On Thu, Apr 13, 2023 at 02:10:32PM +0530, Ritesh Harjani (IBM) wrote:
> This patch adds trace point events for iomap DIO path.
>
> <e.g. iomap dio trace>
> xfs_io-8815 [000] 526.790418: iomap_dio_rw_begin: dev 7:7 ino 0xc isize 0x0 pos 0x0 count 4096 flags DIRECT dio_flags DIO_FORCE_WAIT done_before 0 aio 0 ret 0
> xfs_io-8815 [000] 526.790978: iomap_dio_complete: dev 7:7 ino 0xc isize 0x1000 pos 0x1000 flags DIRECT aio 0 error 0 ret 4096
> xfs_io-8815 [000] 526.790988: iomap_dio_rw_end: dev 7:7 ino 0xc isize 0x1000 pos 0x1000 count 0 flags DIRECT dio_flags DIO_FORCE_WAIT done_before 0 aio 0 ret 4096
> fsx-8827 [005] 526.939345: iomap_dio_rw_begin: dev 7:7 ino 0xc isize 0x922f8 pos 0x4f000 count 61440 flags NOWAIT|DIRECT|ALLOC_CACHE dio_flags done_before 0 aio 1 ret 0
> fsx-8827 [005] 526.939459: iomap_dio_rw_end: dev 7:7 ino 0xc isize 0x922f8 pos 0x4f000 count 0 flags NOWAIT|DIRECT|ALLOC_CACHE dio_flags done_before 0 aio 1 ret -529
> ksoftirqd/5-41 [005] 526.939564: iomap_dio_complete: dev 7:7 ino 0xc isize 0x922f8 pos 0x5e000 flags NOWAIT|DIRECT|ALLOC_CACHE aio 1 error 0 ret 61440
>
> Tested-by: Disha Goel <disgoel@xxxxxxxxxxxxx>
> Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@xxxxxxxxx>
> ---
> fs/iomap/direct-io.c | 3 ++
> fs/iomap/trace.c | 1 +
> fs/iomap/trace.h | 90 ++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 94 insertions(+)
>
> diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
> index 5871956ee880..bb7a6dfbc8b3 100644
> --- a/fs/iomap/direct-io.c
> +++ b/fs/iomap/direct-io.c
> @@ -130,6 +130,7 @@ ssize_t iomap_dio_complete(struct iomap_dio *dio)
> if (ret > 0)
> ret += dio->done_before;
>
> + trace_iomap_dio_complete(iocb, dio->error, ret);
> kfree(dio);
>
> return ret;
> @@ -681,6 +682,7 @@ iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
> struct iomap_dio *dio;
> ssize_t ret = 0;
>
> + trace_iomap_dio_rw_begin(iocb, iter, dio_flags, done_before, ret);
> dio = __iomap_dio_rw(iocb, iter, ops, dops, dio_flags, private,
> done_before);
> if (IS_ERR_OR_NULL(dio)) {
> @@ -689,6 +691,7 @@ iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
> }
> ret = iomap_dio_complete(dio);
> out:
> + trace_iomap_dio_rw_end(iocb, iter, dio_flags, done_before, ret);
> return ret;
> }
> EXPORT_SYMBOL_GPL(iomap_dio_rw);
> diff --git a/fs/iomap/trace.c b/fs/iomap/trace.c
> index da217246b1a9..728d5443daf5 100644
> --- a/fs/iomap/trace.c
> +++ b/fs/iomap/trace.c
> @@ -3,6 +3,7 @@
> * Copyright (c) 2019 Christoph Hellwig
> */
> #include <linux/iomap.h>
> +#include <linux/uio.h>
>
> /*
> * We include this last to have the helpers above available for the trace
> diff --git a/fs/iomap/trace.h b/fs/iomap/trace.h
> index f6ea9540d082..dcb4dd4db5fb 100644
> --- a/fs/iomap/trace.h
> +++ b/fs/iomap/trace.h
> @@ -183,6 +183,96 @@ TRACE_EVENT(iomap_iter,
> (void *)__entry->caller)
> );
>
> +#define TRACE_IOMAP_DIO_STRINGS \
> + {IOMAP_DIO_FORCE_WAIT, "DIO_FORCE_WAIT" }, \
> + {IOMAP_DIO_OVERWRITE_ONLY, "DIO_OVERWRITE_ONLY" }, \
> + {IOMAP_DIO_PARTIAL, "DIO_PARTIAL" }
Can you make the strings line up too, please?
> +
> +DECLARE_EVENT_CLASS(iomap_dio_class,
> + TP_PROTO(struct kiocb *iocb, struct iov_iter *iter,
> + unsigned int dio_flags, u64 done_before, int ret),
We're passing in ssize_t values for @ret, shouldn't the types match?
> + TP_ARGS(iocb, iter, dio_flags, done_before, ret),
> + TP_STRUCT__entry(
> + __field(dev_t, dev)
> + __field(ino_t, ino)
> + __field(loff_t, isize)
> + __field(loff_t, pos)
> + __field(u64, count)
What's the difference between "length" as used in the other tracepoints
and "count" here?
> + __field(u64, done_before)
> + __field(int, ki_flags)
> + __field(unsigned int, dio_flags)
> + __field(bool, aio)
> + __field(int, ret)
> + ),
> + TP_fast_assign(
> + __entry->dev = file_inode(iocb->ki_filp)->i_sb->s_dev;
> + __entry->ino = file_inode(iocb->ki_filp)->i_ino;
> + __entry->isize = file_inode(iocb->ki_filp)->i_size;
> + __entry->pos = iocb->ki_pos;
> + __entry->count = iov_iter_count(iter);
> + __entry->done_before = done_before;
> + __entry->dio_flags = dio_flags;
> + __entry->ki_flags = iocb->ki_flags;
> + __entry->aio = !is_sync_kiocb(iocb);
> + __entry->ret = ret;
> + ),
> + TP_printk("dev %d:%d ino 0x%lx isize 0x%llx pos 0x%llx count %llu "
count and done_before are lengths of file operations, in bytes, right?
Everywhere else we use 0x%llx for that.
> + "flags %s dio_flags %s done_before %llu aio %d ret %d",
> + MAJOR(__entry->dev), MINOR(__entry->dev),
> + __entry->ino,
> + __entry->isize,
> + __entry->pos,
> + __entry->count,
> + __print_flags(__entry->ki_flags, "|", TRACE_IOCB_STRINGS),
> + __print_flags(__entry->dio_flags, "|", TRACE_IOMAP_DIO_STRINGS),
> + __entry->done_before,
> + __entry->aio,
> + __entry->ret)
> +)
> +
> +#define DEFINE_DIO_RW_EVENT(name) \
> +DEFINE_EVENT(iomap_dio_class, name, \
> + TP_PROTO(struct kiocb *iocb, struct iov_iter *iter, \
> + unsigned int dio_flags, u64 done_before, \
> + int ret), \
> + TP_ARGS(iocb, iter, dio_flags, done_before, ret))
> +DEFINE_DIO_RW_EVENT(iomap_dio_rw_begin);
> +DEFINE_DIO_RW_EVENT(iomap_dio_rw_end);
> +
> +TRACE_EVENT(iomap_dio_complete,
> + TP_PROTO(struct kiocb *iocb, int error, int ret),
> + TP_ARGS(iocb, error, ret),
> + TP_STRUCT__entry(
> + __field(dev_t, dev)
> + __field(ino_t, ino)
> + __field(loff_t, isize)
> + __field(loff_t, pos)
> + __field(int, ki_flags)
> + __field(bool, aio)
> + __field(int, error)
> + __field(int, ret)
Same comment about @ret and ssize_t here.
--D
> + ),
> + TP_fast_assign(
> + __entry->dev = file_inode(iocb->ki_filp)->i_sb->s_dev;
> + __entry->ino = file_inode(iocb->ki_filp)->i_ino;
> + __entry->isize = file_inode(iocb->ki_filp)->i_size;
> + __entry->pos = iocb->ki_pos;
> + __entry->ki_flags = iocb->ki_flags;
> + __entry->aio = !is_sync_kiocb(iocb);
> + __entry->error = error;
> + __entry->ret = ret;
> + ),
> + TP_printk("dev %d:%d ino 0x%lx isize 0x%llx pos 0x%llx flags %s aio %d error %d ret %d",
> + MAJOR(__entry->dev), MINOR(__entry->dev),
> + __entry->ino,
> + __entry->isize,
> + __entry->pos,
> + __print_flags(__entry->ki_flags, "|", TRACE_IOCB_STRINGS),
> + __entry->aio,
> + __entry->error,
> + __entry->ret)
> +);
> +
> #endif /* _IOMAP_TRACE_H */
>
> #undef TRACE_INCLUDE_PATH
> --
> 2.39.2
>
