From: Peter Zijlstra <peterz@infradead.org>
To: rjw@rjwysocki.net, oleg@redhat.com, mingo@kernel.org,
vincent.guittot@linaro.org, dietmar.eggemann@arm.com,
rostedt@goodmis.org, mgorman@suse.de,
Will Deacon <will@kernel.org>
Cc: linux-kernel@vger.kernel.org, peterz@infradead.org,
tj@kernel.org, linux-pm@vger.kernel.org
Subject: [PATCH v2 2/4] freezer,umh: Clean up freezer/initrd interaction
Date: Thu, 24 Jun 2021 11:21:58 +0200 [thread overview]
Message-ID: <20210624092615.885982587@infradead.org> (raw)
In-Reply-To: 20210624092156.332208049@infradead.org
handle_initrd() marks itself as PF_FREEZER_SKIP in order to ensure
that the UMH, which is going to freeze the system, doesn't
indefinitely wait for it's caller.
Rework things by adding UMH_FREEZABLE to indicate the completion is
freezable.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
include/linux/umh.h | 9 +++++----
init/do_mounts_initrd.c | 10 +---------
kernel/umh.c | 8 ++++++++
3 files changed, 14 insertions(+), 13 deletions(-)
--- a/include/linux/umh.h
+++ b/include/linux/umh.h
@@ -11,10 +11,11 @@
struct cred;
struct file;
-#define UMH_NO_WAIT 0 /* don't wait at all */
-#define UMH_WAIT_EXEC 1 /* wait for the exec, but not the process */
-#define UMH_WAIT_PROC 2 /* wait for the process to complete */
-#define UMH_KILLABLE 4 /* wait for EXEC/PROC killable */
+#define UMH_NO_WAIT 0x00 /* don't wait at all */
+#define UMH_WAIT_EXEC 0x01 /* wait for the exec, but not the process */
+#define UMH_WAIT_PROC 0x02 /* wait for the process to complete */
+#define UMH_KILLABLE 0x04 /* wait for EXEC/PROC killable */
+#define UMH_FREEZABLE 0x08 /* wait for EXEC/PROC freezable */
struct subprocess_info {
struct work_struct work;
--- a/init/do_mounts_initrd.c
+++ b/init/do_mounts_initrd.c
@@ -79,19 +79,11 @@ static void __init handle_initrd(void)
init_mkdir("/old", 0700);
init_chdir("/old");
- /*
- * In case that a resume from disk is carried out by linuxrc or one of
- * its children, we need to tell the freezer not to wait for us.
- */
- current->flags |= PF_FREEZER_SKIP;
-
info = call_usermodehelper_setup("/linuxrc", argv, envp_init,
GFP_KERNEL, init_linuxrc, NULL, NULL);
if (!info)
return;
- call_usermodehelper_exec(info, UMH_WAIT_PROC);
-
- current->flags &= ~PF_FREEZER_SKIP;
+ call_usermodehelper_exec(info, UMH_WAIT_PROC|UMH_FREEZABLE);
/* move initrd to rootfs' /old */
init_mount("..", ".", NULL, MS_MOVE, NULL);
--- a/kernel/umh.c
+++ b/kernel/umh.c
@@ -28,6 +28,7 @@
#include <linux/async.h>
#include <linux/uaccess.h>
#include <linux/initrd.h>
+#include <linux/freezer.h>
#include <trace/events/module.h>
@@ -436,6 +437,9 @@ int call_usermodehelper_exec(struct subp
if (wait == UMH_NO_WAIT) /* task has freed sub_info */
goto unlock;
+ if (wait & UMH_FREEZABLE)
+ freezer_do_not_count();
+
if (wait & UMH_KILLABLE) {
retval = wait_for_completion_killable(&done);
if (!retval)
@@ -448,6 +452,10 @@ int call_usermodehelper_exec(struct subp
}
wait_for_completion(&done);
+
+ if (wait & UMH_FREEZABLE)
+ freezer_count();
+
wait_done:
retval = sub_info->retval;
out:
next prev parent reply other threads:[~2021-06-24 9:28 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-24 9:21 [PATCH v2 0/4] Freezer rewrite Peter Zijlstra
2021-06-24 9:21 ` [PATCH v2 1/4] freezer: Have {,un}lock_system_sleep() save/restore flags Peter Zijlstra
2021-06-24 9:21 ` Peter Zijlstra [this message]
2021-06-24 9:21 ` [PATCH v2 3/4] ptrace: Track __TASK_TRACED state in p->ptrace Peter Zijlstra
2021-06-24 9:22 ` [PATCH v2 4/4] freezer,sched: Rewrite core freezer logic Peter Zijlstra
2021-07-07 14:14 ` Oleg Nesterov
2021-08-05 11:50 ` Peter Zijlstra
2021-06-30 17:05 ` [PATCH v2 0/4] Freezer rewrite Rafael J. Wysocki
2021-07-06 13:12 ` Peter Zijlstra
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