Re: [PATCH RFC] ARM: mm: Fix for highmem on machines with more than 14 cores
On Mon, 24 Mar 2014, Anders Berg wrote: > The fixmap area was hard coded to 224 pages which was only enough for 14 > CPU:s. > Now the area adapts to the configured number of CPU:s (NR_CPUS). We still have > a hard limit of 30 CPU:s since we only have a single pte-chunk (512 pte:s). > > Signed-off-by: Anders Berg > Signed-off-by: Fredrik Markström This is under discussion already. Please have a look at this thread: http://news.gmane.org/group/gmane.linux.kernel/thread=1672068/ Nicolas
[PATCH RFC] ARM: mm: Fix for highmem on machines with more than 14 cores
Hi, While working of platform support for the LSI AXM5516 SoC (a 16 x A15 device) we ran into this limitation in fixmap.h where there is not enough room for the per-cpu pages if NR_CPUS is set to 16. The following patch avoids the overlap by lowering the base address according to the values of NR_CPUS and KM_TYPE_NR. Is this the way to handle this? Thanks, Anders Anders Berg (1): ARM: mm: Fix for highmem on machines with more than 14 cores arch/arm/include/asm/fixmap.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) -- 1.8.3.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH RFC] ARM: mm: Fix for highmem on machines with more than 14 cores
The fixmap area was hard coded to 224 pages which was only enough for 14 CPU:s. Now the area adapts to the configured number of CPU:s (NR_CPUS). We still have a hard limit of 30 CPU:s since we only have a single pte-chunk (512 pte:s). Signed-off-by: Anders Berg Signed-off-by: Fredrik Markström --- arch/arm/include/asm/fixmap.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/arm/include/asm/fixmap.h b/arch/arm/include/asm/fixmap.h index bbae919..40f1f05 100644 --- a/arch/arm/include/asm/fixmap.h +++ b/arch/arm/include/asm/fixmap.h @@ -7,15 +7,15 @@ * On ARM we already have well known fixed virtual addresses imposed by * the architecture such as the vector page which is located at 0x, * therefore a second level page table is already allocated covering - * 0xfff0 upwards. + * 0xffe0 upwards. * * The cache flushing code in proc-xscale.S uses the virtual area between * 0xfffe and 0xfffe. */ -#define FIXADDR_START 0xfff0UL +#define FIXADDR_SIZE ((KM_TYPE_NR * NR_CPUS) << PAGE_SHIFT) #define FIXADDR_TOP0xfffeUL -#define FIXADDR_SIZE (FIXADDR_TOP - FIXADDR_START) +#define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE) #define FIX_KMAP_BEGIN 0 #define FIX_KMAP_END (FIXADDR_SIZE >> PAGE_SHIFT) -- 1.8.3.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH RFC] ARM: mm: Fix for highmem on machines with more than 14 cores
The fixmap area was hard coded to 224 pages which was only enough for 14 CPU:s. Now the area adapts to the configured number of CPU:s (NR_CPUS). We still have a hard limit of 30 CPU:s since we only have a single pte-chunk (512 pte:s). Signed-off-by: Anders Berg anders.b...@lsi.com Signed-off-by: Fredrik Markström fredrik.markst...@gmail.com --- arch/arm/include/asm/fixmap.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/arm/include/asm/fixmap.h b/arch/arm/include/asm/fixmap.h index bbae919..40f1f05 100644 --- a/arch/arm/include/asm/fixmap.h +++ b/arch/arm/include/asm/fixmap.h @@ -7,15 +7,15 @@ * On ARM we already have well known fixed virtual addresses imposed by * the architecture such as the vector page which is located at 0x, * therefore a second level page table is already allocated covering - * 0xfff0 upwards. + * 0xffe0 upwards. * * The cache flushing code in proc-xscale.S uses the virtual area between * 0xfffe and 0xfffe. */ -#define FIXADDR_START 0xfff0UL +#define FIXADDR_SIZE ((KM_TYPE_NR * NR_CPUS) PAGE_SHIFT) #define FIXADDR_TOP0xfffeUL -#define FIXADDR_SIZE (FIXADDR_TOP - FIXADDR_START) +#define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE) #define FIX_KMAP_BEGIN 0 #define FIX_KMAP_END (FIXADDR_SIZE PAGE_SHIFT) -- 1.8.3.2 -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH RFC] ARM: mm: Fix for highmem on machines with more than 14 cores
Hi, While working of platform support for the LSI AXM5516 SoC (a 16 x A15 device) we ran into this limitation in fixmap.h where there is not enough room for the per-cpu pages if NR_CPUS is set to 16. The following patch avoids the overlap by lowering the base address according to the values of NR_CPUS and KM_TYPE_NR. Is this the way to handle this? Thanks, Anders Anders Berg (1): ARM: mm: Fix for highmem on machines with more than 14 cores arch/arm/include/asm/fixmap.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) -- 1.8.3.2 -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH RFC] ARM: mm: Fix for highmem on machines with more than 14 cores
On Mon, 24 Mar 2014, Anders Berg wrote: The fixmap area was hard coded to 224 pages which was only enough for 14 CPU:s. Now the area adapts to the configured number of CPU:s (NR_CPUS). We still have a hard limit of 30 CPU:s since we only have a single pte-chunk (512 pte:s). Signed-off-by: Anders Berg anders.b...@lsi.com Signed-off-by: Fredrik Markström fredrik.markst...@gmail.com This is under discussion already. Please have a look at this thread: http://news.gmane.org/group/gmane.linux.kernel/thread=1672068/ Nicolas
