All of lore.kernel.org
 help / color / mirror / Atom feed
From: Mike Christie <michael.christie@oracle.com>
To: geert@linux-m68k.org, vverma@digitalocean.com, hdanton@sina.com,
	hch@infradead.org, stefanha@redhat.com, jasowang@redhat.com,
	mst@redhat.com, sgarzare@redhat.com,
	virtualization@lists.linux-foundation.org,
	christian.brauner@ubuntu.com, axboe@kernel.dk,
	linux-kernel@vger.kernel.org
Subject: [PATCH V6 05/10] signal: Perfom autoreap for PF_USER_WORKER
Date: Mon, 29 Nov 2021 13:47:02 -0600	[thread overview]
Message-ID: <20211129194707.5863-6-michael.christie@oracle.com> (raw)
In-Reply-To: <20211129194707.5863-1-michael.christie@oracle.com>

Userspace doesn't know about PF_USER_WORKER threads, so it can't do wait
to clean them up. For cases like where qemu will do dynamic/hot add/remove
of vhost devices, then we need to auto reap the thread like was done for
the kthread case, because qemu does not know what API the kernel/vhost
layer is using.

This has us do autoreaping for these threads similar to when the parent
ignores SIGCHLD and for kthreads.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
---
 kernel/signal.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/signal.c b/kernel/signal.c
index a629b11bf3e0..4ce2cc195269 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -2071,9 +2071,9 @@ bool do_notify_parent(struct task_struct *tsk, int sig)
 
 	psig = tsk->parent->sighand;
 	spin_lock_irqsave(&psig->siglock, flags);
-	if (!tsk->ptrace && sig == SIGCHLD &&
+	if (!tsk->ptrace && (tsk->flags & PF_USER_WORKER || (sig == SIGCHLD &&
 	    (psig->action[SIGCHLD-1].sa.sa_handler == SIG_IGN ||
-	     (psig->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT))) {
+	     (psig->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT))))) {
 		/*
 		 * We are exiting and our parent doesn't care.  POSIX.1
 		 * defines special semantics for setting SIGCHLD to SIG_IGN
-- 
2.25.1

_______________________________________________
Virtualization mailing list
Virtualization@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/virtualization

WARNING: multiple messages have this Message-ID (diff)
From: Mike Christie <michael.christie@oracle.com>
To: geert@linux-m68k.org, vverma@digitalocean.com, hdanton@sina.com,
	hch@infradead.org, stefanha@redhat.com, jasowang@redhat.com,
	mst@redhat.com, sgarzare@redhat.com,
	virtualization@lists.linux-foundation.org,
	christian.brauner@ubuntu.com, axboe@kernel.dk,
	linux-kernel@vger.kernel.org
Cc: Mike Christie <michael.christie@oracle.com>
Subject: [PATCH V6 05/10] signal: Perfom autoreap for PF_USER_WORKER
Date: Mon, 29 Nov 2021 13:47:02 -0600	[thread overview]
Message-ID: <20211129194707.5863-6-michael.christie@oracle.com> (raw)
In-Reply-To: <20211129194707.5863-1-michael.christie@oracle.com>

Userspace doesn't know about PF_USER_WORKER threads, so it can't do wait
to clean them up. For cases like where qemu will do dynamic/hot add/remove
of vhost devices, then we need to auto reap the thread like was done for
the kthread case, because qemu does not know what API the kernel/vhost
layer is using.

This has us do autoreaping for these threads similar to when the parent
ignores SIGCHLD and for kthreads.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
---
 kernel/signal.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/signal.c b/kernel/signal.c
index a629b11bf3e0..4ce2cc195269 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -2071,9 +2071,9 @@ bool do_notify_parent(struct task_struct *tsk, int sig)
 
 	psig = tsk->parent->sighand;
 	spin_lock_irqsave(&psig->siglock, flags);
-	if (!tsk->ptrace && sig == SIGCHLD &&
+	if (!tsk->ptrace && (tsk->flags & PF_USER_WORKER || (sig == SIGCHLD &&
 	    (psig->action[SIGCHLD-1].sa.sa_handler == SIG_IGN ||
-	     (psig->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT))) {
+	     (psig->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT))))) {
 		/*
 		 * We are exiting and our parent doesn't care.  POSIX.1
 		 * defines special semantics for setting SIGCHLD to SIG_IGN
-- 
2.25.1


  parent reply	other threads:[~2021-11-29 19:47 UTC|newest]

Thread overview: 57+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-11-29 19:46 [PATCH V6 01/10] Use copy_process in vhost layer Mike Christie
2021-11-29 19:46 ` Mike Christie
2021-11-29 19:46 ` [PATCH V6 01/10] fork: Make IO worker options flag based Mike Christie
2021-11-29 19:46   ` Mike Christie
2021-11-29 19:46 ` [PATCH V6 02/10] fork/vm: Move common PF_IO_WORKER behavior to new flag Mike Christie
2021-11-29 19:46   ` Mike Christie
2021-11-29 19:47 ` [PATCH V6 03/10] fork: add USER_WORKER flag to not dup/clone files Mike Christie
2021-11-29 19:47   ` Mike Christie
2021-11-29 19:47 ` [PATCH V6 04/10] fork: Add USER_WORKER flag to ignore signals Mike Christie
2021-11-29 19:47   ` Mike Christie
2021-11-29 19:47 ` Mike Christie [this message]
2021-11-29 19:47   ` [PATCH V6 05/10] signal: Perfom autoreap for PF_USER_WORKER Mike Christie
2021-12-17 18:42   ` Eric W. Biederman
2021-12-17 18:42     ` Eric W. Biederman
2021-11-29 19:47 ` [PATCH V6 06/10] fork: add helpers to clone a process for kernel use Mike Christie
2021-11-29 19:47   ` Mike Christie
2021-12-17 18:53   ` Eric W. Biederman
2021-12-17 18:53     ` Eric W. Biederman
2021-11-29 19:47 ` [PATCH V6 07/10] io_uring: switch to user_worker Mike Christie
2021-11-29 19:47   ` Mike Christie
2021-11-29 19:47 ` [PATCH V6 08/10] fork: remove create_io_thread Mike Christie
2021-11-29 19:47   ` Mike Christie
2021-11-29 19:47 ` [PATCH V6 09/10] vhost: move worker thread fields to new struct Mike Christie
2021-11-29 19:47   ` Mike Christie
2021-11-29 19:47 ` [PATCH V6 10/10] vhost: use user_worker to check RLIMITs Mike Christie
2021-11-29 19:47   ` Mike Christie
2021-12-17 19:01   ` Eric W. Biederman
2021-12-17 19:01     ` Eric W. Biederman
2021-12-08 20:34 ` [PATCH V6 01/10] Use copy_process in vhost layer Michael S. Tsirkin
2021-12-08 20:34   ` Michael S. Tsirkin
2021-12-08 22:13   ` michael.christie
2021-12-08 22:13     ` michael.christie
2021-12-09  9:32     ` Christian Brauner
2021-12-17 19:26 ` Eric W. Biederman
2021-12-17 19:26   ` Eric W. Biederman
2021-12-17 22:08   ` michael.christie
2021-12-17 22:08     ` michael.christie
2021-12-22  0:20     ` Eric W. Biederman
2021-12-22  0:20       ` Eric W. Biederman
2021-12-22 17:32       ` Mike Christie
2021-12-22 17:32         ` Mike Christie
2021-12-22 18:24         ` Eric W. Biederman
2021-12-22 18:24           ` Eric W. Biederman
2021-12-22 20:25           ` Michael S. Tsirkin
2021-12-22 20:25             ` Michael S. Tsirkin
2022-01-17 16:41           ` Mike Christie
2022-01-17 16:41             ` Mike Christie
2022-01-17 17:31             ` Eric W. Biederman
2022-01-17 17:31               ` Eric W. Biederman
2022-01-18 18:51               ` Mike Christie
2022-01-18 18:51                 ` Mike Christie
2022-01-18 19:00                 ` Mike Christie
2022-01-18 19:00                   ` Mike Christie
2022-01-18 19:12                 ` Eric W. Biederman
2022-01-18 19:12                   ` Eric W. Biederman
2022-02-02 21:02                   ` Mike Christie
2022-02-02 21:02                     ` Mike Christie

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20211129194707.5863-6-michael.christie@oracle.com \
    --to=michael.christie@oracle.com \
    --cc=axboe@kernel.dk \
    --cc=christian.brauner@ubuntu.com \
    --cc=geert@linux-m68k.org \
    --cc=hch@infradead.org \
    --cc=hdanton@sina.com \
    --cc=jasowang@redhat.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mst@redhat.com \
    --cc=sgarzare@redhat.com \
    --cc=stefanha@redhat.com \
    --cc=virtualization@lists.linux-foundation.org \
    --cc=vverma@digitalocean.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.