| Message ID | 20191107095611.18429-3-nsaenzjulienne@suse.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64: Fix CMA/crashkernel reservation | expand |
Hi Nicolas, On 11/7/19 4:56 AM, Nicolas Saenz Julienne wrote: > With the introduction of ZONE_DMA in arm64 we moved the default CMA and > crashkernel reservation into that area. This caused a regression on big > machines that need big CMA and crashkernel reservations. Note that > ZONE_DMA is only 1GB big. > > Restore the previous behavior as the wide majority of devices are OK > with reserving these in ZONE_DMA32. The ones that need them in ZONE_DMA > will configure it explicitly. > > Reported-by: Qian Cai <cai@lca.pw> > Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> > --- > arch/arm64/mm/init.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c > index 580d1052ac34..8385d3c0733f 100644 > --- a/arch/arm64/mm/init.c > +++ b/arch/arm64/mm/init.c > @@ -88,7 +88,7 @@ static void __init reserve_crashkernel(void) > > if (crash_base == 0) { > /* Current arm64 boot protocol requires 2MB alignment */ > - crash_base = memblock_find_in_range(0, ARCH_LOW_ADDRESS_LIMIT, > + crash_base = memblock_find_in_range(0, arm64_dma32_phys_limit, > crash_size, SZ_2M); > if (crash_base == 0) { > pr_warn("cannot allocate crashkernel (size:0x%llx)\n", > @@ -454,7 +454,7 @@ void __init arm64_memblock_init(void) > > high_memory = __va(memblock_end_of_DRAM() - 1) + 1; > > - dma_contiguous_reserve(arm64_dma_phys_limit ? : arm64_dma32_phys_limit); > + dma_contiguous_reserve(arm64_dma32_phys_limit); > } > > void __init bootmem_init(void) Can we get a bit more of a backstory about what the regression was on larger machines? If the 32-bit DMA region is too small, but the machine otherwise has plenty of memory, the crashkernel reservation will fail. Most e.g. enterprise users aren't going to respond to that situation by determining the placement manually, they'll just not have a crashkernel. Jon.
On 3/22/21 2:34 PM, Jon Masters wrote: > Hi Nicolas, > > On 11/7/19 4:56 AM, Nicolas Saenz Julienne wrote: >> With the introduction of ZONE_DMA in arm64 we moved the default CMA and >> crashkernel reservation into that area. This caused a regression on big >> machines that need big CMA and crashkernel reservations. Note that >> ZONE_DMA is only 1GB big. >> >> Restore the previous behavior as the wide majority of devices are OK >> with reserving these in ZONE_DMA32. The ones that need them in ZONE_DMA >> will configure it explicitly. >> >> Reported-by: Qian Cai <cai@lca.pw> >> Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> >> --- >> arch/arm64/mm/init.c | 4 ++-- >> 1 file changed, 2 insertions(+), 2 deletions(-) >> >> diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c >> index 580d1052ac34..8385d3c0733f 100644 >> --- a/arch/arm64/mm/init.c >> +++ b/arch/arm64/mm/init.c >> @@ -88,7 +88,7 @@ static void __init reserve_crashkernel(void) >> if (crash_base == 0) { >> /* Current arm64 boot protocol requires 2MB alignment */ >> - crash_base = memblock_find_in_range(0, ARCH_LOW_ADDRESS_LIMIT, >> + crash_base = memblock_find_in_range(0, arm64_dma32_phys_limit, >> crash_size, SZ_2M); >> if (crash_base == 0) { >> pr_warn("cannot allocate crashkernel (size:0x%llx)\n", >> @@ -454,7 +454,7 @@ void __init arm64_memblock_init(void) >> high_memory = __va(memblock_end_of_DRAM() - 1) + 1; >> - dma_contiguous_reserve(arm64_dma_phys_limit ? : >> arm64_dma32_phys_limit); >> + dma_contiguous_reserve(arm64_dma32_phys_limit); >> } >> void __init bootmem_init(void) > > Can we get a bit more of a backstory about what the regression was on > larger machines? If the 32-bit DMA region is too small, but the machine > otherwise has plenty of memory, the crashkernel reservation will fail. > Most e.g. enterprise users aren't going to respond to that situation by > determining the placement manually, they'll just not have a crashkernel. Nevermind, looks like Catalin already changed this logic in Jan 2021 by removing arm64_dma32_phys_limit and I'm out of date. Jon.
On Mon, 2021-03-22 at 14:40 -0400, Jon Masters wrote: > On 3/22/21 2:34 PM, Jon Masters wrote: > > Hi Nicolas, > > > > On 11/7/19 4:56 AM, Nicolas Saenz Julienne wrote: > > > With the introduction of ZONE_DMA in arm64 we moved the default CMA and > > > crashkernel reservation into that area. This caused a regression on big > > > machines that need big CMA and crashkernel reservations. Note that > > > ZONE_DMA is only 1GB big. > > > > > > Restore the previous behavior as the wide majority of devices are OK > > > with reserving these in ZONE_DMA32. The ones that need them in ZONE_DMA > > > will configure it explicitly. > > > > > > Reported-by: Qian Cai <cai@lca.pw> > > > Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> > > > --- > > > arch/arm64/mm/init.c | 4 ++-- > > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > > > diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c > > > index 580d1052ac34..8385d3c0733f 100644 > > > --- a/arch/arm64/mm/init.c > > > +++ b/arch/arm64/mm/init.c > > > @@ -88,7 +88,7 @@ static void __init reserve_crashkernel(void) > > > if (crash_base == 0) { > > > /* Current arm64 boot protocol requires 2MB alignment */ > > > - crash_base = memblock_find_in_range(0, ARCH_LOW_ADDRESS_LIMIT, > > > + crash_base = memblock_find_in_range(0, arm64_dma32_phys_limit, > > > crash_size, SZ_2M); > > > if (crash_base == 0) { > > > pr_warn("cannot allocate crashkernel (size:0x%llx)\n", > > > @@ -454,7 +454,7 @@ void __init arm64_memblock_init(void) > > > high_memory = __va(memblock_end_of_DRAM() - 1) + 1; > > > - dma_contiguous_reserve(arm64_dma_phys_limit ? : > > > arm64_dma32_phys_limit); > > > + dma_contiguous_reserve(arm64_dma32_phys_limit); > > > } > > > void __init bootmem_init(void) > > > > Can we get a bit more of a backstory about what the regression was on > > larger machines? If the 32-bit DMA region is too small, but the machine > > otherwise has plenty of memory, the crashkernel reservation will fail. > > Most e.g. enterprise users aren't going to respond to that situation by > > determining the placement manually, they'll just not have a crashkernel. > > Nevermind, looks like Catalin already changed this logic in Jan 2021 by > removing arm64_dma32_phys_limit and I'm out of date. Also see this series (already merged): https://lore.kernel.org/linux-arm-kernel/20201119175400.9995-1-nsaenzjulienne@suse.de/ Regads, Nicolas
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index 580d1052ac34..8385d3c0733f 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -88,7 +88,7 @@ static void __init reserve_crashkernel(void) if (crash_base == 0) { /* Current arm64 boot protocol requires 2MB alignment */ - crash_base = memblock_find_in_range(0, ARCH_LOW_ADDRESS_LIMIT, + crash_base = memblock_find_in_range(0, arm64_dma32_phys_limit, crash_size, SZ_2M); if (crash_base == 0) { pr_warn("cannot allocate crashkernel (size:0x%llx)\n", @@ -454,7 +454,7 @@ void __init arm64_memblock_init(void) high_memory = __va(memblock_end_of_DRAM() - 1) + 1; - dma_contiguous_reserve(arm64_dma_phys_limit ? : arm64_dma32_phys_limit); + dma_contiguous_reserve(arm64_dma32_phys_limit); } void __init bootmem_init(void)
With the introduction of ZONE_DMA in arm64 we moved the default CMA and crashkernel reservation into that area. This caused a regression on big machines that need big CMA and crashkernel reservations. Note that ZONE_DMA is only 1GB big. Restore the previous behavior as the wide majority of devices are OK with reserving these in ZONE_DMA32. The ones that need them in ZONE_DMA will configure it explicitly. Reported-by: Qian Cai <cai@lca.pw> Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> --- arch/arm64/mm/init.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)