diff mbox series

[v2,1/4] MIPS: Refactor early_parse_mem() to fix mem= parameter

Message ID 1646029866-6692-2-git-send-email-yangtiezhu@loongson.cn (mailing list archive)
State Superseded
Headers show
Series MIPS: Modify mem= and memmap= parameter | expand

Commit Message

Tiezhu Yang Feb. 28, 2022, 6:31 a.m. UTC
According to Documentation/admin-guide/kernel-parameters.txt,
the kernel command-line parameter mem= means "Force usage of
a specific amount of memory", but when add "mem=3G" to the
command-line, kernel boot hangs in sparse_init().

This commit is similar with the implementation of the other
archs such as arm64, powerpc and riscv, refactor the function
early_parse_mem() and then use memblock_enforce_memory_limit()
to limit the memory size.

With this patch, when add "mem=3G" to the command-line, the
kernel boots successfully, we can see the following messages:

  [    0.000000] Memory limited to 3072MB
  ...
  [    0.000000] Early memory node ranges
  [    0.000000]   node   0: [mem 0x0000000000200000-0x000000000effffff]
  [    0.000000]   node   0: [mem 0x0000000090200000-0x00000000ffffffff]
  [    0.000000]   node   0: [mem 0x0000000120000000-0x00000001613fffff]
  ...
  [    0.000000] Memory: 3005280K/3145728K available (...)

After login, the output of free command is consistent with the
above log.

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
---
 arch/mips/kernel/setup.c | 26 +++++++++-----------------
 1 file changed, 9 insertions(+), 17 deletions(-)

Comments

kernel test robot Feb. 28, 2022, 5:34 p.m. UTC | #1
Hi Tiezhu,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on hnaz-mm/master]
[also build test WARNING on linus/master v5.17-rc6 next-20220225]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Tiezhu-Yang/MIPS-Modify-mem-and-memmap-parameter/20220228-143251
base:   https://github.com/hnaz/linux-mm master
config: mips-allyesconfig (https://download.01.org/0day-ci/archive/20220228/202202281751.WKuGplhT-lkp@intel.com/config)
compiler: mips-linux-gcc (GCC) 11.2.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/0day-ci/linux/commit/ed304f835ff384c8fe9b788e13d3ec4d93878416
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Tiezhu-Yang/MIPS-Modify-mem-and-memmap-parameter/20220228-143251
        git checkout ed304f835ff384c8fe9b788e13d3ec4d93878416
        # save the config file to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross O=build_dir ARCH=mips SHELL=/bin/bash arch/mips/kernel/

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

   In file included from include/asm-generic/bug.h:22,
                    from arch/mips/include/asm/bug.h:42,
                    from include/linux/bug.h:5,
                    from include/linux/mmdebug.h:5,
                    from include/linux/mm.h:6,
                    from include/linux/memblock.h:12,
                    from arch/mips/kernel/setup.c:17:
   arch/mips/kernel/setup.c: In function 'early_parse_mem':
>> include/linux/kern_levels.h:5:25: warning: format '%lld' expects argument of type 'long long int', but argument 2 has type 'phys_addr_t' {aka 'unsigned int'} [-Wformat=]
       5 | #define KERN_SOH        "\001"          /* ASCII Start Of Header */
         |                         ^~~~~~
   include/linux/printk.h:418:25: note: in definition of macro 'printk_index_wrap'
     418 |                 _p_func(_fmt, ##__VA_ARGS__);                           \
         |                         ^~~~
   include/linux/printk.h:509:9: note: in expansion of macro 'printk'
     509 |         printk(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
         |         ^~~~~~
   include/linux/kern_levels.h:13:25: note: in expansion of macro 'KERN_SOH'
      13 | #define KERN_NOTICE     KERN_SOH "5"    /* normal but significant condition */
         |                         ^~~~~~~~
   include/linux/printk.h:509:16: note: in expansion of macro 'KERN_NOTICE'
     509 |         printk(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
         |                ^~~~~~~~~~~
   arch/mips/kernel/setup.c:350:9: note: in expansion of macro 'pr_notice'
     350 |         pr_notice("Memory limited to %lldMB\n", memory_limit >> 20);
         |         ^~~~~~~~~


vim +5 include/linux/kern_levels.h

314ba3520e513a Joe Perches 2012-07-30  4  
04d2c8c83d0e3a Joe Perches 2012-07-30 @5  #define KERN_SOH	"\001"		/* ASCII Start Of Header */
04d2c8c83d0e3a Joe Perches 2012-07-30  6  #define KERN_SOH_ASCII	'\001'
04d2c8c83d0e3a Joe Perches 2012-07-30  7  

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
diff mbox series

Patch

diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
index f979adf..6b6d718 100644
--- a/arch/mips/kernel/setup.c
+++ b/arch/mips/kernel/setup.c
@@ -339,27 +339,15 @@  static void __init bootmem_init(void)
 #endif	/* CONFIG_SGI_IP27 */
 
 static int usermem __initdata;
+static phys_addr_t memory_limit;
 
 static int __init early_parse_mem(char *p)
 {
-	phys_addr_t start, size;
-
-	/*
-	 * If a user specifies memory size, we
-	 * blow away any automatically generated
-	 * size.
-	 */
-	if (usermem == 0) {
-		usermem = 1;
-		memblock_remove(memblock_start_of_DRAM(),
-			memblock_end_of_DRAM() - memblock_start_of_DRAM());
-	}
-	start = 0;
-	size = memparse(p, &p);
-	if (*p == '@')
-		start = memparse(p + 1, &p);
+	if (!p)
+		return 1;
 
-	memblock_add(start, size);
+	memory_limit = memparse(p, &p) & PAGE_MASK;
+	pr_notice("Memory limited to %lldMB\n", memory_limit >> 20);
 
 	return 0;
 }
@@ -678,6 +666,10 @@  static void __init arch_mem_init(char **cmdline_p)
 	memblock_reserve(__pa_symbol(&__nosave_begin),
 		__pa_symbol(&__nosave_end) - __pa_symbol(&__nosave_begin));
 
+	/* Limit the memory. */
+	memblock_enforce_memory_limit(memory_limit);
+	memblock_allow_resize();
+
 	early_memtest(PFN_PHYS(ARCH_PFN_OFFSET), PFN_PHYS(max_low_pfn));
 }