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/* -*- linux-c -*-
* Print Flush Function
* Copyright (C) 2007-2008 Red Hat Inc.
*
* This file is part of systemtap, and is free software. You can
* redistribute it and/or modify it under the terms of the GNU General
* Public License (GPL); either version 2, or (at your option) any
* later version.
*/
/** Send the print buffer to the transport now.
* Output accumulates in the print buffer until it
* is filled, or this is called. This MUST be called before returning
* from a probe or accumulated output in the print buffer will be lost.
*
* @note Preemption must be disabled to use this.
*/
static DEFINE_SPINLOCK(_stp_print_lock);
void EXPORT_FN(stp_print_flush) (_stp_pbuf *pb)
{
uint32_t len = pb->len;
/* check to see if there is anything in the buffer */
dbug_trans(1, "len = %ud\n", len);
if (likely (len == 0))
return;
pb->len = 0;
//DRS FIXME: this digs down too deep in internals
// if (unlikely(!_stp_utt || _stp_utt->trace_state != Utt_trace_running))
// return;
#ifdef STP_BULKMODE
{
#ifdef NO_PERCPU_HEADERS
void *buf = utt_reserve(_stp_utt, len);
if (likely(buf))
memcpy(buf, pb->buf, len);
else
atomic_inc (&_stp_transport_failures);
#else
void *buf = utt_reserve(_stp_utt,
sizeof(struct _stp_trace) + len);
if (likely(buf)) {
struct _stp_trace t = { .sequence = _stp_seq_inc(),
.pdu_len = len};
memcpy(buf, &t, sizeof(t)); // prevent unaligned access
memcpy(buf + sizeof(t), pb->buf, len);
} else
atomic_inc (&_stp_transport_failures);
#endif
}
#else
{
struct _stp_entry *entry;
unsigned long flags;
dbug_trans(1, "calling _stp_data_write...\n");
spin_lock_irqsave(&_stp_print_lock, flags);
#if 0
entry = _stp_data_write_reserve(len);
if (likely(entry)) {
memcpy(entry->buf, pb->buf, len);
_stp_data_write_commit(entry);
}
else
#endif
{
uint32_t cnt;
char *bufp = pb->buf;
#define MAX_RESERVE_SIZE (4080 /*BUF_PAGE_SIZE*/ - sizeof(struct _stp_entry) - 10)
while (len > 0) {
if (len > MAX_RESERVE_SIZE) {
len -= MAX_RESERVE_SIZE;
cnt = MAX_RESERVE_SIZE;
}
else {
cnt = len;
len = 0;
}
entry = _stp_data_write_reserve(cnt);
if (likely(entry)) {
memcpy(entry->buf, bufp, cnt);
_stp_data_write_commit(entry);
bufp += cnt;
}
else {
atomic_inc (&_stp_transport_failures);
break;
}
}
}
spin_unlock_irqrestore(&_stp_print_lock, flags);
}
#endif /* STP_BULKMODE */
}
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