lkml.org 
[lkml]   [2019]   [Apr]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    Date
    From
    Subject[patch V3 15/29] dm persistent data: Simplify stack trace handling
    Replace the indirection through struct stack_trace with an invocation of
    the storage array based interface. This results in less storage space and
    indirection.

    Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
    Cc: dm-devel@redhat.com
    Cc: Mike Snitzer <snitzer@redhat.com>
    Cc: Alasdair Kergon <agk@redhat.com>
    ---
    drivers/md/persistent-data/dm-block-manager.c | 19 +++++++++----------
    1 file changed, 9 insertions(+), 10 deletions(-)

    --- a/drivers/md/persistent-data/dm-block-manager.c
    +++ b/drivers/md/persistent-data/dm-block-manager.c
    @@ -35,7 +35,10 @@
    #define MAX_HOLDERS 4
    #define MAX_STACK 10

    -typedef unsigned long stack_entries[MAX_STACK];
    +struct stack_store {
    + unsigned int nr_entries;
    + unsigned long entries[MAX_STACK];
    +};

    struct block_lock {
    spinlock_t lock;
    @@ -44,8 +47,7 @@ struct block_lock {
    struct task_struct *holders[MAX_HOLDERS];

    #ifdef CONFIG_DM_DEBUG_BLOCK_STACK_TRACING
    - struct stack_trace traces[MAX_HOLDERS];
    - stack_entries entries[MAX_HOLDERS];
    + struct stack_store traces[MAX_HOLDERS];
    #endif
    };

    @@ -73,7 +75,7 @@ static void __add_holder(struct block_lo
    {
    unsigned h = __find_holder(lock, NULL);
    #ifdef CONFIG_DM_DEBUG_BLOCK_STACK_TRACING
    - struct stack_trace *t;
    + struct stack_store *t;
    #endif

    get_task_struct(task);
    @@ -81,11 +83,7 @@ static void __add_holder(struct block_lo

    #ifdef CONFIG_DM_DEBUG_BLOCK_STACK_TRACING
    t = lock->traces + h;
    - t->nr_entries = 0;
    - t->max_entries = MAX_STACK;
    - t->entries = lock->entries[h];
    - t->skip = 2;
    - save_stack_trace(t);
    + t->nr_entries = stack_trace_save(t->entries, MAX_STACK, 2);
    #endif
    }

    @@ -106,7 +104,8 @@ static int __check_holder(struct block_l
    DMERR("recursive lock detected in metadata");
    #ifdef CONFIG_DM_DEBUG_BLOCK_STACK_TRACING
    DMERR("previously held here:");
    - print_stack_trace(lock->traces + i, 4);
    + stack_trace_print(lock->traces[i].entries,
    + lock->traces[i].nr_entries, 4);

    DMERR("subsequent acquisition attempted here:");
    dump_stack();

    \
     
     \ /
      Last update: 2019-04-25 12:03    [W:4.187 / U:0.080 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site