Messages in this thread Patch in this message | | | From | Atish Patra <> | Subject | [PATCH v2 1/4] RISC-V: Do not allocate memblock while iterating reserved memblocks | Date | Mon, 11 Jan 2021 15:45:01 -0800 |
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Currently, resource tree allocates memory blocks while iterating on the list. It leads to following kernel warning because memblock allocation also invokes memory block reservation API.
[ 0.000000] ------------[ cut here ]------------ [ 0.000000] WARNING: CPU: 0 PID: 0 at kernel/resource.c:795 __insert_resource+0x8e/0xd0 [ 0.000000] Modules linked in: [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 5.10.0-00022-ge20097fb37e2-dirty #549 [ 0.000000] epc: c00125c2 ra : c001262c sp : c1c01f50 [ 0.000000] gp : c1d456e0 tp : c1c0a980 t0 : ffffcf20 [ 0.000000] t1 : 00000000 t2 : 00000000 s0 : c1c01f60 [ 0.000000] s1 : ffffcf00 a0 : ffffff00 a1 : c1c0c0c4 [ 0.000000] a2 : 80c12b15 a3 : 80402000 a4 : 80402000 [ 0.000000] a5 : c1c0c0c4 a6 : 80c12b15 a7 : f5faf600 [ 0.000000] s2 : c1c0c0c4 s3 : c1c0e000 s4 : c1009a80 [ 0.000000] s5 : c1c0c000 s6 : c1d48000 s7 : c1613b4c [ 0.000000] s8 : 00000fff s9 : 80000200 s10: c1613b40 [ 0.000000] s11: 00000000 t3 : c1d4a000 t4 : ffffffff
This is also unnecessary as we can pre-compute the total memblocks required for each memory region and allocate it before the loop. It save precious boot time not going through memblock allocation code every time.
Fixes: 00ab027a3b82 ("RISC-V: Add kernel image sections to the resource tree")
Reviewed-by: Anup Patel <anup@brainfault.org> Tested-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Atish Patra <atish.patra@wdc.com> --- arch/riscv/kernel/setup.c | 24 +++++++++++++----------- 1 file changed, 13 insertions(+), 11 deletions(-)
diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c index 1d85e9bf783c..3fa3f26dde85 100644 --- a/arch/riscv/kernel/setup.c +++ b/arch/riscv/kernel/setup.c @@ -127,7 +127,9 @@ static void __init init_resources(void) { struct memblock_region *region = NULL; struct resource *res = NULL; - int ret = 0; + struct resource *mem_res = NULL; + size_t mem_res_sz = 0; + int ret = 0, i = 0; code_res.start = __pa_symbol(_text); code_res.end = __pa_symbol(_etext) - 1; @@ -145,16 +147,17 @@ static void __init init_resources(void) bss_res.end = __pa_symbol(__bss_stop) - 1; bss_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; + mem_res_sz = (memblock.memory.cnt + memblock.reserved.cnt) * sizeof(*mem_res); + mem_res = memblock_alloc(mem_res_sz, SMP_CACHE_BYTES); + if (!mem_res) + panic("%s: Failed to allocate %zu bytes\n", __func__, mem_res_sz); /* * Start by adding the reserved regions, if they overlap * with /memory regions, insert_resource later on will take * care of it. */ for_each_reserved_mem_region(region) { - res = memblock_alloc(sizeof(struct resource), SMP_CACHE_BYTES); - if (!res) - panic("%s: Failed to allocate %zu bytes\n", __func__, - sizeof(struct resource)); + res = &mem_res[i++]; res->name = "Reserved"; res->flags = IORESOURCE_MEM | IORESOURCE_BUSY; @@ -171,8 +174,10 @@ static void __init init_resources(void) * Ignore any other reserved regions within * system memory. */ - if (memblock_is_memory(res->start)) + if (memblock_is_memory(res->start)) { + memblock_free((phys_addr_t) res, sizeof(struct resource)); continue; + } ret = add_resource(&iomem_resource, res); if (ret < 0) @@ -181,10 +186,7 @@ static void __init init_resources(void) /* Add /memory regions to the resource tree */ for_each_mem_region(region) { - res = memblock_alloc(sizeof(struct resource), SMP_CACHE_BYTES); - if (!res) - panic("%s: Failed to allocate %zu bytes\n", __func__, - sizeof(struct resource)); + res = &mem_res[i++]; if (unlikely(memblock_is_nomap(region))) { res->name = "Reserved"; @@ -205,9 +207,9 @@ static void __init init_resources(void) return; error: - memblock_free((phys_addr_t) res, sizeof(struct resource)); /* Better an empty resource tree than an inconsistent one */ release_child_resources(&iomem_resource); + memblock_free((phys_addr_t) mem_res, mem_res_sz); } -- 2.25.1
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