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| author | Alan Modra <amodra@gmail.com> | 2023-08-07 08:28:55 +0930 |
|---|---|---|
| committer | Alan Modra <amodra@gmail.com> | 2023-08-09 08:47:35 +0930 |
| commit | f82ee0c8dc4ee32556e23e6cd83ef083618f704f (patch) | |
| tree | 6775612169afe1cd7270f7fe4c10f5b451dfdb44 /bfd/bfdio.c | |
| parent | 7570a17cbbe647db6260ae2391f92c0509de7924 (diff) | |
| download | gdb-f82ee0c8dc4ee32556e23e6cd83ef083618f704f.zip gdb-f82ee0c8dc4ee32556e23e6cd83ef083618f704f.tar.gz gdb-f82ee0c8dc4ee32556e23e6cd83ef083618f704f.tar.bz2 | |
PR30724, cygwin ld performance regression since 014a602b86
According to the reporter of this bug the newlib fseek implementation
is likely slowed down by locking and fflush, only attempting to
optimise seeks when the file is opened read-only. Thus when writing
the output we get a dramatic slowdown due to commit 014a602b86.
PR 30724
* bfd.c (enum bfd_last_io): New.
(struct bfd): Add last_io field.
* bfd-in2.h: Regenerate.
* bfd-io.c (bfd_bread, bfd_bwrite): Force seek if last_io is
opposite direction.
(bfd_seek): Reinstate optimisation for seek to same position.
Diffstat (limited to 'bfd/bfdio.c')
| -rw-r--r-- | bfd/bfdio.c | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/bfd/bfdio.c b/bfd/bfdio.c index 22c39a7..e0d47b3 100644 --- a/bfd/bfdio.c +++ b/bfd/bfdio.c @@ -279,6 +279,14 @@ bfd_bread (void *ptr, bfd_size_type size, bfd *abfd) return -1; } + if (abfd->last_io == bfd_io_write) + { + abfd->last_io = bfd_io_force; + if (bfd_seek (abfd, 0, SEEK_CUR) != 0) + return -1; + } + abfd->last_io = bfd_io_read; + nread = abfd->iovec->bread (abfd, ptr, size); if (nread != -1) abfd->where += nread; @@ -313,6 +321,14 @@ bfd_bwrite (const void *ptr, bfd_size_type size, bfd *abfd) return -1; } + if (abfd->last_io == bfd_io_read) + { + abfd->last_io = bfd_io_force; + if (bfd_seek (abfd, 0, SEEK_CUR) != 0) + return -1; + } + abfd->last_io = bfd_io_write; + nwrote = abfd->iovec->bwrite (abfd, ptr, size); if (nwrote != -1) abfd->where += nwrote; @@ -456,6 +472,13 @@ bfd_seek (bfd *abfd, file_ptr position, int direction) if (direction != SEEK_CUR) position += offset; + if (((direction == SEEK_CUR && position == 0) + || (direction == SEEK_SET && (ufile_ptr) position == abfd->where)) + && abfd->last_io != bfd_io_force) + return 0; + + abfd->last_io = bfd_io_seek; + result = abfd->iovec->bseek (abfd, position, direction); if (result != 0) { |