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| author | Denys Vlasenko | 2010-03-19 14:34:30 +0100 |
|---|---|---|
| committer | Denys Vlasenko | 2010-03-19 14:34:30 +0100 |
| commit | bcda0042e2313d65a835b874c78bf215d743a844 (patch) | |
| tree | 774e7772ac513cd18ba8d394db44839ea9bfe2d9 /libbb/copyfd.c | |
| parent | 892d4b6b3d7e9950ff3708ca957e1e0590dd5a2d (diff) | |
| download | busybox-bcda0042e2313d65a835b874c78bf215d743a844.zip busybox-bcda0042e2313d65a835b874c78bf215d743a844.tar.gz | |
libbb/copyfd.c: don't mmap a largish buffer if we only want to copy a few kb
function old new delta
bb_full_fd_action 283 295 +12
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Diffstat (limited to 'libbb/copyfd.c')
| -rw-r--r-- | libbb/copyfd.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/libbb/copyfd.c b/libbb/copyfd.c index c5f8b5b..f42eb76 100644 --- a/libbb/copyfd.c +++ b/libbb/copyfd.c @@ -22,6 +22,8 @@ static off_t bb_full_fd_action(int src_fd, int dst_fd, off_t size) char *buffer; int buffer_size; + if (size > 0 && size <= 4 * 1024) + goto use_small_buf; /* We want page-aligned buffer, just in case kernel is clever * and can do page-aligned io more efficiently */ buffer = mmap(NULL, CONFIG_FEATURE_COPYBUF_KB * 1024, @@ -30,6 +32,7 @@ static off_t bb_full_fd_action(int src_fd, int dst_fd, off_t size) /* ignored: */ -1, 0); buffer_size = CONFIG_FEATURE_COPYBUF_KB * 1024; if (buffer == MAP_FAILED) { + use_small_buf: buffer = alloca(4 * 1024); buffer_size = 4 * 1024; } |