Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753138Ab0AQAiV (ORCPT ); Sat, 16 Jan 2010 19:38:21 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753093Ab0AQAiV (ORCPT ); Sat, 16 Jan 2010 19:38:21 -0500 Received: from ogre.sisk.pl ([217.79.144.158]:39379 "EHLO ogre.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750823Ab0AQAiU (ORCPT ); Sat, 16 Jan 2010 19:38:20 -0500 From: "Rafael J. Wysocki" To: Maxim Levitsky Subject: [RFC][PATCH] PM: Force GFP_NOIO during suspend/resume (was: Re: [linux-pm] Memory allocations in .suspend became very unreliable) Date: Sun, 17 Jan 2010 01:38:37 +0100 User-Agent: KMail/1.12.3 (Linux/2.6.33-rc4-rjw; KDE/4.3.3; x86_64; ; ) Cc: linux-pm@lists.linux-foundation.org, LKML , "linux-mm" , Andrew Morton , Benjamin Herrenschmidt References: <1263549544.3112.10.camel@maxim-laptop> <1263678289.4276.4.camel@maxim-laptop> <201001162317.39940.rjw@sisk.pl> In-Reply-To: <201001162317.39940.rjw@sisk.pl> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <201001170138.37283.rjw@sisk.pl> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7501 Lines: 222 Hi, I thing the snippet below is a good summary of what this is about. On Saturday 16 January 2010, Rafael J. Wysocki wrote: > On Saturday 16 January 2010, Maxim Levitsky wrote: > > On Sat, 2010-01-16 at 01:57 +0100, Rafael J. Wysocki wrote: > > > On Saturday 16 January 2010, Maxim Levitsky wrote: > > > > On Fri, 2010-01-15 at 23:03 +0100, Rafael J. Wysocki wrote: > > > > > On Friday 15 January 2010, Maxim Levitsky wrote: > > > > > > Hi, > > > > > > > > > > Hi, > > > > > > > > > > > I know that this is very controversial, because here I want to describe > > > > > > a problem in a proprietary driver that happens now in 2.6.33-rc3 > > > > > > I am taking about nvidia driver. > > > > > > > > > > > > Some time ago I did very long hibernate test and found no errors after > > > > > > more that 200 cycles. > > > > > > > > > > > > Now I update to 2.6.33 and notice that system will hand when nvidia > > > > > > driver allocates memory is their .suspend functions. > > > > > > > > > > They shouldn't do that, there's no guarantee that's going to work at all. > > > > > > > > > > > This could fail in 2.6.32 if I would run many memory hungry > > > > > > applications, but now this happens with most of memory free. > > > > > > > > > > This sounds a little strange. What's the requested size of the image? > > > > Don't know, but system has to be very tight on memory. > > > > > > Can you send full dmesg, please? > > > > I deleted it, but for this case I think that hang was somewhere else. > > This task was hand on doing forking, which probably happened even before > > the freezer. > > > > Anyway, the problem is clear. Now __get_free_pages blocks more often, > > and can block in .suspend even if there is plenty of memory free. This is suspicious, but I leave it to the MM people for consideration. > > I now patched nvidia to use GFP_ATOMIC _always_, and problem disappear. > > It isn't such great solution when memory is tight though.... > > > > This is going to hit hard all nvidia users... > > Well, generally speaking, no driver should ever allocate memory using > GFP_KERNEL in its .suspend() routine, because that's not going to work, as you > can readily see. So this is a NVidia bug, hands down. > > Now having said that, we've been considering a change that will turn all > GFP_KERNEL allocations into GFP_NOIO during suspend/resume, so perhaps I'll > prepare a patch to do that and let's see what people think. If I didn't confuse anything (which is likely, because it's a bit late here now), the patch below should do the trick. I have only checked that it doesn't break compilation, so please take it with a grain of salt. Comments welcome. Rafael --- include/linux/gfp.h | 5 +++++ kernel/power/hibernate.c | 6 ++++++ kernel/power/main.c | 30 ++++++++++++++++++++++++++++++ kernel/power/power.h | 2 ++ kernel/power/suspend.c | 2 ++ 5 files changed, 45 insertions(+) Index: linux-2.6/include/linux/gfp.h =================================================================== --- linux-2.6.orig/include/linux/gfp.h +++ linux-2.6/include/linux/gfp.h @@ -342,4 +342,9 @@ static inline void set_gfp_allowed_mask( gfp_allowed_mask = mask; } +static inline gfp_t get_gfp_allowed_mask(void) +{ + return gfp_allowed_mask; +} + #endif /* __LINUX_GFP_H */ Index: linux-2.6/kernel/power/hibernate.c =================================================================== --- linux-2.6.orig/kernel/power/hibernate.c +++ linux-2.6/kernel/power/hibernate.c @@ -334,6 +334,7 @@ int hibernation_snapshot(int platform_mo goto Close; suspend_console(); + pm_force_noio_allocations(); error = dpm_suspend_start(PMSG_FREEZE); if (error) goto Recover_platform; @@ -351,6 +352,7 @@ int hibernation_snapshot(int platform_mo dpm_resume_end(in_suspend ? (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE); + pm_allow_io_allocations(); resume_console(); Close: platform_end(platform_mode); @@ -448,11 +450,13 @@ int hibernation_restore(int platform_mod pm_prepare_console(); suspend_console(); + pm_force_noio_allocations(); error = dpm_suspend_start(PMSG_QUIESCE); if (!error) { error = resume_target_kernel(platform_mode); dpm_resume_end(PMSG_RECOVER); } + pm_allow_io_allocations(); resume_console(); pm_restore_console(); return error; @@ -481,6 +485,7 @@ int hibernation_platform_enter(void) entering_platform_hibernation = true; suspend_console(); + pm_force_noio_allocations(); error = dpm_suspend_start(PMSG_HIBERNATE); if (error) { if (hibernation_ops->recover) @@ -518,6 +523,7 @@ int hibernation_platform_enter(void) Resume_devices: entering_platform_hibernation = false; dpm_resume_end(PMSG_RESTORE); + pm_allow_io_allocations(); resume_console(); Close: Index: linux-2.6/kernel/power/power.h =================================================================== --- linux-2.6.orig/kernel/power/power.h +++ linux-2.6/kernel/power/power.h @@ -187,6 +187,8 @@ static inline void suspend_test_finish(c #ifdef CONFIG_PM_SLEEP /* kernel/power/main.c */ extern int pm_notifier_call_chain(unsigned long val); +extern void pm_force_noio_allocations(void); +extern void pm_allow_io_allocations(void); #endif #ifdef CONFIG_HIGHMEM Index: linux-2.6/kernel/power/suspend.c =================================================================== --- linux-2.6.orig/kernel/power/suspend.c +++ linux-2.6/kernel/power/suspend.c @@ -208,6 +208,7 @@ int suspend_devices_and_enter(suspend_st goto Close; } suspend_console(); + pm_force_noio_allocations(); suspend_test_start(); error = dpm_suspend_start(PMSG_SUSPEND); if (error) { @@ -224,6 +225,7 @@ int suspend_devices_and_enter(suspend_st suspend_test_start(); dpm_resume_end(PMSG_RESUME); suspend_test_finish("resume devices"); + pm_allow_io_allocations(); resume_console(); Close: if (suspend_ops->end) Index: linux-2.6/kernel/power/main.c =================================================================== --- linux-2.6.orig/kernel/power/main.c +++ linux-2.6/kernel/power/main.c @@ -12,6 +12,7 @@ #include #include #include +#include #include "power.h" @@ -22,6 +23,35 @@ EXPORT_SYMBOL(pm_flags); #ifdef CONFIG_PM_SLEEP +static gfp_t saved_gfp_allowed_mask; + +/** + * pm_force_noio_allocations - Modify gfp_allowed_mask to disable IO allocations + * + * Change gfp_allowed_mask by unsetting __GFP_IO and __GFP_FS in it and save the + * old value. + */ +void pm_force_noio_allocations(void) +{ + saved_gfp_allowed_mask = get_gfp_allowed_mask(); + set_gfp_allowed_mask(saved_gfp_allowed_mask & ~(__GFP_IO | __GFP_FS)); +} + +/** + * pm_allow_io_allocations - Modify gfp_allowed_mask to allow IO allocations + * + * If the saved value of gfp_allowed_mask has __GFP_IO set, modify the current + * gfp_allowed_mask by setting this bit and anlogously for __GFP_FS. + */ +void pm_allow_io_allocations(void) +{ + gfp_t gfp_mask; + + gfp_mask = get_gfp_allowed_mask(); + gfp_mask |= saved_gfp_allowed_mask & (__GFP_IO | __GFP_FS); + set_gfp_allowed_mask(gfp_mask); +} + /* Routines for PM-transition notifications */ static BLOCKING_NOTIFIER_HEAD(pm_chain_head); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/