_bits = dst.n_bits;
spec->src_type = NX_LEARN_SRC_IMMEDIATE;
spec->src_imm = imm;
spec->dst_type = NX_LEARN_DST_LOAD;
spec->dst = dst;
/* Push value last, as this may reallocate 'spec'! */
unsigned int n_bytes = DIV_ROUND_UP(dst.n_bits, 8);
uint8_t *src_imm = ofpbuf_put_zeros(ofpacts, OFPACT_ALIGN(n_bytes));
memcpy(src_imm, &imm.u8[sizeof imm.u8 - n_bytes], n_bytes);
return NULL;
}
@@ -230,7 +238,8 @@ learn_parse_load_immediate(const char *s, struct ofpact_learn_spec *spec)
* error. The caller is responsible for freeing the returned string. */
static char * OVS_WARN_UNUSED_RESULT
learn_parse_spec(const char *orig, char *name, char *value,
struct ofpact_learn_spec *spec)
struct ofpact_learn_spec *spec,
struct ofpbuf *ofpacts, struct match *match)
{
if (mf_from_name(name)) {
const struct mf_field *dst = mf_from_name(name);
@@ -244,13 +253,19 @@ learn_parse_spec(const char *orig, char *name, char *value,
spec->n_bits = dst->n_bits;
spec->src_type = NX_LEARN_SRC_IMMEDIATE;
memset(&spec->src_imm, 0, sizeof spec->src_imm);
memcpy(&spec->src_imm.u8[sizeof spec->src_imm - dst->n_bytes],
&imm, dst->n_bytes);
spec->dst_type = NX_LEARN_DST_MATCH;
spec->dst.field = dst;
spec->dst.ofs = 0;
spec->dst.n_bits = dst->n_bits;
/* Update 'match' to allow for satisfying destination
* prerequisites. */
mf_set_value(dst, &imm, match, NULL);
/* Push value last, as this may reallocate 'spec'! */
uint8_t *src_imm = ofpbuf_put_zeros(ofpacts,
OFPACT_ALIGN(dst->n_bytes));
memcpy(src_imm, &imm, dst->n_bytes);
} else if (strchr(name, '[')) {
/* Parse destination and check prerequisites. */
char *error;
@@ -284,7 +299,7 @@ learn_parse_spec(const char *orig, char *name, char *value,
spec->dst_type = NX_LEARN_DST_MATCH;
} else if (!strcmp(name, "load")) {
if (value[strcspn(value, "[-")] == '-') {
char *error = learn_parse_load_immediate(value, spec);
char *error = learn_parse_load_immediate(value, spec, ofpacts);
if (error) {
return error;
}
@@ -363,20 +378,12 @@ learn_parse__(char *orig, char *arg, struct ofpbuf *ofpacts)
char *error;
spec = ofpbuf_put_zeros(ofpacts, sizeof *spec);
learn = ofpacts->header;
learn->n_specs++;
error = learn_parse_spec(orig, name, value, spec);
error = learn_parse_spec(orig, name, value, spec, ofpacts, &match);
if (error) {
return error;
}
/* Update 'match' to allow for satisfying destination
* prerequisites. */
if (spec->src_type == NX_LEARN_SRC_IMMEDIATE
&& spec->dst_type == NX_LEARN_DST_MATCH) {
mf_write_subfield(&spec->dst, &spec->src_imm, &match);
}
learn = ofpacts->header;
learn->n_specs++;
}
}
ofpact_finish_LEARN(ofpacts, &learn);
@@ -449,19 +456,20 @@ learn_format(const struct ofpact_learn *learn, struct ds *s)
colors.param, colors.end, ntohll(learn->cookie));
}
for (spec = learn->specs; spec < &learn->specs[learn->n_specs]; spec++) {
for (spec = learn->specs; spec < &learn->specs[learn->n_specs];
spec = ofpact_learn_spec_next(spec)) {
unsigned int n_bytes = DIV_ROUND_UP(spec->dst.n_bits, 8);
ds_put_char(s, ',');
switch (spec->src_type | spec->dst_type) {
case NX_LEARN_SRC_IMMEDIATE | NX_LEARN_DST_MATCH:
case NX_LEARN_SRC_IMMEDIATE | NX_LEARN_DST_MATCH: {
if (spec->dst.ofs == 0
&& spec->dst.n_bits == spec->dst.field->n_bits) {
union mf_value value;
memset(&value, 0, sizeof value);
bitwise_copy(&spec->src_imm, sizeof spec->src_imm, 0,
&value, spec->dst.field->n_bytes, 0,
spec->dst.field->n_bits);
memcpy(&value.b[spec->dst.field->n_bytes - n_bytes],
spec->src_imm, n_bytes);
ds_put_format(s, "%s%s=%s", colors.param,
spec->dst.field->name, colors.end);
mf_format(spec->dst.field, &value, NULL, s);
@@ -469,10 +477,10 @@ learn_format(const struct ofpact_learn *learn, struct ds *s)
ds_put_format(s, "%s", colors.param);
mf_format_subfield(&spec->dst, s);
ds_put_format(s, "=%s", colors.end);
mf_format_subvalue(&spec->src_imm, s);
ds_put_hex(s, spec->src_imm, n_bytes);
}
break;
}
case NX_LEARN_SRC_FIELD | NX_LEARN_DST_MATCH:
ds_put_format(s, "%s", colors.param);
mf_format_subfield(&spec->dst, s);
@@ -486,7 +494,7 @@ learn_format(const struct ofpact_learn *learn, struct ds *s)
case NX_LEARN_SRC_IMMEDIATE | NX_LEARN_DST_LOAD:
ds_put_format(s, "%sload:%s", colors.special, colors.end);
mf_format_subvalue(&spec->src_imm, s);
ds_put_hex(s, spec->src_imm, n_bytes);
ds_put_format(s, "%s->%s", colors.special, colors.end);
mf_format_subfield(&spec->dst, s);
break;