From: Qiao Nuohan <[email protected]> mappage_elf_parallel is used to enable mmaping elf format to memory parallelly. later patch will will use the mmapped memory to get data of each page. fd_memory and mmap_cache should be initialized and offered to each threads individually to avoid conflict.
Signed-off-by: Qiao Nuohan <[email protected]> --- makedumpfile.c | 97 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ makedumpfile.h | 14 ++++++++ 2 files changed, 111 insertions(+), 0 deletions(-) diff --git a/makedumpfile.c b/makedumpfile.c index 10b6738..0f71ce7 100644 --- a/makedumpfile.c +++ b/makedumpfile.c @@ -395,6 +395,46 @@ update_mmap_range(off_t offset, int initial) { } static int +update_mmap_range_parallel(int fd_memory, off_t offset, + struct mmap_cache *mmap_cache) +{ + off_t start_offset, end_offset; + off_t map_size; + off_t max_offset = get_max_file_offset(); + off_t pt_load_end = offset_to_pt_load_end(offset); + + /* + * mmap_buf must be cleaned + */ + if (mmap_cache->mmap_buf != MAP_FAILED) + munmap(mmap_cache->mmap_buf, mmap_cache->mmap_end_offset + - mmap_cache->mmap_start_offset); + + /* + * offset for mmap() must be page aligned. + */ + start_offset = roundup(offset, info->page_size); + end_offset = MIN(max_offset, round(pt_load_end, info->page_size)); + + if (!pt_load_end || (end_offset - start_offset) <= 0) + return FALSE; + + map_size = MIN(end_offset - start_offset, info->mmap_region_size); + + mmap_cache->mmap_buf = mmap(NULL, map_size, PROT_READ, MAP_PRIVATE, + fd_memory, start_offset); + + if (mmap_cache->mmap_buf == MAP_FAILED) { + return FALSE; + } + + mmap_cache->mmap_start_offset = start_offset; + mmap_cache->mmap_end_offset = start_offset + map_size; + + return TRUE; +} + +static int is_mapped_with_mmap(off_t offset) { if (info->flag_usemmap == MMAP_ENABLE @@ -405,6 +445,15 @@ is_mapped_with_mmap(off_t offset) { return FALSE; } +static int +is_mapped_with_mmap_parallel(off_t offset, struct mmap_cache *mmap_cache) { + if (offset >= mmap_cache->mmap_start_offset + && offset < mmap_cache->mmap_end_offset) + return TRUE; + else + return FALSE; +} + int initialize_mmap(void) { unsigned long long phys_start; @@ -459,6 +508,54 @@ mappage_elf(unsigned long long paddr) return info->mmap_buf + (offset - info->mmap_start_offset); } +static char * +mappage_elf_parallel(int fd_memory, unsigned long long paddr, + struct mmap_cache *mmap_cache) +{ + off_t offset, offset2; + int flag_usemmap; + + pthread_rwlock_rdlock(&info->usemmap_rwlock); + flag_usemmap = info->flag_usemmap; + pthread_rwlock_unlock(&info->usemmap_rwlock); + if (flag_usemmap != MMAP_ENABLE) + return NULL; + + offset = paddr_to_offset(paddr); + if (!offset || page_is_fractional(offset)) + return NULL; + + offset2 = paddr_to_offset(paddr + info->page_size - 1); + if (!offset2) + return NULL; + + if (offset2 - offset != info->page_size - 1) + return NULL; + + if (!is_mapped_with_mmap_parallel(offset, mmap_cache) && + !update_mmap_range_parallel(fd_memory, offset, mmap_cache)) { + ERRMSG("Can't read the dump memory(%s) with mmap().\n", + info->name_memory); + + ERRMSG("This kernel might have some problems about mmap().\n"); + ERRMSG("read() will be used instead of mmap() from now.\n"); + + /* + * Fall back to read(). + */ + pthread_rwlock_wrlock(&info->usemmap_rwlock); + info->flag_usemmap = MMAP_DISABLE; + pthread_rwlock_unlock(&info->usemmap_rwlock); + return NULL; + } + + if (offset < mmap_cache->mmap_start_offset || + offset + info->page_size > mmap_cache->mmap_end_offset) + return NULL; + + return mmap_cache->mmap_buf + (offset - mmap_cache->mmap_start_offset); +} + static int read_from_vmcore(off_t offset, void *bufptr, unsigned long size) { diff --git a/makedumpfile.h b/makedumpfile.h index d2fadbd..939850f 100644 --- a/makedumpfile.h +++ b/makedumpfile.h @@ -42,6 +42,7 @@ #include "dwarf_info.h" #include "diskdump_mod.h" #include "sadump_mod.h" +#include <pthread.h> /* * Result of command @@ -913,6 +914,15 @@ typedef unsigned long int ulong; typedef unsigned long long int ulonglong; /* + * for parallel process + */ +struct mmap_cache { + char *mmap_buf; + off_t mmap_start_offset; + off_t mmap_end_offset; +}; + +/* * makedumpfile header * For re-arranging the dump data on different architecture, all the * variables are defined by 64bits. The size of signature is aligned @@ -1177,6 +1187,10 @@ struct DumpInfo { * for cyclic_splitting mode, setup splitblock_size */ long long splitblock_size; + /* + * for parallel process + */ + pthread_rwlock_t usemmap_rwlock; }; extern struct DumpInfo *info; -- 1.7.1 _______________________________________________ kexec mailing list [email protected] http://lists.infradead.org/mailman/listinfo/kexec
