From eb33575cf67d3f35fa2510210ef92631266e2465 Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Wed, 13 May 2009 17:34:48 +0100 Subject: [ARM] Double check memmap is actually valid with a memmap has unexpected holes V2 pfn_valid() is meant to be able to tell if a given PFN has valid memmap associated with it or not. In FLATMEM, it is expected that holes always have valid memmap as long as there is valid PFNs either side of the hole. In SPARSEMEM, it is assumed that a valid section has a memmap for the entire section. However, ARM and maybe other embedded architectures in the future free memmap backing holes to save memory on the assumption the memmap is never used. The page_zone linkages are then broken even though pfn_valid() returns true. A walker of the full memmap must then do this additional check to ensure the memmap they are looking at is sane by making sure the zone and PFN linkages are still valid. This is expensive, but walkers of the full memmap are extremely rare. This was caught before for FLATMEM and hacked around but it hits again for SPARSEMEM because the page_zone linkages can look ok where the PFN linkages are totally screwed. This looks like a hatchet job but the reality is that any clean solution would end up consumning all the memory saved by punching these unexpected holes in the memmap. For example, we tried marking the memmap within the section invalid but the section size exceeds the size of the hole in most cases so pfn_valid() starts returning false where valid memmap exists. Shrinking the size of the section would increase memory consumption offsetting the gains. This patch identifies when an architecture is punching unexpected holes in the memmap that the memory model cannot automatically detect and sets ARCH_HAS_HOLES_MEMORYMODEL. At the moment, this is restricted to EP93xx which is the model sub-architecture this has been reported on but may expand later. When set, walkers of the full memmap must call memmap_valid_within() for each PFN and passing in what it expects the page and zone to be for that PFN. If it finds the linkages to be broken, it assumes the memmap is invalid for that PFN. Signed-off-by: Mel Gorman Signed-off-by: Russell King --- include/linux/mmzone.h | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) (limited to 'include') diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 186ec6ab334d..a47c879e1304 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -1097,6 +1097,32 @@ unsigned long __init node_memmap_size_bytes(int, unsigned long, unsigned long); #define pfn_valid_within(pfn) (1) #endif +#ifdef CONFIG_ARCH_HAS_HOLES_MEMORYMODEL +/* + * pfn_valid() is meant to be able to tell if a given PFN has valid memmap + * associated with it or not. In FLATMEM, it is expected that holes always + * have valid memmap as long as there is valid PFNs either side of the hole. + * In SPARSEMEM, it is assumed that a valid section has a memmap for the + * entire section. + * + * However, an ARM, and maybe other embedded architectures in the future + * free memmap backing holes to save memory on the assumption the memmap is + * never used. The page_zone linkages are then broken even though pfn_valid() + * returns true. A walker of the full memmap must then do this additional + * check to ensure the memmap they are looking at is sane by making sure + * the zone and PFN linkages are still valid. This is expensive, but walkers + * of the full memmap are extremely rare. + */ +int memmap_valid_within(unsigned long pfn, + struct page *page, struct zone *zone); +#else +static inline int memmap_valid_within(unsigned long pfn, + struct page *page, struct zone *zone) +{ + return 1; +} +#endif /* CONFIG_ARCH_HAS_HOLES_MEMORYMODEL */ + #endif /* !__GENERATING_BOUNDS.H */ #endif /* !__ASSEMBLY__ */ #endif /* _LINUX_MMZONE_H */ -- cgit v1.2.3 From 03fbdb15c14e9746c63168e3ff2c64b9c8336d33 Mon Sep 17 00:00:00 2001 From: Alessandro Rubini Date: Wed, 20 May 2009 22:39:08 +0100 Subject: [ARM] 5519/1: amba probe: pass "struct amba_id *" instead of void * The second argument of the probe method points to the amba_id structure, so it's better passed with the correct type. None of the current in-tree drivers uses the pointer, so they have only been checked for a clean compile. Change suggested by Russell King. Signed-off-by: Alessandro Rubini Signed-off-by: Russell King --- drivers/input/serio/ambakmi.c | 2 +- drivers/mmc/host/mmci.c | 2 +- drivers/rtc/rtc-pl030.c | 2 +- drivers/rtc/rtc-pl031.c | 2 +- drivers/serial/amba-pl010.c | 2 +- drivers/serial/amba-pl011.c | 2 +- drivers/video/amba-clcd.c | 2 +- include/linux/amba/bus.h | 2 +- sound/arm/aaci.c | 2 +- 9 files changed, 9 insertions(+), 9 deletions(-) (limited to 'include') diff --git a/drivers/input/serio/ambakmi.c b/drivers/input/serio/ambakmi.c index e29cdc13a199..a28c06d686e1 100644 --- a/drivers/input/serio/ambakmi.c +++ b/drivers/input/serio/ambakmi.c @@ -107,7 +107,7 @@ static void amba_kmi_close(struct serio *io) clk_disable(kmi->clk); } -static int amba_kmi_probe(struct amba_device *dev, void *id) +static int amba_kmi_probe(struct amba_device *dev, struct amba_id *id) { struct amba_kmi_port *kmi; struct serio *io; diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c index 36875dcfa492..7d4febdab286 100644 --- a/drivers/mmc/host/mmci.c +++ b/drivers/mmc/host/mmci.c @@ -490,7 +490,7 @@ static void mmci_check_status(unsigned long data) mod_timer(&host->timer, jiffies + HZ); } -static int __devinit mmci_probe(struct amba_device *dev, void *id) +static int __devinit mmci_probe(struct amba_device *dev, struct amba_id *id) { struct mmc_platform_data *plat = dev->dev.platform_data; struct mmci_host *host; diff --git a/drivers/rtc/rtc-pl030.c b/drivers/rtc/rtc-pl030.c index 826153552157..aaf1f75fa293 100644 --- a/drivers/rtc/rtc-pl030.c +++ b/drivers/rtc/rtc-pl030.c @@ -102,7 +102,7 @@ static const struct rtc_class_ops pl030_ops = { .set_alarm = pl030_set_alarm, }; -static int pl030_probe(struct amba_device *dev, void *id) +static int pl030_probe(struct amba_device *dev, struct amba_id *id) { struct pl030_rtc *rtc; int ret; diff --git a/drivers/rtc/rtc-pl031.c b/drivers/rtc/rtc-pl031.c index 333eec689d2f..451fc13784d1 100644 --- a/drivers/rtc/rtc-pl031.c +++ b/drivers/rtc/rtc-pl031.c @@ -127,7 +127,7 @@ static int pl031_remove(struct amba_device *adev) return 0; } -static int pl031_probe(struct amba_device *adev, void *id) +static int pl031_probe(struct amba_device *adev, struct amba_id *id) { int ret; struct pl031_local *ldata; diff --git a/drivers/serial/amba-pl010.c b/drivers/serial/amba-pl010.c index e3a5ad5ef1d6..cdc049d4350f 100644 --- a/drivers/serial/amba-pl010.c +++ b/drivers/serial/amba-pl010.c @@ -665,7 +665,7 @@ static struct uart_driver amba_reg = { .cons = AMBA_CONSOLE, }; -static int pl010_probe(struct amba_device *dev, void *id) +static int pl010_probe(struct amba_device *dev, struct amba_id *id) { struct uart_amba_port *uap; void __iomem *base; diff --git a/drivers/serial/amba-pl011.c b/drivers/serial/amba-pl011.c index 8b2b9700f3e4..88fdac51b6c5 100644 --- a/drivers/serial/amba-pl011.c +++ b/drivers/serial/amba-pl011.c @@ -729,7 +729,7 @@ static struct uart_driver amba_reg = { .cons = AMBA_CONSOLE, }; -static int pl011_probe(struct amba_device *dev, void *id) +static int pl011_probe(struct amba_device *dev, struct amba_id *id) { struct uart_amba_port *uap; void __iomem *base; diff --git a/drivers/video/amba-clcd.c b/drivers/video/amba-clcd.c index 61050ab14128..d1f80bac54f0 100644 --- a/drivers/video/amba-clcd.c +++ b/drivers/video/amba-clcd.c @@ -437,7 +437,7 @@ static int clcdfb_register(struct clcd_fb *fb) return ret; } -static int clcdfb_probe(struct amba_device *dev, void *id) +static int clcdfb_probe(struct amba_device *dev, struct amba_id *id) { struct clcd_board *board = dev->dev.platform_data; struct clcd_fb *fb; diff --git a/include/linux/amba/bus.h b/include/linux/amba/bus.h index 51e6e54b2aa1..9b93cafa82a0 100644 --- a/include/linux/amba/bus.h +++ b/include/linux/amba/bus.h @@ -28,7 +28,7 @@ struct amba_id { struct amba_driver { struct device_driver drv; - int (*probe)(struct amba_device *, void *); + int (*probe)(struct amba_device *, struct amba_id *); int (*remove)(struct amba_device *); void (*shutdown)(struct amba_device *); int (*suspend)(struct amba_device *, pm_message_t); diff --git a/sound/arm/aaci.c b/sound/arm/aaci.c index 7fbd68fab944..5c48e36038f2 100644 --- a/sound/arm/aaci.c +++ b/sound/arm/aaci.c @@ -1074,7 +1074,7 @@ static unsigned int __devinit aaci_size_fifo(struct aaci *aaci) return i; } -static int __devinit aaci_probe(struct amba_device *dev, void *id) +static int __devinit aaci_probe(struct amba_device *dev, struct amba_id *id) { struct aaci *aaci; int ret, i; -- cgit v1.2.3