lkml.org 
[lkml]   [2011]   [Mar]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH] blktrace: Use rq->cmd_flags directly in blk_add_trace_rq.
    Date
    From: Tao Ma <boyu.mt@taobao.com>

    In blk_add_trace_rq, we only chose the minor 2 bits from
    request's cmd_flags and did some check for discard.
    so most of other flags(e.g, REQ_SYNC) are missing.

    For example, with a sync write after blkparse we get:
    8,16 1 1 0.001776503 7509 A WS 1349632 + 1024 <- (8,17) 1347584
    8,16 1 2 0.001776813 7509 Q WS 1349632 + 1024 [dd]
    8,16 1 3 0.001780395 7509 G WS 1349632 + 1024 [dd]
    8,16 1 5 0.001783186 7509 I W 1349632 + 1024 [dd]
    8,16 1 11 0.001816987 7509 D W 1349632 + 1024 [dd]
    8,16 0 2 0.006218192 0 C W 1349632 + 1024 [0]

    Since now we have integrated the flags of both bio and request,
    it is safe to pass rq->cmd_flags directly to __blk_add_trace.

    With this patch, after a sync write we get:
    8,16 1 1 0.001776900 5425 A WS 1189888 + 1024 <- (8,17) 1187840
    8,16 1 2 0.001777179 5425 Q WS 1189888 + 1024 [dd]
    8,16 1 3 0.001780797 5425 G WS 1189888 + 1024 [dd]
    8,16 1 5 0.001783402 5425 I WS 1189888 + 1024 [dd]
    8,16 1 11 0.001817468 5425 D WS 1189888 + 1024 [dd]
    8,16 0 2 0.005640709 0 C WS 1189888 + 1024 [0]

    Cc: Jens Axboe <jaxboe@fusionio.com>
    Signed-off-by: Tao Ma <boyu.mt@taobao.com>
    ---
    kernel/trace/blktrace.c | 15 ++++-----------
    1 files changed, 4 insertions(+), 11 deletions(-)

    diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
    index cbafed7..7aa40f8 100644
    --- a/kernel/trace/blktrace.c
    +++ b/kernel/trace/blktrace.c
    @@ -703,28 +703,21 @@ void blk_trace_shutdown(struct request_queue *q)
    *
    **/
    static void blk_add_trace_rq(struct request_queue *q, struct request *rq,
    - u32 what)
    + u32 what)
    {
    struct blk_trace *bt = q->blk_trace;
    - int rw = rq->cmd_flags & 0x03;

    if (likely(!bt))
    return;

    - if (rq->cmd_flags & REQ_DISCARD)
    - rw |= REQ_DISCARD;
    -
    - if (rq->cmd_flags & REQ_SECURE)
    - rw |= REQ_SECURE;
    -
    if (rq->cmd_type == REQ_TYPE_BLOCK_PC) {
    what |= BLK_TC_ACT(BLK_TC_PC);
    - __blk_add_trace(bt, 0, blk_rq_bytes(rq), rw,
    + __blk_add_trace(bt, 0, blk_rq_bytes(rq), rq->cmd_flags,
    what, rq->errors, rq->cmd_len, rq->cmd);
    } else {
    what |= BLK_TC_ACT(BLK_TC_FS);
    - __blk_add_trace(bt, blk_rq_pos(rq), blk_rq_bytes(rq), rw,
    - what, rq->errors, 0, NULL);
    + __blk_add_trace(bt, blk_rq_pos(rq), blk_rq_bytes(rq),
    + rq->cmd_flags, what, rq->errors, 0, NULL);
    }
    }

    --
    1.6.3.GIT


    \
     
     \ /
      Last update: 2011-03-04 07:19    [W:0.032 / U:0.072 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site