在 2018年12月17日 21:00, Borislav Petkov 写道: > On Sun, Dec 16, 2018 at 09:16:16PM +0800, Lianbo Jiang wrote: >> +clear_idx >> +========= >> +The index that the next printk record to read after the last 'clear' >> +command. It indicates the first record after the last SYSLOG_ACTION >> +_CLEAR, like issued by 'dmesg -c'. > > What is that used for by the userspace tools? > The clear_idx is used when dumping the dmesg log. >> + >> +log_next_idx >> +============ >> +The index of the next record to store in the buffer 'log_buf'. It helps >> +to compute the index of current strings position. >> + >> +printk_log >> +========== >> +The size of a structure 'printk_log'. It helps to compute the size of >> +messages, and extract dmesg log. > > What is the difference between that and log_buf? > The printk_log is used to output human readable text, it will encapsulate header information for log_buf, such as timestamp, syslog level, etc. > > >> + >> +(printk_log, ts_nsec|len|text_len|dict_len) >> +=========================================== >> +It represents these field offsets in the structure 'printk_log'. User >> +space tools can parse it and detect any changes to structure down the >> +line. > > What does that mean? "any changes down the line"? > User space tools can parse it and check whether the values of printk_log's members have been changed. I will improve it in patch v4. >> + >> +(free_area.free_list, MIGRATE_TYPES) >> +==================================== >> +The number of migrate types for pages. The free_list is divided into >> +the array, it needs to know the number of the array. > > ... for? > It needs to know the number of the array when makedumpfile computes the number of free pages. >> + >> +NR_FREE_PAGES >> +============= >> +On linux-2.6.21 or later, the number of free_pages is in >> +vm_stat[NR_FREE_PAGES]. It can get the number of free pages from the >> +array. >> + >> +PG_lru|PG_private|PG_swapcache|PG_swapbacked|PG_slab| >> +PG_hwpoision|PG_head_mask >> +===================================================== >> +It means the attribute of a page. These flags will be used to filter >> +the free pages. >> + >> +PAGE_BUDDY_MAPCOUNT_VALUE or ~PG_buddy >> +====================================== >> +The 'PG_buddy' flag indicates that the page is free and in the buddy >> +system. Makedumpfile can exclude the free pages managed by a buddy. > > That text belongs with the one above? > It exported the value of (~PG_buddy), so it is placed here independently. >> + >> +HUGETLB_PAGE_DTOR >> +================= >> +The 'HUGETLB_PAGE_DTOR' flag indicates the hugetlbfs pages. Makedumpfile >> +will exclude these pages. >> + >> +================ >> +x86_64 variables >> +================ >> + >> +phys_base >> +========= >> +In x86_64, the 'phys_base' is necessary to convert virtual address of >> +exported kernel symbol to physical address. >> + >> +init_top_pgt >> +============ >> +The 'init_top_pgt' used to walk through the whole page table and convert >> +virtual address to physical address. > > This is the same as swapper_pg_dir? > These two variables are somewhat similar, but they are used in different scenarios. >> + >> +pgtable_l5_enabled >> +================== >> +User-space tools need to know whether the crash kernel was in 5-level >> +paging mode or not. >> + >> +node_data >> +========= >> +This is a struct 'pglist_data' array, it stores all numa nodes information. >> +In general, Makedumpfile can get the pglist_data structure from symbol >> +'node_data'. >> + >> +(node_data, MAX_NUMNODES) >> +========================= >> +The number of this 'node_data' array. It means the maximum number of the >> +nodes in system. >> + >> +KERNELOFFSET >> +============ >> +Randomize the address of the kernel image. This is the offset of KASLR in >> +VMCOREINFO ELF notes. It is used to compute the page offset in x86_64. If >> +KASLE is disabled, this value is zero. >> + >> +KERNEL_IMAGE_SIZE >> +================= >> +The size of 'KERNEL_IMAGE_SIZE', currently unused. > > So remove? > I'm not sure whether it should be removed, so i keep it. >> + >> +The old MODULES_VADDR need be decided by KERNEL_IMAGE_SIZE when kaslr >> +enabled. Now MODULES_VADDR is not needed any more since Pratyush makes >> +all VA to PA converting done by page table lookup. > > Also, I did clean this up considerably - please include in your next > version: > Great, thanks for you help. I will post v4 later. Regards, Lianbo > --- > diff --git a/Documentation/kdump/vmcoreinfo.txt b/Documentation/kdump/vmcoreinfo.txt > index d71260bf383a..2ce34d952bfd 100644 > --- a/Documentation/kdump/vmcoreinfo.txt > +++ b/Documentation/kdump/vmcoreinfo.txt > @@ -1,18 +1,19 @@ > ================================================================ > - Documentation for VMCOREINFO > + VMCOREINFO > ================================================================ > > ======================= > What is the VMCOREINFO? > ======================= > -It is a special ELF note section. The VMCOREINFO contains the first > -kernel's various information, for example, structure size, page size, > -symbol values and field offset, etc. These data are packed into an ELF > -note section, and these data will also help user-space tools(e.g. crash > -makedumpfile) analyze the first kernel's memory usage. > - > -In general, makedumpfile can dump the VMCOREINFO contents from vmlinux > -in the first kernel. For example: > + > +VMCOREINFO is a special ELF note section. It contains various > +information from the kernel like structure size, page size, symbol > +values, field offsets, etc. These data are packed into an ELF note > +section and used by user-space tools like crash and makedumpfile to > +analyze a kernel's memory layout. > + > +To dump the VMCOREINFO contents, one can do: > + > # makedumpfile -g VMCOREINFO -x vmlinux > > ================ > @@ -20,123 +21,132 @@ Common variables > ================ > > init_uts_ns.name.release > -======================== > -The number of OS release. Based on this version number, people can find > -the source code for the corresponding version. When analyzing the vmcore, > -people must read the source code to find the reason why the kernel crashed. > +------------------------ > + > +The version of the Linux kernel. Used to find the corresponding source > +code from which the kernel has been built. > > PAGE_SIZE > -========= > -The size of a page. It is the smallest unit of data for memory management > -in kernel. It is usually 4k bytes and the page is aligned in 4k bytes, > -which is very important for computing address. > +--------- > + > +The size of a page. It is the smallest unit of data for memory > +management in kernel. It is usually 4096 bytes and a page is aligned on > +4096 bytes. Used for computing page addresses. > > init_uts_ns > -=========== > -This is the UTS namespace, which is used to isolate two specific elements > -of the system that relate to the uname system call. The UTS namespace is > -named after the data structure used to store information returned by the > -uname system call. > +----------- > + > +This is the UTS namespace, which is used to isolate two specific > +elements of the system that relate to the uname(2) system call. The UTS > +namespace is named after the data structure used to store information > +returned by the uname(2) system call. > > -User-space tools can get the kernel name, host name, kernel release number, > -kernel version, architecture name and OS type from the 'init_uts_ns'. > +User-space tools can get the kernel name, host name, kernel release > +number, kernel version, architecture name and OS type from it. > > node_online_map > -=============== > -It is a macro definition, actually it is an array node_states[N_ONLINE], > -and it represents the set of online node in a system, one bit position > -per node number. > +--------------- > > -This is used to keep track of which nodes are in the system and online. > +An array node_states[N_ONLINE] which represents the set of online node > +in a system, one bit position per node number. Used to keep track of > +which nodes are in the system and online. > > swapper_pg_dir > -============= > -It generally indicates the pgd for the kernel. When mmu is enabled in > -config file, the 'swapper_pg_dir' is valid. > +------------- > > -The 'swapper_pg_dir' helps to translate the virtual address to a physical > -address. > +The global page directory pointer of the kernel. Used to translate > +virtual to physical addresses. > > _stext > -====== > -It is an assemble symbol that defines the beginning of the text section. > -In general, the '_stext' indicates the kernel start address. This is used > -to convert a virtual address to a physical address when the virtual address > -does not belong to the 'vmalloc' address. > +------ > + > +Defines the beginning of the text section. In general, _stext indicates > +the kernel start address. Used to convert a virtual address from the > +direct kernel map to a physical address. > > vmap_area_list > -============== > -It stores the virtual area list, makedumpfile can get the vmalloc start > +-------------- > + > +Stores the virtual area list. makedumpfile can get the vmalloc start > value from this variable. This value is necessary for vmalloc translation. > > mem_map > -======= > -Physical addresses are translated to struct pages by treating them as an > -index into the mem_map array. Shifting a physical address PAGE_SHIFT bits > -to the right will treat it as a PFN from physical address 0, which is also > -an index within the mem_map array. > +------- > + > +Physical addresses are translated to struct pages by treating them as > +an index into the mem_map array. Right-shifting a physical address > +PAGE_SHIFT bits converts it into a page frame number which is an index > +into that mem_map array. > > -In short, it can map the address to struct page. > +Used to map an address to the corresponding struct page. > > contig_page_data > -================ > -Makedumpfile can get the pglist_data structure from this symbol > -'contig_page_data'. The pglist_data structure is used to describe the > -memory layout. > +---------------- > > -User-space tools can use this symbols for excluding free pages. > +Makedumpfile can get the pglist_data structure from this symbol, which > +is used to describe the memory layout. > + > +User-space tools use this to exclude free pages when dumping memory. > > mem_section|(mem_section, NR_SECTION_ROOTS)|(mem_section, section_mem_map) > -========================================================================== > -Export the address of 'mem_section' array, and it's length, structure size, > -and the 'section_mem_map' offset. > +-------------------------------------------------------------------------- > + > +The address of the mem_section array, its length, structure size, and > +the section_mem_map offset. > > It exists in the sparse memory mapping model, and it is also somewhat > -similar to the mem_map variable, both of them will help to translate > -the address. > +similar to the mem_map variable, both of them are used to translate an > +address. > > page > -==== > -The size of a 'page' structure. In kernel, the page is an important data > -structure, it is widely used to compute the continuous memory. > +---- > + > +The size of a page structure. struct page is an important data structure > +and it is widely used to compute the contiguous memory. > > pglist_data > -=========== > -The size of a 'pglist_data' structure. This value will be used to check if > -the 'pglist_data' structure is valid. It is also one of the conditions for > -checking the memory type. > +----------- > + > +The size of a pglist_data structure. This value will be used to check > +if the pglist_data structure is valid. It is also used for checking the > +memory type. > > zone > -==== > -The size of a 'zone' structure. This value is often used to check if the > -'zone' structure is found. It is necessary structures for excluding free > -pages. > +---- > + > +The size of a zone structure. This value is often used to check if the > +zone structure has been found. It is also used for excluding free pages. > > free_area > -========= > -The size of a 'free_area' structure. It indicates whether the 'free_area' > -structure is valid or not. This is useful for excluding free pages. > +--------- > + > +The size of a free_area structure. It indicates whether the free_area > +structure is valid or not. Useful for excluding free pages. > > list_head > -========= > -The size of a 'list_head' structure. It depends on this value when > -iterating the free list. > +--------- > + > +The size of a list_head structure. Used when iterating lists in a > +post-mortem analysis session. > > nodemask_t > -========== > -The size of a 'nodemask_t' type. This value is used to compute the number > +---------- > + > +The size of a nodemask_t type. This value is used to compute the number > of online nodes. > > (page, flags|_refcount|mapping|lru|_mapcount|private|compound_dtor| > compound_order|compound_head) > -=================================================================== > +------------------------------------------------------------------- > + > User-space tools can compute their values based on the offset of these > variables. The variables are helpful to exclude unnecessary pages. > > (pglist_data, node_zones|nr_zones|node_mem_map|node_start_pfn|node_ > spanned_pages|node_id) > -=================================================================== > -On NUMA machines, each NUMA node has a pg_data_t to describe it's memory > +------------------------------------------------------------------- > + > +On NUMA machines, each NUMA node has a pg_data_t to describe its memory > layout. On UMA machines there is a single pglist_data which describes the > whole memory. > > @@ -144,16 +154,18 @@ These values are used to check the memory type, and they are also helpful > to compute the virtual address for memory map. > > (zone, free_area|vm_stat|spanned_pages) > -======================================= > -Each node is divided up into a number of blocks called zones which > +--------------------------------------- > + > +Each node is divided into a number of blocks called zones which > represent ranges within memory. A zone is described by a structure zone. > Each zone type is suitable for a different type of usage. > > -User-space tools can compute their values based on the offset of these > +User-space tools can compute required values based on the offset of these > variables. > > (free_area, free_list) > -====================== > +---------------------- > + > Offset of the free_list's member. This value is used to compute the number > of free pages. > > @@ -162,295 +174,325 @@ The fields in this structure are simple, the free_list represents a linked > list of free page blocks. > > (list_head, next|prev) > -====================== > -Offsets of the list_head's members. In general, the list_head is used to > -define a circular linked list. User-space tools often need to traverse > -the lists to get specific pages. > +---------------------- > + > +Offsets of the list_head's members. list_head is used to define a > +circular linked list. User-space tools need these in order to traverse > +lists. > > (vmap_area, va_start|list) > -========================== > +-------------------------- > + > Offsets of the vmap_area's members. They indicate the vmalloc layer > -information. Makedumpfile can get the start address of vmalloc region. > +information. Makedumpfile gets the start address of the vmalloc region. > > (zone.free_area, MAX_ORDER) > -=========================== > +--------------------------- > + > It indicates the maximum number of the array free_area. This macro is > -used to the zone buddy allocator. User-space tools use this value to > +used by the zone buddy allocator. User-space tools use this value to > iterate the free_area. > > log_buf > -======= > -In general, console output is written to the ring buffer 'log_buf' at > -index 'log_first_idx'. It can get kernel log from the log_buf. > +------- > + > +Console output is written to the ring buffer log_buf at index > +log_first_idx. Used to get the kernel log. > > log_buf_len > -=========== > -Length of a 'log_buf'. Makedumpfile can read the number of strings > -from the log_buf. > +----------- > > -log_first_idx > -============= > -Index of the first record stored in the buffer 'log_buf'. This value > -tells the user-space tools the place where to read the strings in the > +Length of a log_buf. Used to read the number of strings from the > log_buf. > > +log_first_idx > +------------- > + > +Index of the first record stored in the buffer log_buf. Used by > +user-space tools to read the strings in the log_buf. > + > clear_idx > -========= > -The index that the next printk record to read after the last 'clear' > +--------- > + > +The index that the next printk() record to read after the last clear > command. It indicates the first record after the last SYSLOG_ACTION > _CLEAR, like issued by 'dmesg -c'. > > log_next_idx > -============ > -The index of the next record to store in the buffer 'log_buf'. It helps > -to compute the index of current strings position. > +------------ > + > +The index of the next record to store in the buffer log_buf. Used to > +compute the index of the current string position. > > printk_log > -========== > -The size of a structure 'printk_log'. It helps to compute the size of > +---------- > + > +The size of a structure printk_log. Used to compute the size of > messages, and extract dmesg log. > > (printk_log, ts_nsec|len|text_len|dict_len) > -=========================================== > -It represents these field offsets in the structure 'printk_log'. User > -space tools can parse it and detect any changes to structure down the > -line. > +------------------------------------------- > + > +It represents field offsets in struct printk_log. User space tools can > +parse it and detect any changes to structure down the line. > > (free_area.free_list, MIGRATE_TYPES) > -==================================== > +------------------------------------ > + > The number of migrate types for pages. The free_list is divided into > the array, it needs to know the number of the array. > > NR_FREE_PAGES > -============= > +------------- > + > On linux-2.6.21 or later, the number of free_pages is in > -vm_stat[NR_FREE_PAGES]. It can get the number of free pages from the > -array. > +vm_stat[NR_FREE_PAGES]. Used to get the number of free pages. > > PG_lru|PG_private|PG_swapcache|PG_swapbacked|PG_slab| > PG_hwpoision|PG_head_mask > -===================================================== > -It means the attribute of a page. These flags will be used to filter > -the free pages. > +-----------------------------------------------------a > + > +Page attributes. These flags are used to filter free pages. > > PAGE_BUDDY_MAPCOUNT_VALUE or ~PG_buddy > -====================================== > -The 'PG_buddy' flag indicates that the page is free and in the buddy > +-------------------------------------- > + > +The PG_buddy flag indicates that the page is free and in the buddy > system. Makedumpfile can exclude the free pages managed by a buddy. > > HUGETLB_PAGE_DTOR > -================= > -The 'HUGETLB_PAGE_DTOR' flag indicates the hugetlbfs pages. Makedumpfile > -will exclude these pages. > +----------------- > > -================ > -x86_64 variables > -================ > +The HUGETLB_PAGE_DTOR flag denotes hugetlbfs pages. Makedumpfile > +excludes these pages. > + > +====== > +x86_64 > +====== > > phys_base > -========= > -In x86_64, the 'phys_base' is necessary to convert virtual address of > -exported kernel symbol to physical address. > +--------- > + > +Used to convert the virtual address of an exported kernel symbol to its > +physical address. > > init_top_pgt > -============ > -The 'init_top_pgt' used to walk through the whole page table and convert > -virtual address to physical address. > +------------ > + > +Used to walk through the whole page table and convert virtual addresses > +to physical addresses. > > pgtable_l5_enabled > -================== > +------------------ > + > User-space tools need to know whether the crash kernel was in 5-level > -paging mode or not. > +paging mode. > > node_data > -========= > -This is a struct 'pglist_data' array, it stores all numa nodes information. > -In general, Makedumpfile can get the pglist_data structure from symbol > -'node_data'. > +--------- > + > +This is a struct pglist_data array and stores all numa nodes > +information. Makedumpfile gets the pglist_data structure from it. > > (node_data, MAX_NUMNODES) > -========================= > -The number of this 'node_data' array. It means the maximum number of the > -nodes in system. > +------------------------- > + > +The maximum number of the nodes in system. > > KERNELOFFSET > -============ > -Randomize the address of the kernel image. This is the offset of KASLR in > -VMCOREINFO ELF notes. It is used to compute the page offset in x86_64. If > -KASLE is disabled, this value is zero. > +------------ > + > +The kernel randomization offset. Used to compute the page offset. If > +KASLR is disabled, this value is zero. > > KERNEL_IMAGE_SIZE > -================= > -The size of 'KERNEL_IMAGE_SIZE', currently unused. > +----------------- > > -The old MODULES_VADDR need be decided by KERNEL_IMAGE_SIZE when kaslr > -enabled. Now MODULES_VADDR is not needed any more since Pratyush makes > -all VA to PA converting done by page table lookup. > +Currently unused. > > PAGE_OFFLINE_MAPCOUNT_VALUE(~PG_offline) > -======================================== > -The value of 'PG_offline' flag can be used for marking pages as logically > -offline. Makedumpfile can directly skip pages that are logically offline. > +---------------------------------------- > + > +The value of PG_offline flag can be used for marking pages as logically > +offline. Makedumpfile skips pages that are logically offline. > > sme_mask > -======== > -For AMD machine with SME feature, it indicates the secure memory encryption > -mask. Makedumpfile tools need to know whether the crash kernel was encrypted > -or not. If SME is enabled in the first kernel, the crash kernel's page > -table(pgd/pud/pmd/pte) contains the memory encryption mask, so need to > -remove the sme mask to obtain the true physical address. > +-------- > > -============= > -x86 variables > -============= > +For AMD machine with SME feature, it indicates the secure memory > +encryption mask. Makedumpfile tools need to know whether the crash > +kernel was encrypted. If SME is enabled in the first kernel, the crash > +kernel's page table (pgd/pud/pmd/pte) contains the memory encryption > +mask and this is used to remove the SME mask to obtain the true physical > +address. > + > +====== > +x86_32 > +====== > > X86_PAE > -======= > -It means the physical address extension. It has the cost of more > -page table lookup overhead, and also consumes more page table space > -per process. This flag will be used to check whether the PAE was > -enabled in crash kernel or not when converting virtual address to > -physical address. > +------- > > -============== > -ia64 variables > -============== > +Denotes whether physical address extensions are enabled. It has the cost > +of more page table lookup overhead, and also consumes more page table > +space per process. Used to check whether PAE was enabled in the crash > +kernel when converting virtual addresses to physical addresses. > + > +==== > +ia64 > +==== > > pgdat_list|(pgdat_list, MAX_NUMNODES) > -===================================== > -This is a struct 'pg_data_t' array, it stores all numa nodes information. > -And the 'MAX_NUMNODES' indicates the number of the nodes. > +------------------------------------- > + > +pg_data_t array storing all numa nodes information. MAX_NUMNODES > +indicates the number of the nodes. > > node_memblk|(node_memblk, NR_NODE_MEMBLKS) > -========================================== > +------------------------------------------ > + > List of node memory chunks. Filled when parsing SRAT table to obtain > -information about memory nodes. The 'NR_NODE_MEMBLKS' indicates the number > +information about memory nodes. NR_NODE_MEMBLKS indicates the number > of node memory chunks. > > -These values are used to compute the number of nodes in crash kernel. > +These values are used to compute the number of nodes in the crash kernel. > > node_memblk_s|(node_memblk_s, start_paddr)|(node_memblk_s, size) > -================================================================ > -The size of a struct 'node_memblk_s', and the offsets of the > -node_memblk_s's members. It helps to compute the number of nodes. > +---------------------------------------------------------------- > + > +The size of a struct node_memblk_s and the offsets of the > +node_memblk_s's members. Used to compute the number of nodes. > > PGTABLE_3|PGTABLE_4 > -=================== > +------------------- > + > User-space tools need to know whether the crash kernel was in 3-level or > -4-level paging mode. This flag can help to distinguish the page table. > +4-level paging mode. Used to distinguish the page table. > > -=============== > -arm64 variables > -=============== > +===== > +ARM64 > +===== > > VA_BITS > -======= > -The maximum number of bits for virtual addresses. This value helps to > -compute the virtual memory ranges. > +------- > + > +The maximum number of bits for virtual addresses. Used to compute the > +virtual memory ranges. > > kimage_voffset > -============== > -The offset between the kernel virtual and physical mappings. This value > -helps to translate virtual address to physical address. > +-------------- > + > +The offset between the kernel virtual and physical mappings. Used to > +translate virtual to physical addresses. > > PHYS_OFFSET > -=========== > -It indicates the physical address of the start of memory. It is similar > -with the kimage_voffset, which is used to translate virtual address to > -physical address. > +----------- > + > +Indicates the physical address of the start of memory. Similar to > +kimage_voffset, which is used to translate virtual address to physical > +address. > > KERNELOFFSET > -============ > -It is similar to x86_64. > +------------ > + > +The kernel randomization offset. Used to compute the page offset. If > +KASLR is disabled, this value is zero. > > ============= > arm variables > ============= > > ARM_LPAE > -======== > -It indicates whether the crash kernel support the large physical address > -extension. This value will tell you how to translate virtual address to > -physical address. > +-------- > > -============== > -s390 variables > -============== > +It indicates whether the crash kernel supports large physical address > +extensions. Used to translate virtual address to physical address. > + > +==== > +s390 > +==== > > lowcore_ptr > -========== > -An array with a pointer to the lowcore of every CPU. This value > -helps to print the psw and all registers information. > +---------- > + > +An array with a pointer to the lowcore of every CPU. Used to print the > +psw and all registers information. > > high_memory > -=========== > -It can get the vmalloc_start address from the high_memory symbol. > +----------- > + > +Used to get the vmalloc_start address from the high_memory symbol. > > (lowcore_ptr, NR_CPUS) > -====================== > -The maximum number of cpus. > +---------------------- > > -TODO. > +The maximum number of CPUs. > + > +======= > +powerpc > +======= > > -powerpc variables > -================= > > node_data|(node_data, MAX_NUMNODES) > -=================================== > -Please refer to common variables. > +----------------------------------- > + > +See above. > > contig_page_data > -================ > -Please refer to common variables. > +---------------- > + > +See above. > > vmemmap_list > -============ > -The 'vmemmap_list' maintains the entire vmemmap physical mapping. It > -can get vmemmap list count and populate vmemmap regions info. If the > -vmemmap address translation information is stored in crash kernel, > -which helps to translate vmemmap kernel virtual addresses. > +------------ > + > +The vmemmap_list maintains the entire vmemmap physical mapping. It can > +get vmemmap list count and populate vmemmap regions info. If the vmemmap > +address translation information is stored in the crash kernel, it helps > +to translate vmemmap kernel virtual addresses. > > mmu_vmemmap_psize > -================= > -The size of a page. It will try to use this page sizes for vmemmap if > -support. This value helps to translate virtual address to physical > -address. > +----------------- > + > +The size of a page. Used to translate address to physical addresses. > > mmu_psize_defs > -============== > -It stores a variety of pages, such as the page size is 4k, 64k, or 16M. > +-------------- > > -It depends on this value when making vtop translations. > +Page size definitions, i.e. 4k, 64k, or 16M. > + > +Used to make vtop translations. > > vmemmap_backing|(vmemmap_backing, list)|(vmemmap_backing, phys)| > (vmemmap_backing, virt_addr) > -================================================================ > +---------------------------------------------------------------- > + > The vmemmap virtual address space management does not have a traditional > page table to track which virtual struct pages are backed by physical > mapping. The virtual to physical mappings are tracked in a simple linked > list format. > > -And user-space tools need to know the offset of 'list', 'phys' and > -'virt_addr'. It depends on these values when computing the count of > -vmemmap regions. > +User-space tools need to know the offset of list, phys and virt_addr > +when computing the count of vmemmap regions. > > mmu_psize_def|(mmu_psize_def, shift) > -==================================== > -The size of a struct 'mmu_psize_def', and the offset of mmu_psize_def's > +------------------------------------ > + > +The size of a struct mmu_psize_def and the offset of mmu_psize_def's > member. > > -These values help to make the vtop translations. > +Used in vtop translations. > > -============ > -sh variables > -============ > +== > +sh > +== > > node_data|(node_data, MAX_NUMNODES) > -=================================== > -It is similar to X86_64, please refer to above description. > +----------------------------------- > + > +See above. > > X2TLB > -===== > -It indicates whether the crash kernel enables the extended mode of the SH. > +----- > > -TODO. > +Indicates whether the crash kernel enables SH extended mode. > _______________________________________________ kexec mailing list kexec@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/kexec
