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

Mathieu Desnoyers
2010-12-20T22:39:36Z

By the way, the event "block_bio_complete" does not set the value of the "error"
field, leaving it as garbage. What would be the appropriate course of action to
fix this: remove the field or find some input data to feed into it ?

Thanks,

Mathieu

* Jeff Moyer (jmoyer@redhat.com) wrote:
> 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 */

--
Mathieu Desnoyers
Operating System Efficiency R&D Consultant
EfficiOS Inc.