xfs
[Top] [All Lists]

RE: [PATCH 7/6] XFS: Add trace points for per-ag refcount debugging.

To: "Dave Chinner" <david@xxxxxxxxxxxxx>
Subject: RE: [PATCH 7/6] XFS: Add trace points for per-ag refcount debugging.
From: "Alex Elder" <aelder@xxxxxxx>
Date: Tue, 5 Jan 2010 12:08:22 -0600
Cc: <xfs@xxxxxxxxxxx>
In-reply-to: <20091220042813.GJ4850@xxxxxxxxxxxxxxxx>
Thread-index: AcqBLSji2hP0g8pARuWY5fegAjor1gNBM/eQ
Thread-topic: [PATCH 7/6] XFS: Add trace points for per-ag refcount debugging.
Dave Chinner wrote:
> Uninline xfs_perag_{get,put} so that tracepoints can be inserted
> into them to speed debugging of reference count problems.

Looks good.

> Signed-off-by: Dave Chinner <david@xxxxxxxxxxxxx>

Reviewed-by: Alex Elder <aelder@xxxxxxx>

> ---
>  fs/xfs/linux-2.6/xfs_trace.h |   27 +++++++++++++++++++++++++++
>  fs/xfs/xfs_ag.h              |    2 ++
>  fs/xfs/xfs_mount.c           |   34 ++++++++++++++++++++++++++++++++++
>  fs/xfs/xfs_mount.h           |   25 ++-----------------------
>  4 files changed, 65 insertions(+), 23 deletions(-)
> 
> diff --git a/fs/xfs/linux-2.6/xfs_trace.h b/fs/xfs/linux-2.6/xfs_trace.h
> index d4ded59..5ec1475 100644
> --- a/fs/xfs/linux-2.6/xfs_trace.h
> +++ b/fs/xfs/linux-2.6/xfs_trace.h
> @@ -33,6 +33,33 @@ struct xfs_dquot;
>  struct xlog_ticket;
>  struct log;
> 
> +#define DEFINE_PERAG_REF_EVENT(name) \
> +TRACE_EVENT(name, \
> +     TP_PROTO(struct xfs_mount *mp, xfs_agnumber_t agno, int refcount, \
> +              unsigned long caller_ip), \
> +     TP_ARGS(mp, agno, refcount, caller_ip), \
> +     TP_STRUCT__entry( \
> +             __field(dev_t, dev) \
> +             __field(xfs_agnumber_t, agno) \
> +             __field(int, refcount) \
> +             __field(unsigned long, caller_ip) \
> +     ), \
> +     TP_fast_assign( \
> +             __entry->dev = mp->m_super->s_dev; \
> +             __entry->agno = agno; \
> +             __entry->refcount = refcount; \
> +             __entry->caller_ip = caller_ip; \
> +     ), \
> +     TP_printk("dev %d:%d agno %u refcount %d caller %pf", \
> +               MAJOR(__entry->dev), MINOR(__entry->dev), \
> +               __entry->agno, \
> +               __entry->refcount, \
> +               (char *)__entry->caller_ip) \
> +);
> +
> +DEFINE_PERAG_REF_EVENT(xfs_perag_get)
> +DEFINE_PERAG_REF_EVENT(xfs_perag_put)
> +
>  #define DEFINE_ATTR_LIST_EVENT(name) \
>  TRACE_EVENT(name, \
>       TP_PROTO(struct xfs_attr_list_context *ctx), \
> diff --git a/fs/xfs/xfs_ag.h b/fs/xfs/xfs_ag.h
> index 18ae43f..963bc27 100644
> --- a/fs/xfs/xfs_ag.h
> +++ b/fs/xfs/xfs_ag.h
> @@ -197,6 +197,8 @@ typedef struct xfs_perag_busy {
>  #endif
> 
>  typedef struct xfs_perag {
> +     struct xfs_mount *pag_mount;    /* owner filesystem */
> +     xfs_agnumber_t  pag_agno;       /* AG this structure belongs to */
>       atomic_t        pag_ref;        /* perag reference count */
>       char            pagf_init;      /* this agf's entry is initialized */
>       char            pagi_init;      /* this agi's entry is initialized */
> diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
> index 1d00f7f..223d9c3 100644
> --- a/fs/xfs/xfs_mount.c
> +++ b/fs/xfs/xfs_mount.c
> @@ -201,6 +201,38 @@ xfs_uuid_unmount(
> 
> 
>  /*
> + * Reference counting access wrappers to the perag structures.
> + */
> +struct xfs_perag *
> +xfs_perag_get(struct xfs_mount *mp, xfs_agnumber_t agno)
> +{
> +     struct xfs_perag        *pag;
> +     int                     ref = 0;
> +
> +     spin_lock(&mp->m_perag_lock);
> +     pag = radix_tree_lookup(&mp->m_perag_tree, agno);
> +     if (pag) {
> +             ASSERT(atomic_read(&pag->pag_ref) >= 0);
> +             /* catch leaks in the positive direction during testing */
> +             ASSERT(atomic_read(&pag->pag_ref) < 1000);
> +             ref = atomic_inc_return(&pag->pag_ref);
> +     }
> +     spin_unlock(&mp->m_perag_lock);
> +     trace_xfs_perag_get(mp, agno, ref, _RET_IP_);
> +     return pag;
> +}
> +
> +void
> +xfs_perag_put(struct xfs_perag *pag)
> +{
> +     int     ref;
> +
> +     ASSERT(atomic_read(&pag->pag_ref) > 0);
> +     ref = atomic_dec_return(&pag->pag_ref);
> +     trace_xfs_perag_put(pag->pag_mount, pag->pag_agno, ref, _RET_IP_);
> +}
> +
> +/*
>   * Free up the resources associated with a mount structure.  Assume that
>   * the structure was initially zeroed, so we can tell which fields got
>   * initialized.
> @@ -433,6 +465,8 @@ xfs_initialize_perag(
>                       kmem_free(pag);
>                       return -EEXIST;
>               }
> +             pag->pag_agno = index;
> +             pag->pag_mount = mp;
>               spin_unlock(&mp->m_perag_lock);
>               radix_tree_preload_end();
>       }
> diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
> index 16b2212..e62fd1c 100644
> --- a/fs/xfs/xfs_mount.h
> +++ b/fs/xfs/xfs_mount.h
> @@ -386,29 +386,8 @@ xfs_daddr_to_agbno(struct xfs_mount *mp, xfs_daddr_t d)
>  /*
>   * perag get/put wrappers for ref counting
>   */
> -static inline struct xfs_perag *
> -xfs_perag_get(struct xfs_mount *mp, xfs_agnumber_t agno)
> -{
> -     struct xfs_perag        *pag;
> -
> -     spin_lock(&mp->m_perag_lock);
> -     pag = radix_tree_lookup(&mp->m_perag_tree, agno);
> -     if (pag) {
> -             ASSERT(atomic_read(&pag->pag_ref) >= 0);
> -             /* catch leaks in the positive direction during testing */
> -             ASSERT(atomic_read(&pag->pag_ref) < 1000);
> -             atomic_inc(&pag->pag_ref);
> -     }
> -     spin_unlock(&mp->m_perag_lock);
> -     return pag;
> -}
> -
> -static inline void
> -xfs_perag_put(struct xfs_perag *pag)
> -{
> -     ASSERT(atomic_read(&pag->pag_ref) > 0);
> -     atomic_dec(&pag->pag_ref);
> -}
> +struct xfs_perag *xfs_perag_get(struct xfs_mount *mp, xfs_agnumber_t agno);
> +void xfs_perag_put(struct xfs_perag *pag);
> 
>  /*
>   * Per-cpu superblock locking functions
> 
> _______________________________________________
> xfs mailing list
> xfs@xxxxxxxxxxx
> http://oss.sgi.com/mailman/listinfo/xfs

<Prev in Thread] Current Thread [Next in Thread>
  • RE: [PATCH 7/6] XFS: Add trace points for per-ag refcount debugging., Alex Elder <=