From: Eric Ren <zren@suse.com>
To: ocfs2-devel@oss.oracle.com
Subject: [Ocfs2-devel] Long io response time doubt
Date: Tue, 24 Nov 2015 18:05:40 +0800 [thread overview]
Message-ID: <56543674.6060809@suse.com> (raw)
In-Reply-To: <565435C6.4050601@suse.com>
Sorry, forget to add the pieces of code flow...
On reading node:
3) dlm_ast-4278 => ocfs2dc-4277
------------------------------------------
3) | ocfs2_process_blocked_lock() {
3) | ocfs2_unblock_lock() {
3) 0.116 us | ocfs2_prepare_cancel_convert();
3) | ocfs2_cancel_convert() {
3) | user_dlm_unlock() {
3) | dlm_unlock() {
3) 0.120 us | dlm_find_lockspace_local();
3) 0.158 us | find_lkb();
3) | cancel_lock() {
3) | validate_unlock_args() {
3) 0.093 us | del_timeout();
3) 0.782 us | }
3) | _cancel_lock() {
3) | send_common() {
3) 0.189 us | add_to_waiters();
3) | create_message() {
3) | _create_message() {
3) | dlm_lowcomms_get_buffer() {
3) 0.156 us | nodeid2con();
3) 1.680 us | }
3) 0.108 us | dlm_our_nodeid();
3) 2.821 us | }
3) 3.319 us | }
3) 0.094 us | send_args();
3) | send_message() {
3) 0.070 us | dlm_message_out();
3) 9.485 us | dlm_lowcomms_commit_buffer();
3) + 10.609 us | }
3) + 16.054 us | }
3) + 16.632 us | }
3) 0.156 us | put_rsb();
3) + 19.044 us | }
3) | dlm_put_lkb() {
3) 0.094 us | __put_lkb();
3) 0.632 us | }
3) 0.074 us | dlm_put_lockspace();
3) + 22.513 us | }
3) + 23.028 us | }
3) + 23.727 us | }
3) + 25.004 us | }
3) | ocfs2_schedule_blocked_lock() {
3) 0.073 us | lockres_set_flags();
3) 0.592 us | }
3) + 26.852 us | }
------------------------------------------
3) ocfs2dc-4277 => dlm_ast-4278
------------------------------------------
3) | process_asts() {
3) 0.202 us | dlm_rem_lkb_callback();
3) 0.081 us | dlm_rem_lkb_callback();
3) | fsdlm_lock_ast_wrapper() {
3) | ocfs2_unlock_ast() {
3) 0.099 us | ocfs2_get_inode_osb();
3) 1.290 us | ocfs2_wake_downconvert_thread();
3) | lockres_clear_flags() {
3) 8.539 us | lockres_set_flags();
3) 9.096 us | }
3) + 12.055 us | }
3) + 12.673 us | }
3) | dlm_put_lkb() {
3) 0.161 us | __put_lkb();
3) 0.718 us | }
3) + 16.133 us | }
On writing node:
3) kworker-443 => ocfs2dc-4456
------------------------------------------
3) | ocfs2_process_blocked_lock() {
3) | ocfs2_unblock_lock() {
3) 0.269 us | ocfs2_prepare_cancel_convert();
3) | ocfs2_cancel_convert() {
3) | user_dlm_unlock() {
3) | dlm_unlock() {
3) 0.321 us | dlm_find_lockspace_local();
3) 0.286 us | find_lkb();
3) | cancel_lock() {
3) | validate_unlock_args() {
3) 0.122 us | del_timeout();
3) 0.901 us | }
3) | _cancel_lock() {
3) | do_cancel() {
3) | revert_lock() {
3) | move_lkb() {
3) 0.155 us | del_lkb();
3) 0.243 us | add_lkb();
3) 1.778 us | }
3) 2.577 us | }
3) | queue_cast() {
3) 0.102 us | del_timeout();
3) | dlm_add_ast() {
3) 0.165 us | dlm_add_lkb_callback();
3) + 14.492 us | }
3) + 16.381 us | }
3) + 20.384 us | }
3) | grant_pending_locks() {
3) | grant_pending_convert() {
3) | can_be_granted() {
3) 0.143 us | _can_be_granted();
3) 0.906 us | }
3) 1.900 us | }
3) 2.738 us | }
3) + 24.670 us | }
3) 0.154 us | put_rsb();
3) + 28.068 us | }
3) | dlm_put_lkb() {
3) 0.163 us | __put_lkb();
3) 1.029 us | }
3) 0.195 us | dlm_put_lockspace();
3) + 34.035 us | }
3) + 34.914 us | }
3) + 35.919 us | }
3) + 37.864 us | }
3) | ocfs2_schedule_blocked_lock() {
3) 0.210 us | lockres_set_flags();
0) | process_asts() {
3) 0.998 us | }
0) 0.215 us | dlm_rem_lkb_callback();
3) + 40.671 us | }
0) 0.084 us | dlm_rem_lkb_callback();
0) | fsdlm_lock_ast_wrapper() {
0) | ocfs2_unlock_ast() {
0) 0.088 us | ocfs2_get_inode_osb();
0) 9.498 us | ocfs2_wake_downconvert_thread();
0) | lockres_clear_flags() {
0) 1.272 us | lockres_set_flags();
0) 1.757 us | }
0) + 13.396 us | }
0) + 13.983 us | }
0) | dlm_put_lkb() {
0) 0.136 us | __put_lkb();
0) 0.641 us | }
0) + 17.224 us | }
Thank,
Eric
On 11/24/15 18:02, Eric Ren wrote:
> Hi Joseph,
>
> I use ftrace's function tracer to record some code flow. There's a
> question that makes me confused -
> why does ocfs2_cancel_convert() be called here in ocfs2dc thread? In
> other words, what do we expect it
> to do here?
>
> ocfs2_unblock_lock(){
> ...
> if(lockres->l_flags & OCFS2_LOCK_BUSY){
> ...
> ocfs2_cancel_convert()
> ...
> }
> }
>
> From what I understand,
> ocfs2_cancel_convert()->ocfs2_dlm_unlock()->user_dlm_unlock()->dlm_unlock(DLM_LKF_CANCEL)
> puts
> the lock back on the the grand queue at its old grant mode. In my
> case, you know, read/write the same shared file from two nodes,
> I think the up-conversion can only happen on the writing node -
> (PR->EX), while on the reading node, no up-conversion is need, right?
>
> But, the following output from writing and reading nodes, shows that
> ocfs2_cancel_convert() has been called on both nodes. why could
> this happen in this scenario?
>
> On 11/16/15 09:40, Joseph Qi wrote:
>>> Sorry, I'm confused about b). You mean b) is also part of ocfs2cmt's
>>> work? Does b) have something to do with a)? And what's the meaning
>>> of "evict inode"?
>>> Actually, I can hardly understand the idea of b).
>> You can go through the code flow:
>> iput->iput_final->evict->evict_inode->ocfs2_evict_inode
>> ->ocfs2_clear_inode->ocfs2_checkpoint_inode->ocfs2_start_checkpoint
>>
>> It happens that one node do not use the inode any longer (but not
>> delete), and will free its related lockres.
> OK, thanks~
>
> Eric
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next prev parent reply other threads:[~2015-11-24 10:05 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-11-12 3:05 [Ocfs2-devel] Long io response time doubt Joseph Qi
2015-11-12 7:23 ` Eric Ren
2015-11-12 8:00 ` Joseph Qi
2015-11-12 9:48 ` Eric Ren
2015-11-13 3:31 ` Joseph Qi
2015-11-14 5:23 ` Eric Ren
2015-11-16 1:40 ` Joseph Qi
2015-11-24 10:02 ` Eric Ren
2015-11-24 10:05 ` Eric Ren [this message]
2015-11-26 1:34 ` Joseph Qi
2015-11-26 1:49 ` Eric Ren
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