Re: [RFC PATCH] trace event block: conversion to tp_assign/tp_memcpy

Jeff Moyer
2010-12-20T18:24:46Z

Mathieu Desnoyers <mathieu.desnoyers@efficios.com> writes:

> Given that there are calls from TP_fast_assign to functions sitting in
> blktrace.c, move all pretty-printing out of TP_fast_assign fast path, into
> TP_printk, by using __print_flags().

> Warning: the TP_printk ascii output does not change, but the raw binary output
> is modified. Comments/feedback are welcome. Are there userspace tools that
> depend on a fixed binary layout for the block events ?

Yes, the user-space blktrace utility consumes the binary data. I've
CC'd Alan Brunelle to comment further.

Cheers,
Jeff

> This patch is submitted as RFC and depends on a yet unposted version of the
> tp_assign/tp_memcpy patch that introduces "tp_memcpy_dyn", which allows to
> memcpy dynamic arrays. I'm posting this RFC now mainly to get feedback on tool
> dependency on a fixed trace binary layout for block layer events.
>
> Feedback is welcome,
>
> Thanks,
>
> Mathieu
>
> ---
> include/linux/blktrace_api.h | 13 --
> include/trace/events/block.h | 225 +++++++++++++++++++++++++++----------------
> kernel/trace/blktrace.c | 61 +----------
> 3 files changed, 156 insertions(+), 143 deletions(-)
>
> Index: linux-2.6-lttng/include/trace/events/block.h
> ===================================================================
> --- linux-2.6-lttng.orig/include/trace/events/block.h
> +++ linux-2.6-lttng/include/trace/events/block.h
> @@ -7,6 +7,60 @@
> #include <linux/blktrace_api.h>
> #include <linux/blkdev.h>
> #include <linux/tracepoint.h>
> +#include <linux/trace_seq.h>
> +
> +#ifndef _TRACE_BLOCK_DEF_
> +#define _TRACE_BLOCK_DEF_
> +
> +static inline int blk_cmd_buf_len(struct request *rq)
> +{
> + return (rq->cmd_type == REQ_TYPE_BLOCK_PC) ? rq->cmd_len : 0;
> +}
> +
> +const char *blk_dump_cmd(struct trace_seq *p, unsigned char *cmd, int len);
> +#define __blk_dump_cmd(cmd, len) blk_dump_cmd(p, cmd, len)
> +
> +enum {
> + RWBS_FLAG_WRITE = (1 << 0),
> + RWBS_FLAG_DISCARD = (1 << 1),
> + RWBS_FLAG_READ = (1 << 2),
> + RWBS_FLAG_RAHEAD = (1 << 3),
> + RWBS_FLAG_HARDBARRIER = (1 << 4),
> + RWBS_FLAG_SYNC = (1 << 5),
> + RWBS_FLAG_META = (1 << 6),
> + RWBS_FLAG_SECURE = (1 << 7),
> +};
> +
> +#endif /* _TRACE_BLOCK_DEF_ */
> +
> +#define __print_rwbs_flags(rwbs) \
> + __print_flags(rwbs, "", \
> + { RWBS_FLAG_WRITE, "W" }, \
> + { RWBS_FLAG_DISCARD, "D" }, \
> + { RWBS_FLAG_READ, "R" }, \
> + { RWBS_FLAG_RAHEAD, "A" }, \
> + { RWBS_FLAG_HARDBARRIER, "B" }, \
> + { RWBS_FLAG_SYNC, "S" }, \
> + { RWBS_FLAG_META, "M" }, \
> + { RWBS_FLAG_SECURE, "E" })
> +
> +#define blk_fill_rwbs_rq(rwbs, rq) \
> + tp_assign(rwbs, ((rq)->cmd_flags & WRITE ? RWBS_FLAG_WRITE : \
> + ((rq)->cmd_flags & REQ_DISCARD ? RWBS_FLAG_DISCARD : \
> + ( blk_rq_bytes(rq) ? RWBS_FLAG_READ : \
> + (0)))) \
> + | ((rq)->cmd_flags & REQ_SECURE ? RWBS_FLAG_SECURE : 0))
> +
> +#define blk_fill_rwbs(rwbs, rw, bytes) \
> + tp_assign(rwbs, ((rw) & WRITE ? RWBS_FLAG_WRITE : \
> + ( (rw) & REQ_DISCARD ? RWBS_FLAG_DISCARD : \
> + ( (bytes) ? RWBS_FLAG_READ : \
> + ( 0 )))) \
> + | ((rw) & REQ_RAHEAD ? RWBS_FLAG_RAHEAD : 0) \
> + | ((rw) & REQ_HARDBARRIER ? RWBS_FLAG_HARDBARRIER : 0)\
> + | ((rw) & REQ_SYNC ? RWBS_FLAG_SYNC : 0) \
> + | ((rw) & REQ_META ? RWBS_FLAG_META : 0) \
> + | ((rw) & REQ_SECURE ? RWBS_FLAG_SECURE : 0))
>
> DECLARE_EVENT_CLASS(block_rq_with_error,
>
> @@ -19,25 +73,26 @@ DECLARE_EVENT_CLASS(block_rq_with_error,
> __field( sector_t, sector )
> __field( unsigned int, nr_sector )
> __field( int, errors )
> - __array( char, rwbs, 6 )
> + __field( unsigned int, rwbs )
> __dynamic_array( char, cmd, blk_cmd_buf_len(rq) )
> ),
>
> TP_fast_assign(
> - __entry->dev = rq->rq_disk ? disk_devt(rq->rq_disk) : 0;
> - __entry->sector = (rq->cmd_type == REQ_TYPE_BLOCK_PC) ?
> - 0 : blk_rq_pos(rq);
> - __entry->nr_sector = (rq->cmd_type == REQ_TYPE_BLOCK_PC) ?
> - 0 : blk_rq_sectors(rq);
> - __entry->errors = rq->errors;
> -
> - blk_fill_rwbs_rq(__entry->rwbs, rq);
> - blk_dump_cmd(__get_str(cmd), rq);
> + tp_assign(dev, rq->rq_disk ? disk_devt(rq->rq_disk) : 0)
> + tp_assign(sector, (rq->cmd_type == REQ_TYPE_BLOCK_PC) ?
> + 0 : blk_rq_pos(rq))
> + tp_assign(nr_sector, (rq->cmd_type == REQ_TYPE_BLOCK_PC) ?
> + 0 : blk_rq_sectors(rq))
> + tp_assign(errors, rq->errors)
> + blk_fill_rwbs_rq(rwbs, rq)
> + tp_memcpy_dyn(cmd, rq->cmd, blk_cmd_buf_len(rq))
> ),
>
> TP_printk("%d,%d %s (%s) %llu + %u [%d]",
> MAJOR(__entry->dev), MINOR(__entry->dev),
> - __entry->rwbs, __get_str(cmd),
> + __print_rwbs_flags(__entry->rwbs),
> + __blk_dump_cmd(__get_dynamic_array(cmd),
> + __get_dynamic_array_len(cmd)),
> (unsigned long long)__entry->sector,
> __entry->nr_sector, __entry->errors)
> );
> @@ -104,28 +159,30 @@ DECLARE_EVENT_CLASS(block_rq,
> __field( sector_t, sector )
> __field( unsigned int, nr_sector )
> __field( unsigned int, bytes )
> - __array( char, rwbs, 6 )
> + __field( unsigned int, rwbs )
> __array( char, comm, TASK_COMM_LEN )
> __dynamic_array( char, cmd, blk_cmd_buf_len(rq) )
> ),
>
> TP_fast_assign(
> - __entry->dev = rq->rq_disk ? disk_devt(rq->rq_disk) : 0;
> - __entry->sector = (rq->cmd_type == REQ_TYPE_BLOCK_PC) ?
> - 0 : blk_rq_pos(rq);
> - __entry->nr_sector = (rq->cmd_type == REQ_TYPE_BLOCK_PC) ?
> - 0 : blk_rq_sectors(rq);
> - __entry->bytes = (rq->cmd_type == REQ_TYPE_BLOCK_PC) ?
> - blk_rq_bytes(rq) : 0;
> -
> - blk_fill_rwbs_rq(__entry->rwbs, rq);
> - blk_dump_cmd(__get_str(cmd), rq);
> - memcpy(__entry->comm, current->comm, TASK_COMM_LEN);
> + tp_assign(dev, rq->rq_disk ? disk_devt(rq->rq_disk) : 0)
> + tp_assign(sector, (rq->cmd_type == REQ_TYPE_BLOCK_PC) ?
> + 0 : blk_rq_pos(rq))
> + tp_assign(nr_sector, (rq->cmd_type == REQ_TYPE_BLOCK_PC) ?
> + 0 : blk_rq_sectors(rq))
> + tp_assign(bytes, (rq->cmd_type == REQ_TYPE_BLOCK_PC) ?
> + blk_rq_bytes(rq) : 0)
> + blk_fill_rwbs_rq(rwbs, rq)
> + tp_memcpy_dyn(cmd, rq->cmd, blk_cmd_buf_len(rq))
> + tp_memcpy(comm, current->comm, TASK_COMM_LEN)
> ),
>
> TP_printk("%d,%d %s %u (%s) %llu + %u [%s]",
> MAJOR(__entry->dev), MINOR(__entry->dev),
> - __entry->rwbs, __entry->bytes, __get_str(cmd),
> + __print_rwbs_flags(__entry->rwbs),
> + __entry->bytes,
> + __blk_dump_cmd(__get_dynamic_array(cmd),
> + __get_dynamic_array_len(cmd)),
> (unsigned long long)__entry->sector,
> __entry->nr_sector, __entry->comm)
> );
> @@ -183,21 +240,22 @@ TRACE_EVENT(block_bio_bounce,
> __field( dev_t, dev )
> __field( sector_t, sector )
> __field( unsigned int, nr_sector )
> - __array( char, rwbs, 6 )
> + __field( unsigned int, rwbs )
> __array( char, comm, TASK_COMM_LEN )
> ),
>
> TP_fast_assign(
> - __entry->dev = bio->bi_bdev ?
> - bio->bi_bdev->bd_dev : 0;
> - __entry->sector = bio->bi_sector;
> - __entry->nr_sector = bio->bi_size >> 9;
> - blk_fill_rwbs(__entry->rwbs, bio->bi_rw, bio->bi_size);
> - memcpy(__entry->comm, current->comm, TASK_COMM_LEN);
> + tp_assign(dev, bio->bi_bdev ?
> + bio->bi_bdev->bd_dev : 0)
> + tp_assign(sector, bio->bi_sector)
> + tp_assign(nr_sector, bio->bi_size >> 9)
> + blk_fill_rwbs(rwbs, bio->bi_rw, bio->bi_size)
> + tp_memcpy(comm, current->comm, TASK_COMM_LEN)
> ),
>
> TP_printk("%d,%d %s %llu + %u [%s]",
> - MAJOR(__entry->dev), MINOR(__entry->dev), __entry->rwbs,
> + MAJOR(__entry->dev), MINOR(__entry->dev),
> + __print_rwbs_flags(__entry->rwbs),
> (unsigned long long)__entry->sector,
> __entry->nr_sector, __entry->comm)
> );
> @@ -221,18 +279,19 @@ TRACE_EVENT(block_bio_complete,
> __field( sector_t, sector )
> __field( unsigned, nr_sector )
> __field( int, error )
> - __array( char, rwbs, 6 )
> + __field( unsigned int, rwbs )
> ),
>
> TP_fast_assign(
> - __entry->dev = bio->bi_bdev->bd_dev;
> - __entry->sector = bio->bi_sector;
> - __entry->nr_sector = bio->bi_size >> 9;
> - blk_fill_rwbs(__entry->rwbs, bio->bi_rw, bio->bi_size);
> + tp_assign(dev, bio->bi_bdev->bd_dev)
> + tp_assign(sector, bio->bi_sector)
> + tp_assign(nr_sector, bio->bi_size >> 9)
> + blk_fill_rwbs(rwbs, bio->bi_rw, bio->bi_size)
> ),
>
> TP_printk("%d,%d %s %llu + %u [%d]",
> - MAJOR(__entry->dev), MINOR(__entry->dev), __entry->rwbs,
> + MAJOR(__entry->dev), MINOR(__entry->dev),
> + __print_rwbs_flags(__entry->rwbs),
> (unsigned long long)__entry->sector,
> __entry->nr_sector, __entry->error)
> );
> @@ -247,20 +306,21 @@ DECLARE_EVENT_CLASS(block_bio,
> __field( dev_t, dev )
> __field( sector_t, sector )
> __field( unsigned int, nr_sector )
> - __array( char, rwbs, 6 )
> + __field( unsigned int, rwbs )
> __array( char, comm, TASK_COMM_LEN )
> ),
>
> TP_fast_assign(
> - __entry->dev = bio->bi_bdev->bd_dev;
> - __entry->sector = bio->bi_sector;
> - __entry->nr_sector = bio->bi_size >> 9;
> - blk_fill_rwbs(__entry->rwbs, bio->bi_rw, bio->bi_size);
> - memcpy(__entry->comm, current->comm, TASK_COMM_LEN);
> + tp_assign(dev, bio->bi_bdev->bd_dev)
> + tp_assign(sector, bio->bi_sector)
> + tp_assign(nr_sector, bio->bi_size >> 9)
> + blk_fill_rwbs(rwbs, bio->bi_rw, bio->bi_size)
> + tp_memcpy(comm, current->comm, TASK_COMM_LEN)
> ),
>
> TP_printk("%d,%d %s %llu + %u [%s]",
> - MAJOR(__entry->dev), MINOR(__entry->dev), __entry->rwbs,
> + MAJOR(__entry->dev), MINOR(__entry->dev),
> + __print_rwbs_flags(__entry->rwbs),
> (unsigned long long)__entry->sector,
> __entry->nr_sector, __entry->comm)
> );
> @@ -319,21 +379,21 @@ DECLARE_EVENT_CLASS(block_get_rq,
> __field( dev_t, dev )
> __field( sector_t, sector )
> __field( unsigned int, nr_sector )
> - __array( char, rwbs, 6 )
> + __field( unsigned int, rwbs )
> __array( char, comm, TASK_COMM_LEN )
> ),
>
> TP_fast_assign(
> - __entry->dev = bio ? bio->bi_bdev->bd_dev : 0;
> - __entry->sector = bio ? bio->bi_sector : 0;
> - __entry->nr_sector = bio ? bio->bi_size >> 9 : 0;
> - blk_fill_rwbs(__entry->rwbs,
> - bio ? bio->bi_rw : 0, __entry->nr_sector);
> - memcpy(__entry->comm, current->comm, TASK_COMM_LEN);
> + tp_assign(dev, bio ? bio->bi_bdev->bd_dev : 0)
> + tp_assign(sector, bio ? bio->bi_sector : 0)
> + tp_assign(nr_sector, bio ? bio->bi_size >> 9 : 0)
> + blk_fill_rwbs(rwbs, bio ? bio->bi_rw : 0, __entry->nr_sector)
> + tp_memcpy(comm, current->comm, TASK_COMM_LEN)
> ),
>
> TP_printk("%d,%d %s %llu + %u [%s]",
> - MAJOR(__entry->dev), MINOR(__entry->dev), __entry->rwbs,
> + MAJOR(__entry->dev), MINOR(__entry->dev),
> + __print_rwbs_flags(__entry->rwbs),
> (unsigned long long)__entry->sector,
> __entry->nr_sector, __entry->comm)
> );
> @@ -391,7 +451,7 @@ TRACE_EVENT(block_plug,
> ),
>
> TP_fast_assign(
> - memcpy(__entry->comm, current->comm, TASK_COMM_LEN);
> + tp_memcpy(comm, current->comm, TASK_COMM_LEN)
> ),
>
> TP_printk("[%s]", __entry->comm)
> @@ -409,8 +469,8 @@ DECLARE_EVENT_CLASS(block_unplug,
> ),
>
> TP_fast_assign(
> - __entry->nr_rq = q->rq.count[READ] + q->rq.count[WRITE];
> - memcpy(__entry->comm, current->comm, TASK_COMM_LEN);
> + tp_assign(nr_rq, q->rq.count[READ] + q->rq.count[WRITE])
> + tp_memcpy(comm, current->comm, TASK_COMM_LEN)
> ),
>
> TP_printk("[%s] %d", __entry->comm, __entry->nr_rq)
> @@ -466,20 +526,21 @@ TRACE_EVENT(block_split,
> __field( dev_t, dev )
> __field( sector_t, sector )
> __field( sector_t, new_sector )
> - __array( char, rwbs, 6 )
> + __field( unsigned int, rwbs )
> __array( char, comm, TASK_COMM_LEN )
> ),
>
> TP_fast_assign(
> - __entry->dev = bio->bi_bdev->bd_dev;
> - __entry->sector = bio->bi_sector;
> - __entry->new_sector = new_sector;
> - blk_fill_rwbs(__entry->rwbs, bio->bi_rw, bio->bi_size);
> - memcpy(__entry->comm, current->comm, TASK_COMM_LEN);
> + tp_assign(dev, bio->bi_bdev->bd_dev)
> + tp_assign(sector, bio->bi_sector)
> + tp_assign(new_sector, new_sector)
> + blk_fill_rwbs(rwbs, bio->bi_rw, bio->bi_size)
> + tp_memcpy(comm, current->comm, TASK_COMM_LEN)
> ),
>
> TP_printk("%d,%d %s %llu / %llu [%s]",
> - MAJOR(__entry->dev), MINOR(__entry->dev), __entry->rwbs,
> + MAJOR(__entry->dev), MINOR(__entry->dev),
> + __print_rwbs_flags(__entry->rwbs),
> (unsigned long long)__entry->sector,
> (unsigned long long)__entry->new_sector,
> __entry->comm)
> @@ -508,20 +569,21 @@ TRACE_EVENT(block_remap,
> __field( unsigned int, nr_sector )
> __field( dev_t, old_dev )
> __field( sector_t, old_sector )
> - __array( char, rwbs, 6 )
> + __field( unsigned int, rwbs )
> ),
>
> TP_fast_assign(
> - __entry->dev = bio->bi_bdev->bd_dev;
> - __entry->sector = bio->bi_sector;
> - __entry->nr_sector = bio->bi_size >> 9;
> - __entry->old_dev = dev;
> - __entry->old_sector = from;
> - blk_fill_rwbs(__entry->rwbs, bio->bi_rw, bio->bi_size);
> + tp_assign(dev, bio->bi_bdev->bd_dev)
> + tp_assign(sector, bio->bi_sector)
> + tp_assign(nr_sector, bio->bi_size >> 9)
> + tp_assign(old_dev, dev)
> + tp_assign(old_sector, from)
> + blk_fill_rwbs(rwbs, bio->bi_rw, bio->bi_size)
> ),
>
> TP_printk("%d,%d %s %llu + %u <- (%d,%d) %llu",
> - MAJOR(__entry->dev), MINOR(__entry->dev), __entry->rwbs,
> + MAJOR(__entry->dev), MINOR(__entry->dev),
> + __print_rwbs_flags(__entry->rwbs),
> (unsigned long long)__entry->sector,
> __entry->nr_sector,
> MAJOR(__entry->old_dev), MINOR(__entry->old_dev),
> @@ -552,26 +614,31 @@ TRACE_EVENT(block_rq_remap,
> __field( unsigned int, nr_sector )
> __field( dev_t, old_dev )
> __field( sector_t, old_sector )
> - __array( char, rwbs, 6 )
> + __field( unsigned int, rwbs )
> ),
>
> TP_fast_assign(
> - __entry->dev = disk_devt(rq->rq_disk);
> - __entry->sector = blk_rq_pos(rq);
> - __entry->nr_sector = blk_rq_sectors(rq);
> - __entry->old_dev = dev;
> - __entry->old_sector = from;
> - blk_fill_rwbs_rq(__entry->rwbs, rq);
> + tp_assign(dev, disk_devt(rq->rq_disk))
> + tp_assign(sector, blk_rq_pos(rq))
> + tp_assign(nr_sector, blk_rq_sectors(rq))
> + tp_assign(old_dev, dev)
> + tp_assign(old_sector, from)
> + blk_fill_rwbs_rq(rwbs, rq)
> ),
>
> TP_printk("%d,%d %s %llu + %u <- (%d,%d) %llu",
> - MAJOR(__entry->dev), MINOR(__entry->dev), __entry->rwbs,
> + MAJOR(__entry->dev), MINOR(__entry->dev),
> + __print_rwbs_flags(__entry->rwbs),
> (unsigned long long)__entry->sector,
> __entry->nr_sector,
> MAJOR(__entry->old_dev), MINOR(__entry->old_dev),
> (unsigned long long)__entry->old_sector)
> );
>
> +#undef __print_rwbs_flags
> +#undef blk_fill_rwbs
> +#undef blk_fill_rwbs_rq
> +
> #endif /* _TRACE_BLOCK_H */
>
> /* This part must be outside protection */
> Index: linux-2.6-lttng/include/linux/blktrace_api.h
> ===================================================================
> --- linux-2.6-lttng.orig/include/linux/blktrace_api.h
> +++ linux-2.6-lttng/include/linux/blktrace_api.h
> @@ -236,18 +236,5 @@ struct compat_blk_user_trace_setup {
>
> #endif
>
> -#if defined(CONFIG_EVENT_TRACING) && defined(CONFIG_BLOCK)
> -
> -static inline int blk_cmd_buf_len(struct request *rq)
> -{
> - return (rq->cmd_type == REQ_TYPE_BLOCK_PC) ? rq->cmd_len * 3 : 1;
> -}
> -
> -extern void blk_dump_cmd(char *buf, struct request *rq);
> -extern void blk_fill_rwbs(char *rwbs, u32 rw, int bytes);
> -extern void blk_fill_rwbs_rq(char *rwbs, struct request *rq);
> -
> -#endif /* CONFIG_EVENT_TRACING && CONFIG_BLOCK */
> -
> #endif /* __KERNEL__ */
> #endif
> Index: linux-2.6-lttng/kernel/trace/blktrace.c
> ===================================================================
> --- linux-2.6-lttng.orig/kernel/trace/blktrace.c
> +++ linux-2.6-lttng/kernel/trace/blktrace.c
> @@ -26,6 +26,7 @@
> #include <linux/smp_lock.h>
> #include <linux/time.h>
> #include <linux/uaccess.h>
> +#include <linux/trace_seq.h>
>
> #include <trace/events/block.h>
>
> @@ -1773,15 +1774,14 @@ void blk_trace_remove_sysfs(struct devic
>
> #ifdef CONFIG_EVENT_TRACING
>
> -void blk_dump_cmd(char *buf, struct request *rq)
> +const char *blk_dump_cmd(struct trace_seq *p, unsigned char *cmd, int len)
> {
> + const char *ret = p->buffer + p->len;
> int i, end;
> - int len = rq->cmd_len;
> - unsigned char *cmd = rq->cmd;
>
> - if (rq->cmd_type != REQ_TYPE_BLOCK_PC) {
> - buf[0] = '\0';
> - return;
> + if (!len) {
> + trace_seq_putc(p, 0);
> + return ret;
> }
>
> for (end = len - 1; end >= 0; end--)
> @@ -1790,55 +1790,14 @@ void blk_dump_cmd(char *buf, struct requ
> end++;
>
> for (i = 0; i < len; i++) {
> - buf += sprintf(buf, "%s%02x", i == 0 ? "" : " ", cmd[i]);
> + trace_seq_printf(p, "%s%02x", i == 0 ? "" : " ", cmd[i]);
> if (i == end && end != len - 1) {
> - sprintf(buf, " ..");
> + trace_seq_printf(p, " ..");
> break;
> }
> }
> -}
> -
> -void blk_fill_rwbs(char *rwbs, u32 rw, int bytes)
> -{
> - int i = 0;
> -
> - if (rw & WRITE)
> - rwbs[i++] = 'W';
> - else if (rw & REQ_DISCARD)
> - rwbs[i++] = 'D';
> - else if (bytes)
> - rwbs[i++] = 'R';
> - else
> - rwbs[i++] = 'N';
> -
> - if (rw & REQ_RAHEAD)
> - rwbs[i++] = 'A';
> - if (rw & REQ_HARDBARRIER)
> - rwbs[i++] = 'B';
> - if (rw & REQ_SYNC)
> - rwbs[i++] = 'S';
> - if (rw & REQ_META)
> - rwbs[i++] = 'M';
> - if (rw & REQ_SECURE)
> - rwbs[i++] = 'E';
> -
> - rwbs[i] = '\0';
> -}
> -
> -void blk_fill_rwbs_rq(char *rwbs, struct request *rq)
> -{
> - int rw = rq->cmd_flags & 0x03;
> - int bytes;
> -
> - if (rq->cmd_flags & REQ_DISCARD)
> - rw |= REQ_DISCARD;
> -
> - if (rq->cmd_flags & REQ_SECURE)
> - rw |= REQ_SECURE;
> -
> - bytes = blk_rq_bytes(rq);
> -
> - blk_fill_rwbs(rwbs, rw, bytes);
> + trace_seq_putc(p, 0);
> + return ret;
> }
>
> #endif /* CONFIG_EVENT_TRACING */