From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steve French Subject: Fwd: [PATCH 3/7] cifs: No need to send SIGKILL to demux_thread during umount Date: Tue, 16 Sep 2014 13:47:38 -0500 Message-ID: References: <003601cfbc62$fe88d170$fb9a7450$@samsung.com> <20140821073846.660b718a@tlielax.poochiereds.net> <004101cfd186$33aa37d0$9afea770$@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 To: "linux-cifs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" Return-path: In-Reply-To: Sender: linux-cifs-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: cc list ---------- Forwarded message ---------- From: Steve French Date: Tue, Sep 16, 2014 at 1:46 PM Subject: Re: [PATCH 3/7] cifs: No need to send SIGKILL to demux_thread during umount To: Namjae Jeon Cc: Jeff Layton , Pavel Shilovsky reverted in cifs-2.6.git On Tue, Sep 16, 2014 at 3:14 AM, Namjae Jeon wrote: >> I think this patch may be slowing down the ability to do rmmod after >> cifs umount (have to wait about 10-20 seconds) since it thinks the >> cifs module is in use longer now > Hi Steve, > > your concern is correct, rmmod time is increased from 1 second to 7 seconds. > The reason is why thread is sleeping interruptible in interuptibble state, > signal delivering wakes up the thread early otherwise it is wake up after > 7 seconds after timeout expires.. > > Sorry, Could you revert this patch ? > > Thanks. > >> >> >> ---------- Forwarded message ---------- >> From: Jeff Layton >> Date: Thu, Aug 21, 2014 at 4:38 AM >> Subject: Re: [PATCH 3/7] cifs: No need to send SIGKILL to demux_thread >> during umount >> To: Namjae Jeon >> Cc: Steve French , Shirish Pargaonkar >> , Pavel Shilovsky , >> linux-cifs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Ashish Sangwan >> >> >> On Wed, 20 Aug 2014 19:39:17 +0900 >> Namjae Jeon wrote: >> >> > There is no need to explicitly send SIGKILL to cifs_demultiplex_thread >> > as it is calling module_put_and_exit to exit cleanly. >> > >> > socket sk_rcvtimeo is set to 7 HZ so the thread will wake up in 7 seconds and >> > clean itself. >> > >> > Signed-off-by: Namjae Jeon >> > Signed-off-by: Ashish Sangwan >> > --- >> > fs/cifs/connect.c | 19 ------------------- >> > 1 files changed, 0 insertions(+), 19 deletions(-) >> > >> > diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c >> > index 03ed8a0..b4b6d10 100644 >> > --- a/fs/cifs/connect.c >> > +++ b/fs/cifs/connect.c >> > @@ -837,7 +837,6 @@ cifs_demultiplex_thread(void *p) >> > struct TCP_Server_Info *server = p; >> > unsigned int pdu_length; >> > char *buf = NULL; >> > - struct task_struct *task_to_wake = NULL; >> > struct mid_q_entry *mid_entry; >> > >> > current->flags |= PF_MEMALLOC; >> > @@ -928,19 +927,7 @@ cifs_demultiplex_thread(void *p) >> > if (server->smallbuf) /* no sense logging a debug message if NULL */ >> > cifs_small_buf_release(server->smallbuf); >> > >> > - task_to_wake = xchg(&server->tsk, NULL); >> > clean_demultiplex_info(server); >> > - >> > - /* if server->tsk was NULL then wait for a signal before exiting */ >> > - if (!task_to_wake) { >> > - set_current_state(TASK_INTERRUPTIBLE); >> > - while (!signal_pending(current)) { >> > - schedule(); >> > - set_current_state(TASK_INTERRUPTIBLE); >> > - } >> > - set_current_state(TASK_RUNNING); >> > - } >> > - >> > module_put_and_exit(0); >> > } >> > >> > @@ -2061,8 +2048,6 @@ cifs_find_tcp_session(struct smb_vol *vol) >> > static void >> > cifs_put_tcp_session(struct TCP_Server_Info *server) >> > { >> > - struct task_struct *task; >> > - >> > spin_lock(&cifs_tcp_ses_lock); >> > if (--server->srv_count > 0) { >> > spin_unlock(&cifs_tcp_ses_lock); >> > @@ -2086,10 +2071,6 @@ cifs_put_tcp_session(struct TCP_Server_Info *server) >> > kfree(server->session_key.response); >> > server->session_key.response = NULL; >> > server->session_key.len = 0; >> > - >> > - task = xchg(&server->tsk, NULL); >> > - if (task) >> > - force_sig(SIGKILL, task); >> > } >> > >> > static struct TCP_Server_Info * >> >> Looks fine, I think. That code is a leftover from when we used a >> different scheme to take down the kthread and I don't think it's >> necessary any longer. >> >> Acked-by: Jeff Layton >> >> >> -- >> Thanks, >> >> Steve > -- Thanks, Steve -- Thanks, Steve