diff mbox series

[v2,14/17] x86/setup: simplify reserve_crashkernel()

Message ID 20200802163601.8189-15-rppt@kernel.org
State New
Headers show
Series memblock: seasonal cleaning^w cleanup | expand

Commit Message

Mike Rapoport Aug. 2, 2020, 4:35 p.m. UTC
From: Mike Rapoport <rppt@linux.ibm.com>

* Replace magic numbers with defines
* Replace memblock_find_in_range() + memblock_reserve() with
  memblock_phys_alloc_range()
* Stop checking for low memory size in reserve_crashkernel_low(). The
  allocation from limited range will anyway fail if there is no enough
  memory, so there is no need for extra traversal of memblock.memory

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
---
 arch/x86/kernel/setup.c | 40 ++++++++++++++--------------------------
 1 file changed, 14 insertions(+), 26 deletions(-)

Comments

Ingo Molnar Aug. 2, 2020, 6:02 p.m. UTC | #1
* Mike Rapoport <rppt@kernel.org> wrote:

> From: Mike Rapoport <rppt@linux.ibm.com>
> 
> * Replace magic numbers with defines
> * Replace memblock_find_in_range() + memblock_reserve() with
>   memblock_phys_alloc_range()
> * Stop checking for low memory size in reserve_crashkernel_low(). The
>   allocation from limited range will anyway fail if there is no enough
>   memory, so there is no need for extra traversal of memblock.memory
> 
> Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>

Assuming that this got or will get tested with a crash kernel:

Acked-by: Ingo Molnar <mingo@kernel.org>

Thanks,

	Ingo
Baoquan He Aug. 5, 2020, 6 a.m. UTC | #2
On 08/02/20 at 07:35pm, Mike Rapoport wrote:
> From: Mike Rapoport <rppt@linux.ibm.com>
> 
> * Replace magic numbers with defines
> * Replace memblock_find_in_range() + memblock_reserve() with
>   memblock_phys_alloc_range()
> * Stop checking for low memory size in reserve_crashkernel_low(). The
>   allocation from limited range will anyway fail if there is no enough
>   memory, so there is no need for extra traversal of memblock.memory
> 
> Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
> ---
>  arch/x86/kernel/setup.c | 40 ++++++++++++++--------------------------
>  1 file changed, 14 insertions(+), 26 deletions(-)

Applied this patch on top of 5.8, crashkernel reservation works well.
And the code change looks good.

Reviewed-by: Baoquan He <bhe@redhat.com>

> 
> diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
> index d8de4053c5e8..d7ced6982524 100644
> --- a/arch/x86/kernel/setup.c
> +++ b/arch/x86/kernel/setup.c
> @@ -419,13 +419,13 @@ static int __init reserve_crashkernel_low(void)
>  {
>  #ifdef CONFIG_X86_64
>  	unsigned long long base, low_base = 0, low_size = 0;
> -	unsigned long total_low_mem;
> +	unsigned long low_mem_limit;
>  	int ret;
>  
> -	total_low_mem = memblock_mem_size(1UL << (32 - PAGE_SHIFT));
> +	low_mem_limit = min(memblock_phys_mem_size(), CRASH_ADDR_LOW_MAX);
>  
>  	/* crashkernel=Y,low */
> -	ret = parse_crashkernel_low(boot_command_line, total_low_mem, &low_size, &base);
> +	ret = parse_crashkernel_low(boot_command_line, low_mem_limit, &low_size, &base);
>  	if (ret) {
>  		/*
>  		 * two parts from kernel/dma/swiotlb.c:
> @@ -443,23 +443,17 @@ static int __init reserve_crashkernel_low(void)
>  			return 0;
>  	}
>  
> -	low_base = memblock_find_in_range(0, 1ULL << 32, low_size, CRASH_ALIGN);
> +	low_base = memblock_phys_alloc_range(low_size, CRASH_ALIGN, 0, CRASH_ADDR_LOW_MAX);
>  	if (!low_base) {
>  		pr_err("Cannot reserve %ldMB crashkernel low memory, please try smaller size.\n",
>  		       (unsigned long)(low_size >> 20));
>  		return -ENOMEM;
>  	}
>  
> -	ret = memblock_reserve(low_base, low_size);
> -	if (ret) {
> -		pr_err("%s: Error reserving crashkernel low memblock.\n", __func__);
> -		return ret;
> -	}
> -
> -	pr_info("Reserving %ldMB of low memory at %ldMB for crashkernel (System low RAM: %ldMB)\n",
> +	pr_info("Reserving %ldMB of low memory at %ldMB for crashkernel (low RAM limit: %ldMB)\n",
>  		(unsigned long)(low_size >> 20),
>  		(unsigned long)(low_base >> 20),
> -		(unsigned long)(total_low_mem >> 20));
> +		(unsigned long)(low_mem_limit >> 20));
>  
>  	crashk_low_res.start = low_base;
>  	crashk_low_res.end   = low_base + low_size - 1;
> @@ -503,13 +497,13 @@ static void __init reserve_crashkernel(void)
>  		 * unless "crashkernel=size[KMG],high" is specified.
>  		 */
>  		if (!high)
> -			crash_base = memblock_find_in_range(CRASH_ALIGN,
> -						CRASH_ADDR_LOW_MAX,
> -						crash_size, CRASH_ALIGN);
> +			crash_base = memblock_phys_alloc_range(crash_size,
> +						CRASH_ALIGN, CRASH_ALIGN,
> +						CRASH_ADDR_LOW_MAX);
>  		if (!crash_base)
> -			crash_base = memblock_find_in_range(CRASH_ALIGN,
> -						CRASH_ADDR_HIGH_MAX,
> -						crash_size, CRASH_ALIGN);
> +			crash_base = memblock_phys_alloc_range(crash_size,
> +						CRASH_ALIGN, CRASH_ALIGN,
> +						CRASH_ADDR_HIGH_MAX);
>  		if (!crash_base) {
>  			pr_info("crashkernel reservation failed - No suitable area found.\n");
>  			return;
> @@ -517,19 +511,13 @@ static void __init reserve_crashkernel(void)
>  	} else {
>  		unsigned long long start;
>  
> -		start = memblock_find_in_range(crash_base,
> -					       crash_base + crash_size,
> -					       crash_size, 1 << 20);
> +		start = memblock_phys_alloc_range(crash_size, SZ_1M, crash_base,
> +						  crash_base + crash_size);
>  		if (start != crash_base) {
>  			pr_info("crashkernel reservation failed - memory is in use.\n");
>  			return;
>  		}
>  	}
> -	ret = memblock_reserve(crash_base, crash_size);
> -	if (ret) {
> -		pr_err("%s: Error reserving crashkernel memblock.\n", __func__);
> -		return;
> -	}
>  
>  	if (crash_base >= (1ULL << 32) && reserve_crashkernel_low()) {
>  		memblock_free(crash_base, crash_size);
> -- 
> 2.26.2
>
diff mbox series

Patch

diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index d8de4053c5e8..d7ced6982524 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -419,13 +419,13 @@  static int __init reserve_crashkernel_low(void)
 {
 #ifdef CONFIG_X86_64
 	unsigned long long base, low_base = 0, low_size = 0;
-	unsigned long total_low_mem;
+	unsigned long low_mem_limit;
 	int ret;
 
-	total_low_mem = memblock_mem_size(1UL << (32 - PAGE_SHIFT));
+	low_mem_limit = min(memblock_phys_mem_size(), CRASH_ADDR_LOW_MAX);
 
 	/* crashkernel=Y,low */
-	ret = parse_crashkernel_low(boot_command_line, total_low_mem, &low_size, &base);
+	ret = parse_crashkernel_low(boot_command_line, low_mem_limit, &low_size, &base);
 	if (ret) {
 		/*
 		 * two parts from kernel/dma/swiotlb.c:
@@ -443,23 +443,17 @@  static int __init reserve_crashkernel_low(void)
 			return 0;
 	}
 
-	low_base = memblock_find_in_range(0, 1ULL << 32, low_size, CRASH_ALIGN);
+	low_base = memblock_phys_alloc_range(low_size, CRASH_ALIGN, 0, CRASH_ADDR_LOW_MAX);
 	if (!low_base) {
 		pr_err("Cannot reserve %ldMB crashkernel low memory, please try smaller size.\n",
 		       (unsigned long)(low_size >> 20));
 		return -ENOMEM;
 	}
 
-	ret = memblock_reserve(low_base, low_size);
-	if (ret) {
-		pr_err("%s: Error reserving crashkernel low memblock.\n", __func__);
-		return ret;
-	}
-
-	pr_info("Reserving %ldMB of low memory at %ldMB for crashkernel (System low RAM: %ldMB)\n",
+	pr_info("Reserving %ldMB of low memory at %ldMB for crashkernel (low RAM limit: %ldMB)\n",
 		(unsigned long)(low_size >> 20),
 		(unsigned long)(low_base >> 20),
-		(unsigned long)(total_low_mem >> 20));
+		(unsigned long)(low_mem_limit >> 20));
 
 	crashk_low_res.start = low_base;
 	crashk_low_res.end   = low_base + low_size - 1;
@@ -503,13 +497,13 @@  static void __init reserve_crashkernel(void)
 		 * unless "crashkernel=size[KMG],high" is specified.
 		 */
 		if (!high)
-			crash_base = memblock_find_in_range(CRASH_ALIGN,
-						CRASH_ADDR_LOW_MAX,
-						crash_size, CRASH_ALIGN);
+			crash_base = memblock_phys_alloc_range(crash_size,
+						CRASH_ALIGN, CRASH_ALIGN,
+						CRASH_ADDR_LOW_MAX);
 		if (!crash_base)
-			crash_base = memblock_find_in_range(CRASH_ALIGN,
-						CRASH_ADDR_HIGH_MAX,
-						crash_size, CRASH_ALIGN);
+			crash_base = memblock_phys_alloc_range(crash_size,
+						CRASH_ALIGN, CRASH_ALIGN,
+						CRASH_ADDR_HIGH_MAX);
 		if (!crash_base) {
 			pr_info("crashkernel reservation failed - No suitable area found.\n");
 			return;
@@ -517,19 +511,13 @@  static void __init reserve_crashkernel(void)
 	} else {
 		unsigned long long start;
 
-		start = memblock_find_in_range(crash_base,
-					       crash_base + crash_size,
-					       crash_size, 1 << 20);
+		start = memblock_phys_alloc_range(crash_size, SZ_1M, crash_base,
+						  crash_base + crash_size);
 		if (start != crash_base) {
 			pr_info("crashkernel reservation failed - memory is in use.\n");
 			return;
 		}
 	}
-	ret = memblock_reserve(crash_base, crash_size);
-	if (ret) {
-		pr_err("%s: Error reserving crashkernel memblock.\n", __func__);
-		return;
-	}
 
 	if (crash_base >= (1ULL << 32) && reserve_crashkernel_low()) {
 		memblock_free(crash_base, crash_size);