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authorGravatar Denys Vlasenko <vda.linux@googlemail.com>2014-12-07 00:44:00 +0100
committerGravatar Denys Vlasenko <vda.linux@googlemail.com>2014-12-07 00:44:00 +0100
commitb4c11c139717729b8257ee9382d4e5ed713d4dde (patch)
tree0b6c5edd491090c54b09657ef63c711a118a4e9d /archival/tar.c
parente7800f351ad9eca012fe27a1c9234692a04419e7 (diff)
downloadbusybox-b4c11c139717729b8257ee9382d4e5ed713d4dde.tar.gz
busybox-b4c11c139717729b8257ee9382d4e5ed713d4dde.tar.bz2
libarchive: add capability to unpack to mem.buffer
The performance and number of processes for a "depmod -a" with gzipped modules was abysmal. This patch adds a code path without fork, benefiting all users of xmalloc_open_zipped_read_close. "modinfo radeon.ko.gz", a single-file reader, got 30% faster. "depmod -a", which used to fork over 800 times, got 20% faster. Heavily based on a patch by Lauri Kasanen <curaga@operamail.com> function old new delta setup_transformer_on_fd - 159 +159 transformer_write - 122 +122 fork_transformer - 112 +112 xmalloc_open_zipped_read_close 63 118 +55 read_bunzip 1866 1896 +30 xtransformer_write - 19 +19 unzip_main 2449 2462 +13 bbunpack 755 766 +11 unpack_lzma_stream 2717 2723 +6 unpack_xz_stream 2393 2397 +4 unpack_Z_stream 1173 1175 +2 inflate_unzip 111 105 -6 check_signature16 70 63 -7 unpack_bz2_stream 359 349 -10 unpack_unxz 12 - -12 unpack_unlzma 12 - -12 unpack_uncompress 12 - -12 unpack_gunzip 12 - -12 unpack_bunzip2 12 - -12 open_transformer 106 92 -14 inflate_unzip_internal 1945 1916 -29 unpack_gz_stream 693 655 -38 open_zipped 89 47 -42 setup_unzip_on_fd 142 53 -89 ------------------------------------------------------------------------------ (add/remove: 4/5 grow/shrink: 7/8 up/down: 533/-295) Total: 238 bytes Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Diffstat (limited to 'archival/tar.c')
-rw-r--r--archival/tar.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/archival/tar.c b/archival/tar.c
index 7897a4af6..5bd473aac 100644
--- a/archival/tar.c
+++ b/archival/tar.c
@@ -1171,7 +1171,7 @@ int tar_main(int argc UNUSED_PARAM, char **argv)
}
if (opt & OPT_ANY_COMPRESS) {
- USE_FOR_MMU(IF_DESKTOP(long long) int FAST_FUNC (*xformer)(transformer_state_t *xstate, int src_fd, int dst_fd);)
+ USE_FOR_MMU(IF_DESKTOP(long long) int FAST_FUNC (*xformer)(transformer_state_t *xstate);)
USE_FOR_NOMMU(const char *xformer_prog;)
if (opt & OPT_COMPRESS)
@@ -1190,7 +1190,7 @@ int tar_main(int argc UNUSED_PARAM, char **argv)
USE_FOR_MMU(xformer = unpack_xz_stream;)
USE_FOR_NOMMU(xformer_prog = "unxz";)
- open_transformer_with_sig(tar_handle->src_fd, xformer, xformer_prog);
+ fork_transformer_with_sig(tar_handle->src_fd, xformer, xformer_prog);
/* Can't lseek over pipes */
tar_handle->seek = seek_by_read;
/*tar_handle->offset = 0; - already is */