From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pali =?utf-8?B?Um9ow6Fy?= Subject: Re: [PATCH v2 1/3] PM suspend/hibernate: Call notifier after freezing processes Date: Thu, 16 Jul 2015 09:33:02 +0200 Message-ID: <20150716073302.GA10393@pali> References: <1428254419-7334-1-git-send-email-pali.rohar@gmail.com> <1434885634-19895-1-git-send-email-pali.rohar@gmail.com> <1434885634-19895-2-git-send-email-pali.rohar@gmail.com> <3729395.1oJCgMXcLU@vostro.rjw.lan> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Content-Disposition: inline In-Reply-To: <3729395.1oJCgMXcLU@vostro.rjw.lan> Sender: linux-kernel-owner@vger.kernel.org To: "Rafael J. Wysocki" Cc: Alasdair Kergon , Mike Snitzer , Neil Brown , Len Brown , Pavel Machek , dm-devel@redhat.com, linux-raid@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org List-Id: linux-raid.ids On Thursday 16 July 2015 03:02:03 Rafael J. Wysocki wrote: > On Sunday, June 21, 2015 01:20:32 PM Pali Roh=C3=A1r wrote: > > To prevent race conditions on userspace processes with I/O some tak= s must be > > called after processes are freezed. This patch adds new events whic= h are > > delivered by pm_notifier_call_chain() after freezing processes when= doing > > suspend or hibernate action. > >=20 > > Signed-off-by: Pali Roh=C3=A1r > > --- > > include/linux/suspend.h | 2 ++ > > kernel/power/hibernate.c | 2 ++ > > kernel/power/suspend.c | 4 +++- > > 3 files changed, 7 insertions(+), 1 deletion(-) > >=20 > > diff --git a/include/linux/suspend.h b/include/linux/suspend.h > > index 5efe743..bc743c8 100644 > > --- a/include/linux/suspend.h > > +++ b/include/linux/suspend.h > > @@ -368,6 +368,8 @@ static inline bool hibernation_available(void) = { return false; } > > #define PM_POST_SUSPEND 0x0004 /* Suspend finished */ > > #define PM_RESTORE_PREPARE 0x0005 /* Going to restore a saved imag= e */ > > #define PM_POST_RESTORE 0x0006 /* Restore failed */ > > +#define PM_HIBERNATION_AFTER_FREEZE 0x0007 /* After hibernation fr= eeze */ > > +#define PM_SUSPEND_AFTER_FREEZE 0x0008 /* After suspend freeze */ > > =20 > > extern struct mutex pm_mutex; > > =20 > > diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c > > index 2329daa..184f7ee 100644 > > --- a/kernel/power/hibernate.c > > +++ b/kernel/power/hibernate.c > > @@ -671,6 +671,8 @@ int hibernate(void) > > if (error) > > goto Exit; > > =20 > > + pm_notifier_call_chain(PM_HIBERNATION_AFTER_FREEZE); >=20 > Don't we need to check errors from these? >=20 If yes, what to do in this case? Fail hibernation and goto Exit? > Also, if you're adding AFTER_FREEZE, it would be good to add BEFORE_T= HAW too > for symmetry. >=20 But there is no use case for BEFORE_THAW. At least it is not needed for= now. > > + > > lock_device_hotplug(); > > /* Allocate memory management structures */ > > error =3D create_basic_memory_bitmaps(); > > diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c > > index 8d7a1ef..ba2a945 100644 > > --- a/kernel/power/suspend.c > > +++ b/kernel/power/suspend.c > > @@ -277,8 +277,10 @@ static int suspend_prepare(suspend_state_t sta= te) > > trace_suspend_resume(TPS("freeze_processes"), 0, true); > > error =3D suspend_freeze_processes(); > > trace_suspend_resume(TPS("freeze_processes"), 0, false); > > - if (!error) > > + if (!error) { > > + pm_notifier_call_chain(PM_SUSPEND_AFTER_FREEZE); > > return 0; > > + } > > =20 > > suspend_stats.failed_freeze++; > > dpm_save_failed_step(SUSPEND_FREEZE); > >=20 >=20 --=20 Pali Roh=C3=A1r pali.rohar@gmail.com