[very-RFC 6/8] Add TSN event-tracing
From: Henrik Austad This needs refactoring and should be updated to use TRACE_CLASS, but for now it provides a fair debug-window into TSN. Cc: "David S. Miller" Cc: Steven Rostedt (maintainer:TRACING) Cc: Ingo Molnar (maintainer:TRACING) Signed-off-by: Henrik Austad --- include/trace/events/tsn.h | 349 + 1 file changed, 349 insertions(+) create mode 100644 include/trace/events/tsn.h diff --git a/include/trace/events/tsn.h b/include/trace/events/tsn.h new file mode 100644 index 000..ac1f31b --- /dev/null +++ b/include/trace/events/tsn.h @@ -0,0 +1,349 @@ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM tsn + +#if !defined(_TRACE_TSN_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_TSN_H + +#include +#include + +#include +#include +/* #include */ + +/* FIXME: update to TRACE_CLASS to reduce overhead */ +TRACE_EVENT(tsn_buffer_write, + + TP_PROTO(struct tsn_link *link, + size_t bytes), + + TP_ARGS(link, bytes), + + TP_STRUCT__entry( + __field(u64, stream_id) + __field(size_t, size) + __field(size_t, bsize) + __field(size_t, size_left) + __field(void *, buffer) + __field(void *, head) + __field(void *, tail) + __field(void *, end) + ), + + TP_fast_assign( + __entry->stream_id = link->stream_id; + __entry->size = bytes; + __entry->bsize = link->used_buffer_size; + __entry->size_left = (link->head - link->tail) % link->used_buffer_size; + __entry->buffer = link->buffer; + __entry->head = link->head; + __entry->tail = link->tail; + __entry->end = link->end; + ), + + TP_printk("stream_id=%llu, copy=%zd, buffer: %zd, avail=%zd, [buffer=%p, head=%p, tail=%p, end=%p]", + __entry->stream_id, __entry->size, __entry->bsize, __entry->size_left, + __entry->buffer,__entry->head, __entry->tail, __entry->end) + + ); + +TRACE_EVENT(tsn_buffer_write_net, + + TP_PROTO(struct tsn_link *link, + size_t bytes), + + TP_ARGS(link, bytes), + + TP_STRUCT__entry( + __field(u64, stream_id) + __field(size_t, size) + __field(size_t, bsize) + __field(size_t, size_left) + __field(void *, buffer) + __field(void *, head) + __field(void *, tail) + __field(void *, end) + ), + + TP_fast_assign( + __entry->stream_id = link->stream_id; + __entry->size = bytes; + __entry->bsize = link->used_buffer_size; + __entry->size_left = (link->head - link->tail) % link->used_buffer_size; + __entry->buffer = link->buffer; + __entry->head = link->head; + __entry->tail = link->tail; + __entry->end = link->end; + ), + + TP_printk("stream_id=%llu, copy=%zd, buffer: %zd, avail=%zd, [buffer=%p, head=%p, tail=%p, end=%p]", + __entry->stream_id, __entry->size, __entry->bsize, __entry->size_left, + __entry->buffer,__entry->head, __entry->tail, __entry->end) + + ); + + +TRACE_EVENT(tsn_buffer_read, + + TP_PROTO(struct tsn_link *link, + size_t bytes), + + TP_ARGS(link, bytes), + + TP_STRUCT__entry( + __field(u64, stream_id) + __field(size_t, size) + __field(size_t, bsize) + __field(size_t, size_left) + __field(void *, buffer) + __field(void *, head) + __field(void *, tail) + __field(void *, end) + ), + + TP_fast_assign( + __entry->stream_id = link->stream_id; + __entry->size = bytes; + __entry->bsize = link->used_buffer_size; + __entry->size_left = (link->head - link->tail) % link->used_buffer_size; + __entry->buffer = link->buffer; + __entry->head = link->head; + __entry->tail = link->tail; + __entry->end = link->end; + ), + + TP_printk("stream_id=%llu, copy=%zd, buffer: %zd, avail=%zd, [buffer=%p, head=%p, tail=%p, end=%p]", + __entry->stream_id, __entry->size, __entry->bsize, __entry->size_left, + __entry->buffer,__entry->head, __entry->tail, __entry->end) + + ); + +TRACE_EVENT(tsn_refill, + + TP_PROTO(struct tsn_link *link, + size_t reported_avail), + + TP_ARGS(link, reported_avail), + + TP_STRUCT__entry( + __field(u64, stream_id) + __field(size_t, bsize) + __field(size_t, size_left) + __field(size_t, reported_left) +
[very-RFC 6/8] Add TSN event-tracing
From: Henrik Austad This needs refactoring and should be updated to use TRACE_CLASS, but for now it provides a fair debug-window into TSN. Cc: "David S. Miller" Cc: Steven Rostedt (maintainer:TRACING) Cc: Ingo Molnar (maintainer:TRACING) Signed-off-by: Henrik Austad --- include/trace/events/tsn.h | 349 + 1 file changed, 349 insertions(+) create mode 100644 include/trace/events/tsn.h diff --git a/include/trace/events/tsn.h b/include/trace/events/tsn.h new file mode 100644 index 000..ac1f31b --- /dev/null +++ b/include/trace/events/tsn.h @@ -0,0 +1,349 @@ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM tsn + +#if !defined(_TRACE_TSN_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_TSN_H + +#include +#include + +#include +#include +/* #include */ + +/* FIXME: update to TRACE_CLASS to reduce overhead */ +TRACE_EVENT(tsn_buffer_write, + + TP_PROTO(struct tsn_link *link, + size_t bytes), + + TP_ARGS(link, bytes), + + TP_STRUCT__entry( + __field(u64, stream_id) + __field(size_t, size) + __field(size_t, bsize) + __field(size_t, size_left) + __field(void *, buffer) + __field(void *, head) + __field(void *, tail) + __field(void *, end) + ), + + TP_fast_assign( + __entry->stream_id = link->stream_id; + __entry->size = bytes; + __entry->bsize = link->used_buffer_size; + __entry->size_left = (link->head - link->tail) % link->used_buffer_size; + __entry->buffer = link->buffer; + __entry->head = link->head; + __entry->tail = link->tail; + __entry->end = link->end; + ), + + TP_printk("stream_id=%llu, copy=%zd, buffer: %zd, avail=%zd, [buffer=%p, head=%p, tail=%p, end=%p]", + __entry->stream_id, __entry->size, __entry->bsize, __entry->size_left, + __entry->buffer,__entry->head, __entry->tail, __entry->end) + + ); + +TRACE_EVENT(tsn_buffer_write_net, + + TP_PROTO(struct tsn_link *link, + size_t bytes), + + TP_ARGS(link, bytes), + + TP_STRUCT__entry( + __field(u64, stream_id) + __field(size_t, size) + __field(size_t, bsize) + __field(size_t, size_left) + __field(void *, buffer) + __field(void *, head) + __field(void *, tail) + __field(void *, end) + ), + + TP_fast_assign( + __entry->stream_id = link->stream_id; + __entry->size = bytes; + __entry->bsize = link->used_buffer_size; + __entry->size_left = (link->head - link->tail) % link->used_buffer_size; + __entry->buffer = link->buffer; + __entry->head = link->head; + __entry->tail = link->tail; + __entry->end = link->end; + ), + + TP_printk("stream_id=%llu, copy=%zd, buffer: %zd, avail=%zd, [buffer=%p, head=%p, tail=%p, end=%p]", + __entry->stream_id, __entry->size, __entry->bsize, __entry->size_left, + __entry->buffer,__entry->head, __entry->tail, __entry->end) + + ); + + +TRACE_EVENT(tsn_buffer_read, + + TP_PROTO(struct tsn_link *link, + size_t bytes), + + TP_ARGS(link, bytes), + + TP_STRUCT__entry( + __field(u64, stream_id) + __field(size_t, size) + __field(size_t, bsize) + __field(size_t, size_left) + __field(void *, buffer) + __field(void *, head) + __field(void *, tail) + __field(void *, end) + ), + + TP_fast_assign( + __entry->stream_id = link->stream_id; + __entry->size = bytes; + __entry->bsize = link->used_buffer_size; + __entry->size_left = (link->head - link->tail) % link->used_buffer_size; + __entry->buffer = link->buffer; + __entry->head = link->head; + __entry->tail = link->tail; + __entry->end = link->end; + ), + + TP_printk("stream_id=%llu, copy=%zd, buffer: %zd, avail=%zd, [buffer=%p, head=%p, tail=%p, end=%p]", + __entry->stream_id, __entry->size, __entry->bsize, __entry->size_left, + __entry->buffer,__entry->head, __entry->tail, __entry->end) + + ); + +TRACE_EVENT(tsn_refill, + + TP_PROTO(struct tsn_link *link, + size_t reported_avail), + + TP_ARGS(link, reported_avail), + + TP_STRUCT__entry( + __field(u64, stream_id) + __field(size_t, bsize) + __field(size_t, size_left) + __field(size_t, reported_left) +
Re: [very-RFC 6/8] Add TSN event-tracing
On Sun, 12 Jun 2016 01:01:34 +0200 Henrik Austad wrote: > From: Henrik Austad > > This needs refactoring and should be updated to use TRACE_CLASS, but for > now it provides a fair debug-window into TSN. > > Cc: "David S. Miller" > Cc: Steven Rostedt (maintainer:TRACING) > Cc: Ingo Molnar (maintainer:TRACING) > Signed-off-by: Henrik Austad > --- > include/trace/events/tsn.h | 349 > + > 1 file changed, 349 insertions(+) > create mode 100644 include/trace/events/tsn.h > > diff --git a/include/trace/events/tsn.h b/include/trace/events/tsn.h > new file mode 100644 > index 000..ac1f31b > --- /dev/null > +++ b/include/trace/events/tsn.h > @@ -0,0 +1,349 @@ > +#undef TRACE_SYSTEM > +#define TRACE_SYSTEM tsn > + > +#if !defined(_TRACE_TSN_H) || defined(TRACE_HEADER_MULTI_READ) > +#define _TRACE_TSN_H > + > +#include > +#include > + > +#include > +#include > +/* #include */ > + > +/* FIXME: update to TRACE_CLASS to reduce overhead */ I'm curious to why I didn't do this now. A class would make less duplication of typing too ;-) > +TRACE_EVENT(tsn_buffer_write, > + > + TP_PROTO(struct tsn_link *link, > + size_t bytes), > + > + TP_ARGS(link, bytes), > + > + TP_STRUCT__entry( > + __field(u64, stream_id) > + __field(size_t, size) > + __field(size_t, bsize) > + __field(size_t, size_left) > + __field(void *, buffer) > + __field(void *, head) > + __field(void *, tail) > + __field(void *, end) > + ), > + > + TP_fast_assign( > + __entry->stream_id = link->stream_id; > + __entry->size = bytes; > + __entry->bsize = link->used_buffer_size; > + __entry->size_left = (link->head - link->tail) % > link->used_buffer_size; Move this logic into the print statement, since you save head and tail. > + __entry->buffer = link->buffer; > + __entry->head = link->head; > + __entry->tail = link->tail; > + __entry->end = link->end; > + ), > + > + TP_printk("stream_id=%llu, copy=%zd, buffer: %zd, avail=%zd, > [buffer=%p, head=%p, tail=%p, end=%p]", > + __entry->stream_id, __entry->size, __entry->bsize, > __entry->size_left, __entry->stream_id, __entry->size, __entry->bsize, (__entry->head - __entry->tail) % __entry->bsize, > + __entry->buffer,__entry->head, __entry->tail, __entry->end) > + > + ); > + > +TRACE_EVENT(tsn_buffer_write_net, > + > + TP_PROTO(struct tsn_link *link, > + size_t bytes), > + > + TP_ARGS(link, bytes), > + > + TP_STRUCT__entry( > + __field(u64, stream_id) > + __field(size_t, size) > + __field(size_t, bsize) > + __field(size_t, size_left) > + __field(void *, buffer) > + __field(void *, head) > + __field(void *, tail) > + __field(void *, end) > + ), > + > + TP_fast_assign( > + __entry->stream_id = link->stream_id; > + __entry->size = bytes; > + __entry->bsize = link->used_buffer_size; > + __entry->size_left = (link->head - link->tail) % > link->used_buffer_size; > + __entry->buffer = link->buffer; > + __entry->head = link->head; > + __entry->tail = link->tail; > + __entry->end = link->end; > + ), > + > + TP_printk("stream_id=%llu, copy=%zd, buffer: %zd, avail=%zd, > [buffer=%p, head=%p, tail=%p, end=%p]", > + __entry->stream_id, __entry->size, __entry->bsize, > __entry->size_left, > + __entry->buffer,__entry->head, __entry->tail, __entry->end) > + > + ); > + > + > +TRACE_EVENT(tsn_buffer_read, > + > + TP_PROTO(struct tsn_link *link, > + size_t bytes), > + > + TP_ARGS(link, bytes), > + > + TP_STRUCT__entry( > + __field(u64, stream_id) > + __field(size_t, size) > + __field(size_t, bsize) > + __field(size_t, size_left) > + __field(void *, buffer) > + __field(void *, head) > + __field(void *, tail) > + __field(void *, end) > + ), > + > + TP_fast_assign( > + __entry->stream_id = link->stream_id; > + __entry->size = bytes; > + __entry->bsize = link->used_buffer_size; > + __entry->size_left = (link->head - link->tail) % > link->used_buffer_size; > + __entry->buffer = link->buffer; > + __entry->head = link->head; > + __entry->tail = link->tail; > + __entry->end = link->end; > + ), > + > + TP_printk("stream_id=%llu, copy=%zd, buffer: %zd, avail=%zd, > [buffer=%p, head=%p, tail=%p, end=%p]", > + __entry->stream_id, __entry->size, __entry->bsize, >
Re: [very-RFC 6/8] Add TSN event-tracing
On Sun, Jun 12, 2016 at 12:58:03PM -0400, Steven Rostedt wrote: > On Sun, 12 Jun 2016 01:01:34 +0200 > Henrik Austad wrote: > > > From: Henrik Austad > > > > This needs refactoring and should be updated to use TRACE_CLASS, but for > > now it provides a fair debug-window into TSN. > > > > Cc: "David S. Miller" > > Cc: Steven Rostedt (maintainer:TRACING) > > Cc: Ingo Molnar (maintainer:TRACING) > > Signed-off-by: Henrik Austad > > --- > > include/trace/events/tsn.h | 349 > > + > > 1 file changed, 349 insertions(+) > > create mode 100644 include/trace/events/tsn.h > > > > diff --git a/include/trace/events/tsn.h b/include/trace/events/tsn.h > > new file mode 100644 > > index 000..ac1f31b > > --- /dev/null > > +++ b/include/trace/events/tsn.h > > @@ -0,0 +1,349 @@ > > +#undef TRACE_SYSTEM > > +#define TRACE_SYSTEM tsn > > + > > +#if !defined(_TRACE_TSN_H) || defined(TRACE_HEADER_MULTI_READ) > > +#define _TRACE_TSN_H > > + > > +#include > > +#include > > + > > +#include > > +#include > > +/* #include */ > > + > > +/* FIXME: update to TRACE_CLASS to reduce overhead */ > > I'm curious to why I didn't do this now. A class would make less > duplication of typing too ;-) Yeah, I found this in a really great article written by some tracing-dude, I hear he talks really, really fast! https://lwn.net/Articles/381064/ > > +TRACE_EVENT(tsn_buffer_write, > > + > > + TP_PROTO(struct tsn_link *link, > > + size_t bytes), > > + > > + TP_ARGS(link, bytes), > > + > > + TP_STRUCT__entry( > > + __field(u64, stream_id) > > + __field(size_t, size) > > + __field(size_t, bsize) > > + __field(size_t, size_left) > > + __field(void *, buffer) > > + __field(void *, head) > > + __field(void *, tail) > > + __field(void *, end) > > + ), > > + > > + TP_fast_assign( > > + __entry->stream_id = link->stream_id; > > + __entry->size = bytes; > > + __entry->bsize = link->used_buffer_size; > > + __entry->size_left = (link->head - link->tail) % > > link->used_buffer_size; > > Move this logic into the print statement, since you save head and tail. Ok, any particular reason? > > + __entry->buffer = link->buffer; > > + __entry->head = link->head; > > + __entry->tail = link->tail; > > + __entry->end = link->end; > > + ), > > + > > + TP_printk("stream_id=%llu, copy=%zd, buffer: %zd, avail=%zd, > > [buffer=%p, head=%p, tail=%p, end=%p]", > > + __entry->stream_id, __entry->size, __entry->bsize, > > __entry->size_left, > > __entry->stream_id, __entry->size, __entry->bsize, > (__entry->head - __entry->tail) % __entry->bsize, > Ok, so is this about saving space by dropping one intermediate value, or is it some other point I'm missing here? > > + __entry->buffer,__entry->head, __entry->tail, __entry->end) > > + > > + ); > > + > > +TRACE_EVENT(tsn_buffer_write_net, > > + > > + TP_PROTO(struct tsn_link *link, > > + size_t bytes), > > + > > + TP_ARGS(link, bytes), > > + > > + TP_STRUCT__entry( > > + __field(u64, stream_id) > > + __field(size_t, size) > > + __field(size_t, bsize) > > + __field(size_t, size_left) > > + __field(void *, buffer) > > + __field(void *, head) > > + __field(void *, tail) > > + __field(void *, end) > > + ), > > + > > + TP_fast_assign( > > + __entry->stream_id = link->stream_id; > > + __entry->size = bytes; > > + __entry->bsize = link->used_buffer_size; > > + __entry->size_left = (link->head - link->tail) % > > link->used_buffer_size; > > + __entry->buffer = link->buffer; > > + __entry->head = link->head; > > + __entry->tail = link->tail; > > + __entry->end = link->end; > > + ), > > + > > + TP_printk("stream_id=%llu, copy=%zd, buffer: %zd, avail=%zd, > > [buffer=%p, head=%p, tail=%p, end=%p]", > > + __entry->stream_id, __entry->size, __entry->bsize, > > __entry->size_left, > > + __entry->buffer,__entry->head, __entry->tail, __entry->end) > > + > > + ); > > + > > + > > +TRACE_EVENT(tsn_buffer_read, > > + > > + TP_PROTO(struct tsn_link *link, > > + size_t bytes), > > + > > + TP_ARGS(link, bytes), > > + > > + TP_STRUCT__entry( > > + __field(u64, stream_id) > > + __field(size_t, size) > > + __field(size_t, bsize) > > + __field(size_t, size_left) > > + __field(void *, buffer) > > + __field(void *, head) > > + __field(void *, tail) > > + __field(void *, end) > > + ), > > + > > + TP_fast_assign( > > + __entry->stream_id = link->stream_id; > > + __entry->size = bytes; > > + __entry->
Re: [very-RFC 6/8] Add TSN event-tracing
On Sun, 12 Jun 2016 23:25:10 +0200 Henrik Austad wrote: > > > +#include > > > +#include > > > +/* #include */ > > > + > > > +/* FIXME: update to TRACE_CLASS to reduce overhead */ > > > > I'm curious to why I didn't do this now. A class would make less > > duplication of typing too ;-) > > Yeah, I found this in a really great article written by some tracing-dude, > I hear he talks really, really fast! I plead the 5th! > > https://lwn.net/Articles/381064/ > > > > +TRACE_EVENT(tsn_buffer_write, > > > + > > > + TP_PROTO(struct tsn_link *link, > > > + size_t bytes), > > > + > > > + TP_ARGS(link, bytes), > > > + > > > + TP_STRUCT__entry( > > > + __field(u64, stream_id) > > > + __field(size_t, size) > > > + __field(size_t, bsize) > > > + __field(size_t, size_left) > > > + __field(void *, buffer) > > > + __field(void *, head) > > > + __field(void *, tail) > > > + __field(void *, end) > > > + ), > > > + > > > + TP_fast_assign( > > > + __entry->stream_id = link->stream_id; > > > + __entry->size = bytes; > > > + __entry->bsize = link->used_buffer_size; > > > + __entry->size_left = (link->head - link->tail) % > > > link->used_buffer_size; > > > > Move this logic into the print statement, since you save head and tail. > > Ok, any particular reason? Because it removes calculations during the trace. The calculations done in TP_printk() are done at the time of reading the trace, and calculations done in TP_fast_assign() are done during the recording and hence adding more overhead to the trace itself. > > > > + __entry->buffer = link->buffer; > > > + __entry->head = link->head; > > > + __entry->tail = link->tail; > > > + __entry->end = link->end; > > > + ), > > > + > > > + TP_printk("stream_id=%llu, copy=%zd, buffer: %zd, avail=%zd, > > > [buffer=%p, head=%p, tail=%p, end=%p]", > > > + __entry->stream_id, __entry->size, __entry->bsize, > > > __entry->size_left, > > > > __entry->stream_id, __entry->size, __entry->bsize, > > (__entry->head - __entry->tail) % __entry->bsize, > > > > Ok, so is this about saving space by dropping one intermediate value, or is > it some other point I'm missing here? Nope, just moving the overhead from the recording of the trace to the reading of the trace. > > > > + __entry->buffer,__entry->head, __entry->tail, __entry->end) > > > + > > > + ); > > > + > > > + > > > + TP_fast_assign( > > > + __entry->stream_id = link->stream_id; > > > + __entry->vlan_tag = (skb_vlan_tag_present(skb) ? > > > skb_vlan_tag_get(skb) : 0); > > > + __entry->bytes = bytes; > > > + __entry->data_len = skb->data_len; > > > + __entry->headlen = skb_headlen(skb); > > > + __entry->protocol = ntohs(vlan_get_protocol(skb)); > > > > Maybe it would be better to do the ntohs() in the TP_printk() as well. > > > > > + __entry->prot_native = ntohs(skb->protocol); > > > > here too. > > > > > + __entry->tx_idx = skb_get_queue_mapping(skb); > > > + > > > + __entry->mac_len = skb->mac_len; > > > + __entry->hdr_len = skb->hdr_len; > > > + __entry->vlan_tci = skb->vlan_tci; > > > + __entry->mac_header = skb->mac_header; > > > + __entry->tail = (unsigned int)skb->tail; > > > + __entry->end = (unsigned int)skb->end; > > > + __entry->truesize = skb->truesize; > > > + ), > > > + > > > + > > > TP_printk("stream_id=%llu,vlan_tag=0x%04x,data_size=%zd,data_len=%zd,headlen=%u,proto=0x%04x > > > > > > (0x%04x),tx_idx=%d,mac_len=%u,hdr_len=%u,vlan_tci=0x%02x,mac_header=0x%02x,tail=%u,end=%u,truesize=%u", > > > + __entry->stream_id, > > > + __entry->vlan_tag, > > > + __entry->bytes, > > > + __entry->data_len, > > > + __entry->headlen, > > > + __entry->protocol, > > > + __entry->prot_native, __entry->tx_idx, > > > + __entry->mac_len, > > > + __entry->hdr_len, > > > + __entry->vlan_tci, > > > + __entry->mac_header, > > > > Is this an ether mac header? If so we support %M. But as it's defined > > as only u16, it doesn't seem like it can be. > > Actually, looking at the output, I'm not quite sure what it is that I > wanted to grab with that, the skb->mac_header should give an offset into > the header-area of skb, so it should be a constant offset from skb->head > (that is an actual pointer). > > I *think* I wanted to make sure I updated things correctly so that the > offset didn't suddenly change, but the fact that I'm no longer sure > indicates that I should just drop that one. That whole printout is too long > anyway.. > > Thanks for pointing a finger at this! > > > I'm still a bit stymied as to why logic should be in TP_printk() and not > TP_fast_assign(). Not that I really have any preference
Re: [very-RFC 6/8] Add TSN event-tracing
On Sun, Jun 12, 2016 at 10:22:01PM -0400, Steven Rostedt wrote: > On Sun, 12 Jun 2016 23:25:10 +0200 > Henrik Austad wrote: > > > > > +#include > > > > +#include > > > > +/* #include */ > > > > + > > > > +/* FIXME: update to TRACE_CLASS to reduce overhead */ > > > > > > I'm curious to why I didn't do this now. A class would make less > > > duplication of typing too ;-) > > > > Yeah, I found this in a really great article written by some tracing-dude, > > I hear he talks really, really fast! > > I plead the 5th! > > > > > https://lwn.net/Articles/381064/ > > > > > > +TRACE_EVENT(tsn_buffer_write, > > > > + > > > > + TP_PROTO(struct tsn_link *link, > > > > + size_t bytes), > > > > + > > > > + TP_ARGS(link, bytes), > > > > + > > > > + TP_STRUCT__entry( > > > > + __field(u64, stream_id) > > > > + __field(size_t, size) > > > > + __field(size_t, bsize) > > > > + __field(size_t, size_left) > > > > + __field(void *, buffer) > > > > + __field(void *, head) > > > > + __field(void *, tail) > > > > + __field(void *, end) > > > > + ), > > > > + > > > > + TP_fast_assign( > > > > + __entry->stream_id = link->stream_id; > > > > + __entry->size = bytes; > > > > + __entry->bsize = link->used_buffer_size; > > > > + __entry->size_left = (link->head - link->tail) % > > > > link->used_buffer_size; > > > > > > Move this logic into the print statement, since you save head and tail. > > > > Ok, any particular reason? > > Because it removes calculations during the trace. The calculations done > in TP_printk() are done at the time of reading the trace, and > calculations done in TP_fast_assign() are done during the recording and > hence adding more overhead to the trace itself. Aha! that makes sense, thanks! (/me goes and updates the tracing-part) -Henrik signature.asc Description: Digital signature