s390/debug: only write data once
debug_event_common memsets the active debug entry with zeros to prevent stale data leakage. This is overwritten with the actual debug data in the next step. Only write zeros to that part of the debug entry that's not used by new debug data. Micro benchmarks show a 2-10% reduction of cpu cycles with this approach. Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Acked-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
parent
94158e544f
commit
0dcd91a9e6
|
@ -902,8 +902,9 @@ debug_entry_t *debug_event_common(debug_info_t *id, int level, const void *buf,
|
||||||
}
|
}
|
||||||
do {
|
do {
|
||||||
active = get_active_entry(id);
|
active = get_active_entry(id);
|
||||||
memset(DEBUG_DATA(active), 0, id->buf_size);
|
|
||||||
memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
|
memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
|
||||||
|
if (len < id->buf_size)
|
||||||
|
memset((DEBUG_DATA(active)) + len, 0, id->buf_size - len);
|
||||||
debug_finish_entry(id, active, level, 0);
|
debug_finish_entry(id, active, level, 0);
|
||||||
len -= id->buf_size;
|
len -= id->buf_size;
|
||||||
buf += id->buf_size;
|
buf += id->buf_size;
|
||||||
|
@ -934,8 +935,9 @@ debug_entry_t *debug_exception_common(debug_info_t *id, int level,
|
||||||
}
|
}
|
||||||
do {
|
do {
|
||||||
active = get_active_entry(id);
|
active = get_active_entry(id);
|
||||||
memset(DEBUG_DATA(active), 0, id->buf_size);
|
|
||||||
memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
|
memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
|
||||||
|
if (len < id->buf_size)
|
||||||
|
memset((DEBUG_DATA(active)) + len, 0, id->buf_size - len);
|
||||||
debug_finish_entry(id, active, level, len <= id->buf_size);
|
debug_finish_entry(id, active, level, len <= id->buf_size);
|
||||||
len -= id->buf_size;
|
len -= id->buf_size;
|
||||||
buf += id->buf_size;
|
buf += id->buf_size;
|
||||||
|
|
Loading…
Reference in New Issue