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author | H.J. Lu <hjl.tools@gmail.com> | 2024-02-29 11:17:01 -0800 |
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committer | H.J. Lu <hjl.tools@gmail.com> | 2024-04-03 09:11:00 -0700 |
commit | 9ba56acee518492cfe21434b974c807f52ac7950 (patch) | |
tree | 33eba694516786c5249f41fae1c4b60abd068723 /bfd/cache.c | |
parent | f89ae595dd1f5195dd6e8e57bc2217463c436888 (diff) | |
download | binutils-9ba56acee518492cfe21434b974c807f52ac7950.zip binutils-9ba56acee518492cfe21434b974c807f52ac7950.tar.gz binutils-9ba56acee518492cfe21434b974c807f52ac7950.tar.bz2 |
elf: Use mmap to map in read-only sections
There are many linker input files in LLVM debug build with huge string
sections. All these string sections can be treated as read-only. But
linker copies all of them into memory which consumes huge amount of
memory and slows down linker significantly.
Add _bfd_mmap_readonly_persistent and _bfd_mmap_readonly_temporary to
mmap in reado-only sections with size >= 4 * page size.
NB: All string sections in valid ELF inputs must be null terminated.
There is no need to terminate it again and string sections are mmapped
as read-only.
* bfd.c (bfd_mmapped_entry): New.
(bfd_mmapped): Likewise.
(bfd): Add mmapped.
* bfdwin.c (bfd_get_file_window): Use _bfd_pagesize.
* cache.c (cache_bmmap): Remove pagesize_m1 and use pagesize_m1
instead.
* elf.c (bfd_elf_get_str_section): Call
_bfd_mmap_readonly_persistent instead of _bfd_alloc_and_read.
Don't terminate the string section again.
(get_hash_table_data): Call _bfd_mmap_readonly_temporary and
_bfd_munmap_readonly_temporary instead of _bfd_malloc_and_read
and free.
(_bfd_elf_get_dynamic_symbols): Call _bfd_mmap_readonly_persistent
instead of _bfd_alloc_and_read. Don't terminate the string
section again. Call _bfd_mmap_readonly_temporary and
_bfd_munmap_readonly_temporary instead of _bfd_malloc_and_read
and free.
(_bfd_elf_slurp_version_tables): Call _bfd_mmap_readonly_temporary
and _bfd_munmap_readonly_temporary instead of _bfd_malloc_and_read
and free.
* elflink.c (bfd_elf_link_record_dynamic_symbol): Use bfd_malloc
to get the unversioned symbol.
* libbfd-in.h (_bfd_pagesize): New.
(_bfd_pagesize_m1): Likewise.
(_bfd_minimum_mmap_size): Likewise.
(_bfd_mmap_readonly_persistent): Likewise.
(_bfd_mmap_readonly_temporary): Likewise.
(_bfd_munmap_readonly_temporary): Likewise.
* libbfd.c
(bfd_allocate_mmapped_page): New.
(_bfd_mmap_readonly_temporary): Likewise.
(_bfd_munmap_readonly_temporary): Likewise.
(_bfd_mmap_readonly_persistent): Likewise.
(_bfd_pagesize): Likewise.
(_bfd_pagesize_m1): Likewise.
(_bfd_minimum_mmap_size): Likewise.
(bfd_init_pagesize): Likewise.
* lynx-core.c (lynx_core_file_p): Use _bfd_pagesize.
* opncls.c (_bfd_delete_bfd): Munmap tracked mmapped memories.
* sysdep.h (MAP_ANONYMOUS): New. Define if undefined.
* bfd-in2.h: Regenerated.
* libbfd.h: Likewise.
Diffstat (limited to 'bfd/cache.c')
-rw-r--r-- | bfd/cache.c | 7 |
1 files changed, 2 insertions, 5 deletions
diff --git a/bfd/cache.c b/bfd/cache.c index d0e7be2..0f994c7 100644 --- a/bfd/cache.c +++ b/bfd/cache.c @@ -494,10 +494,10 @@ cache_bmmap (struct bfd *abfd ATTRIBUTE_UNUSED, #ifdef HAVE_MMAP else { - static uintptr_t pagesize_m1; + uintptr_t pagesize_m1 = _bfd_pagesize_m1; FILE *f; file_ptr pg_offset; - bfd_size_type pg_len; + size_t pg_len; f = bfd_cache_lookup (abfd, CACHE_NO_SEEK_ERROR); if (f == NULL) @@ -506,9 +506,6 @@ cache_bmmap (struct bfd *abfd ATTRIBUTE_UNUSED, return ret; } - if (pagesize_m1 == 0) - pagesize_m1 = getpagesize () - 1; - /* Align. */ pg_offset = offset & ~pagesize_m1; pg_len = (len + (offset - pg_offset) + pagesize_m1) & ~pagesize_m1; |