On 2012-08-10 21:09 Jens Axboe <jax...@fusionio.com> Wrote: >On 08/10/2012 01:46 PM, Jianpeng Ma wrote: >> If process handled two or more devices,there will not be trace some >> devices plug-operation. >> >> Signed-off-by: Jianpeng Ma <majianp...@gmail.com> >> --- >> block/blk-core.c | 16 +++++++++++++++- >> 1 file changed, 15 insertions(+), 1 deletion(-) >> >> diff --git a/block/blk-core.c b/block/blk-core.c >> index 7a3abc6..034f186 100644 >> --- a/block/blk-core.c >> +++ b/block/blk-core.c >> @@ -1521,11 +1521,25 @@ get_rq: >> struct request *__rq; >> >> __rq = list_entry_rq(plug->list.prev); >> - if (__rq->q != q) >> + if (__rq->q != q) { >> plug->should_sort = 1; >> + trace_block_plug(q); >> + } >> + } else { >> + struct request *__rq; >> + list_for_each_entry_reverse(__rq, &plug->list, >> + queuelist) { >> + if (__rq->q == q) { >> + list_add_tail(&req->queuelist, >> + &__rq->queuelist); >> + goto stat_acct; > >Did you verify this? It doesn't look right to me. You browse the list in >reverse, which means __rq is the first one that has a matching q. Then >you add the new req IN FRONT of that. You would want list_add() here >instead, adding it as the last member of that q string, not in the >middle. > >-- >Jens Axboe > Hi all: How about those patches? Ok or wrong? Thanks!N�Р骒r��y����b�X�肚�v�^�)藓{.n�+�伐�{��赙zXФ�≤�}��财�z�&j:+v�����赙zZ+��+zf"�h���~����i���z��wア�?�ㄨ��&�)撷f��^j谦y�m��@A�a囤� 0鹅h���i