[PATCH 5/5] kexec: X86: Pass memory ranges via e820 table instead of memmap= boot parameter

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Friday, April 12, 2013 08:24:12 AM Eric W. Biederman wrote:
> Thomas Renninger <trenn at suse.de> writes:
> > Currently ranges are passed via kernel boot parameters:
> > memmap=exactmap memmap=X#Y memmap=
> > 
> > Pass them via e820 table directly instead.
> 
> Reading through this code I am not seeing us mark areas of memory that
> we may not use as reserved.  Am I missing something?

They are added.
acpi and reserved (only like in the original kernel) come from
crash_memory_range[] array
(like in cmdline_add_memmap_acpi and  cmdline_add_memmap_reserved
and the free to use for crash kernel memory is coming from the array 
(memmap_p):
cmdline_add_memmap_acpi
I see that the merging function is not that nice to read, but I couldn't come 
up with something better for now.

In fact it should work exactly the same way as before with memmap= passing.
There is something odd with not passing the hightest e820 entry.
It seem to be needed, but it was not passed via memmap= as well?, so my 
version should also work and a test did:
The dumpfile is saved to /root/abuild/dumps/2013-04-15-12:59/vmcore
file size: 3251795465
free
             total       
Mem:      32633312

I answer more detailed on Yinghai's mail.

      Thomas
 
> Those areas need to be marked reserved or else the pci resource
> allocator in the kernel will think it is ok to put pci memory there.
> 
> Eric
> 
> > CC: Simon Horman <horms at verge.net.au>
> > CC: kexec at lists.infradead.org
> > CC: H. Peter Anvin <hpa at zytor.com>
> > CC: Eric W. Biederman <ebiederm at xmission.com>
> > CC: vgoyal at redhat.com
> > CC: yinghai at kernel.org
> > CC: cpw at sgi.com
> > 
> > Signed-off-by: Thomas Renninger <trenn at suse.de>
> > Signed-off-by: Thomas Renninger <Thomas Renninger" trenn at suse.de>
> > ---
> > 
> >  kexec/arch/i386/crashdump-x86.c   |  221
> >  ++++++++++++++++++------------------- kexec/arch/i386/x86-linux-setup.c
> >  |   11 ++-
> >  2 files changed, 116 insertions(+), 116 deletions(-)
> > 
> > diff --git a/kexec/arch/i386/crashdump-x86.c
> > b/kexec/arch/i386/crashdump-x86.c index f7821bc..8009efe 100644
> > --- a/kexec/arch/i386/crashdump-x86.c
> > +++ b/kexec/arch/i386/crashdump-x86.c
> > @@ -659,70 +659,6 @@ static void ultoa(unsigned long i, char *str)
> > 
> >  	}
> >  
> >  }
> > 
> > -static void cmdline_add_memmap_internal(char *cmdline, unsigned long
> > startk, -					unsigned long endk, int type)
> > -{
> > -	int cmdlen, len;
> > -	char str_mmap[256], str_tmp[20];
> > -
> > -	strcpy (str_mmap, " memmap=");
> > -	ultoa((endk-startk), str_tmp);
> > -	strcat (str_mmap, str_tmp);
> > -
> > -	if (type == RANGE_RAM)
> > -		strcat (str_mmap, "K@");
> > -	else if (type == RANGE_RESERVED)
> > -		strcat (str_mmap, "K$");
> > -	else if (type == RANGE_ACPI || type == RANGE_ACPI_NVS)
> > -		strcat (str_mmap, "K#");
> > -
> > -	ultoa(startk, str_tmp);
> > -	strcat (str_mmap, str_tmp);
> > -	strcat (str_mmap, "K");
> > -	len = strlen(str_mmap);
> > -	cmdlen = strlen(cmdline) + len;
> > -	if (cmdlen > (COMMAND_LINE_SIZE - 1))
> > -		die("Command line overflow\n");
> > -	strcat(cmdline, str_mmap);
> > -}
> > -
> > -/* Adds the appropriate memmap= options to command line, indicating the
> > - * memory regions the new kernel can use to boot into. */
> > -static int cmdline_add_memmap(char *cmdline, struct memory_range
> > *memmap_p) -{
> > -	int i, cmdlen, len;
> > -	unsigned long min_sizek = 100;
> > -	char str_mmap[256];
> > -
> > -	/* Exact map */
> > -	strcpy(str_mmap, " memmap=exactmap");
> > -	len = strlen(str_mmap);
> > -	cmdlen = strlen(cmdline) + len;
> > -	if (cmdlen > (COMMAND_LINE_SIZE - 1))
> > -		die("Command line overflow\n");
> > -	strcat(cmdline, str_mmap);
> > -
> > -	for (i = 0; i < CRASH_MAX_MEMMAP_NR;  i++) {
> > -		unsigned long startk, endk;
> > -		startk = (memmap_p[i].start/1024);
> > -		endk = ((memmap_p[i].end + 1)/1024);
> > -		if (!startk && !endk)
> > -			/* All regions traversed. */
> > -			break;
> > -
> > -		/* A region is not worth adding if region size < 100K. It eats
> > -		 * up precious command line length. */
> > -		if ((endk - startk) < min_sizek)
> > -			continue;
> > -		cmdline_add_memmap_internal(cmdline, startk, endk, RANGE_RAM);
> > -	}
> > -
> > -	dbgprintf("Command line after adding memmap\n");
> > -	dbgprintf("%s\n", cmdline);
> > -
> > -	return 0;
> > -}
> > -
> > 
> >  /* Adds the elfcorehdr= command line parameter to command line. */
> >  static int cmdline_add_elfcorehdr(char *cmdline, unsigned long addr)
> >  {
> > 
> > @@ -803,26 +739,6 @@ static enum coretype get_core_type(struct
> > crash_elf_info *elf_info,> 
> >  	}
> >  
> >  }
> > 
> > -/* Appends memmap=X#Y commandline for ACPI to command line*/
> > -static int cmdline_add_memmap_acpi(char *cmdline, unsigned long start,
> > -					unsigned long end)
> > -{
> > -	int align = 1024;
> > -	unsigned long startk, endk;
> > -
> > -	if (!(end - start))
> > -		return 0;
> > -
> > -	startk = start/1024;
> > -	endk = (end + align - 1)/1024;
> > -	cmdline_add_memmap_internal(cmdline, startk, endk, RANGE_ACPI);
> > -
> > -	dbgprintf("Command line after adding acpi memmap\n");
> > -	dbgprintf("%s\n", cmdline);
> > -
> > -	return 0;
> > -}
> > -
> > 
> >  /* Appends 'acpi_rsdp=' commandline for efi boot crash dump */
> >  static void cmdline_add_efi(char *cmdline)
> >  {
> > 
> > @@ -881,24 +797,101 @@ static void get_backup_area(struct kexec_info
> > *info,
> > 
> >  	info->backup_src_size = BACKUP_SRC_END - BACKUP_SRC_START + 1;
> >  
> >  }
> > 
> > -/* Appends memmap=X$Y commandline for reserved memory to command line*/
> > -static int cmdline_add_memmap_reserved(char *cmdline, unsigned long
> > start,
> > -					unsigned long end)
> > +/*
> > + * This function takes reserved (all kind of) memory from global
> > + * crash_memory_range[] memory ranges and takes memory the kdump/crash
> > + * kernel is allowed to use from the passed usable_mem memory ranges.
> > + * The passed usable_mem ranges are zero (!start && !end) terminated.
> > + *
> > + * The final memory map is again written into crash_memory_range[]
> > + * and intended to get passed as e820 table to the crash kernel
> > + */
> > +static int create_final_crash_map(struct memory_range *usable_mem)
> > 
> >  {
> > 
> > -	int align = 1024;
> > -	unsigned long startk, endk;
> > +	int i, m, c, tmp_map1_ranges, tmp_map2_ranges;
> > +	unsigned long min_sizek = 100;
> > +	/* crash_memory_map with usable memory ranges cut out */
> > +	struct memory_range tmp_map1[MAX_MEMORY_RANGES];
> > +	/* merge_map, but small ranges cut out */
> > +	struct memory_range tmp_map2[MAX_MEMORY_RANGES];
> > 
> > -	if (!(end - start))
> > -		return 0;
> > +	/*
> > +	 * Ignore usable memory ranges for kdump kernel smaller
> > +	 * than 100k to avoid too much ranges passed
> > +	 * Save the new ranges (exluding lower than 100k ranges) in tmp_map
> > +	 * and store the number of elements in tmp_map_ranges
> > +	 */
> > +	for (m = 0, i = 0; i < CRASH_MAX_MEMMAP_NR; i++) {
> > +		unsigned long startk, endk;
> > +		startk = (usable_mem[i].start/1024);
> > +		endk = ((usable_mem[i].end + 1)/1024);
> > +		if (!startk && !endk)
> > +			/* All regions traversed. */
> > +			break;
> > +
> > +		/* A region is not worth adding if region size < 100K. It eats
> > +		 * up precious command line length. */
> > +		if ((endk - startk) < min_sizek) {
> > +			dbgprintf("Removing: %luk - %luk\n", startk, endk);
> > +			continue;
> > +		} else {
> > +			tmp_map1[m].start = usable_mem[i].start;
> > +			tmp_map1[m].end   = usable_mem[i].end;
> > +			tmp_map1[m].type = usable_mem[i].type;
> > +			m++;
> > +		}
> > +	}
> > +	/* No need to check for !start && !end anymore */
> > +	tmp_map1_ranges = m;
> > 
> > -	startk = start/1024;
> > -	endk = (end + align - 1)/1024;
> > -	cmdline_add_memmap_internal(cmdline, startk, endk, RANGE_RESERVED);
> > +	for(i = 0; i < tmp_map1_ranges; ++i)
> > +		dbgprintf("%016Lx-%016Lx (%d)\n", tmp_map1[i].start,
> > +			  tmp_map1[i].end, tmp_map1[i].type);
> > +
> > +	/*
> > +	 * Cut out RANGE_RAM regions from crash_memory_ranges and store
> > +	 * them in tmp_map2_ranges
> > +	 */
> > +	for (c = 0, i = 0; i < crash_ranges; i++) {
> > +		if (crash_memory_range[i].type == RANGE_RAM)
> > +			continue;
> > +		tmp_map2[c].start = crash_memory_range[i].start;
> > +		tmp_map2[c].end = crash_memory_range[i].end;
> > +		tmp_map2[c].type = crash_memory_range[i].type;
> > +		c++;
> > +	}
> > +	tmp_map2_ranges = c;
> > +
> > +	/*
> > +	 * TBD: Check that no ranges overlap?
> > +	 * Can this happen at all?
> > +	 */
> > +	for (c = 0, m = 0, i = 0; i < MAX_MEMORY_RANGES; i++) {
> > +		if (m < tmp_map1_ranges &&
> > +		    (c >= tmp_map2_ranges ||
> > +		     tmp_map2[c].start > tmp_map1[m].start)) {
> > +			crash_memory_range[i].start = tmp_map1[m].start;
> > +			crash_memory_range[i].end   = tmp_map1[m].end;
> > +			crash_memory_range[i].type  = RANGE_RAM;
> > +			m++;
> > +			continue;
> > +		} else if (c < tmp_map2_ranges) {
> > +			crash_memory_range[i] = tmp_map2[c];
> > +			c++;
> > +			continue;
> > +		} else
> > +			break;
> > +	}
> > +	crash_ranges = i;
> > +
> > +	/*
> > +	 * End address has to be exlusive for e820 map
> > +	 * x        - 00010000
> > +	 * 00010000 - y
> > +	 */
> > +	for(i = 0; i < crash_ranges; ++i)
> > +		crash_memory_range[i].end++;
> > 
> > -#ifdef DEBUG
> > -		printf("Command line after adding reserved memmap\n");
> > -		printf("%s\n", cmdline);
> > -#endif
> > 
> >  	return 0;
> >  
> >  }
> > 
> > @@ -944,6 +937,12 @@ int load_crashdump_segments(struct kexec_info *info,
> > char* mod_cmdline,> 
> >  		return -1;
> >  	
> >  	}
> > 
> > +	/*
> > +	 * From now on the memory regions are stored in crash_memory_range[]
> > +	 * Currently the end address is inclusive at this point:
> > +	 * x        - 0000ffff
> > +	 * 00010000 - y
> > +	 */
> > 
> >  	if (xen_present()) {
> >  	
> >  		if (get_crash_memory_ranges_xen(&mem_range, &crash_ranges,
> >  		
> >  						elf_info.lowmem_limit) < 0)
> > 
> > @@ -971,7 +970,7 @@ int load_crashdump_segments(struct kexec_info *info,
> > char* mod_cmdline,> 
> >  	get_backup_area(info, mem_range, crash_ranges);
> > 
> > -	dbgprintf("CRASH MEMORY RANGES\n");
> > +	dbgprintf("TEMPORARY CRASH MEMORY RANGES\n");
> > 
> >  	for(i = 0; i < crash_ranges; ++i)
> >  	
> >  		dbgprintf("%016Lx-%016Lx (%d)\n", mem_range[i].start,
> > 
> > @@ -1063,24 +1062,18 @@ int load_crashdump_segments(struct kexec_info
> > *info, char* mod_cmdline,> 
> >  	dbgprintf("Created elf header segment at 0x%lx\n", elfcorehdr);
> >  	if (delete_memmap(memmap_p, elfcorehdr, memsz) < 0)
> >  	
> >  		return -1;
> > 
> > -	cmdline_add_memmap(mod_cmdline, memmap_p);
> > 
> >  	cmdline_add_efi(mod_cmdline);
> >  	cmdline_add_elfcorehdr(mod_cmdline, elfcorehdr);
> > 
> > -	/* Inform second kernel about the presence of ACPI tables. */
> > -	for (i = 0; i < MAX_MEMORY_RANGES; i++) {
> > -		unsigned long start, end;
> > -		if ( !( mem_range[i].type == RANGE_ACPI
> > -			|| mem_range[i].type == RANGE_ACPI_NVS
> > -			|| mem_range[i].type == RANGE_RESERVED) )
> > -			continue;
> > -		start = mem_range[i].start;
> > -		end = mem_range[i].end;
> > -		if (mem_range[i].type == RANGE_RESERVED)
> > -			cmdline_add_memmap_reserved(mod_cmdline, start, end);
> > -		else
> > -			cmdline_add_memmap_acpi(mod_cmdline, start, end);
> > -	}
> > +	/*
> > +	 * Redo crash_memory_range so that it can get passed as e820 info
> > +	 */
> > +	create_final_crash_map(memmap_p);
> > +
> > +	dbgprintf("FINAL CRASH MEMORY RANGES\n");
> > +	for(i = 0; i < crash_ranges; ++i)
> > +		dbgprintf("%016Lx-%016Lx (%d)\n", mem_range[i].start,
> > +			  mem_range[i].end, mem_range[i].type);
> > 
> >  	return 0;
> >  
> >  }
> > 
> > diff --git a/kexec/arch/i386/x86-linux-setup.c
> > b/kexec/arch/i386/x86-linux-setup.c index c538897..82b4bb9 100644
> > --- a/kexec/arch/i386/x86-linux-setup.c
> > +++ b/kexec/arch/i386/x86-linux-setup.c
> > @@ -505,8 +505,15 @@ void setup_linux_system_parameters(struct kexec_info
> > *info,> 
> >  	/* another safe default */
> >  	real_mode->aux_device_info = 0;
> > 
> > -	range = info->memory_range;
> > -	ranges = info->memory_ranges;
> > +	if (info->kexec_flags & KEXEC_ON_CRASH ||
> > +	    info->kexec_flags & KEXEC_PRESERVE_CONTEXT) {
> > +		range = crash_memory_range;
> > +		ranges = crash_ranges;
> > +	} else {
> > +		range = info->memory_range;
> > +		ranges = info->memory_ranges;
> > +	}
> > +
> > 
> >  	if (ranges > E820MAX) {
> >  	
> >  		if (!(info->kexec_flags & KEXEC_ON_CRASH))
> >  		
> >  			/*



[Index of Archives]     [LM Sensors]     [Linux Sound]     [ALSA Users]     [ALSA Devel]     [Linux Audio Users]     [Linux Media]     [Kernel]     [Gimp]     [Yosemite News]     [Linux Media]

  Powered by Linux