Re: [Qemu-devel] [PATCH v4 1/6] cutils: extract buffer_is_zero() from qemu-img.c
On Tue, Jan 24, 2012 at 3:03 PM, Kevin Wolf kw...@redhat.com wrote: Am 18.01.2012 15:59, schrieb Stefan Hajnoczi: @@ -303,6 +303,40 @@ void qemu_iovec_memset_skip(QEMUIOVector *qiov, int c, size_t count, } } +/* + * Checks if a buffer is all zeroes + * + * Attention! The len must be a multiple of 4 * sizeof(long) due to + * restriction of optimizations in this function. + */ Sounds like something to assert(), while you're touching the code. Okay, will fix. Stefan
Re: [Qemu-devel] [PATCH v4 1/6] cutils: extract buffer_is_zero() from qemu-img.c
Am 18.01.2012 15:59, schrieb Stefan Hajnoczi: The qemu-img.c:is_not_zero() function checks if a buffer contains all zeroes. This function will come in handy for zero-detection in the block layer, so clean it up and move it to cutils.c. Note that the function now returns true if the buffer is all zeroes. This avoids the double-negatives (i.e. !is_not_zero()) that the old function can cause in callers. Signed-off-by: Stefan Hajnoczi stefa...@linux.vnet.ibm.com --- cutils.c | 34 ++ qemu-common.h |2 ++ qemu-img.c| 46 +++--- 3 files changed, 43 insertions(+), 39 deletions(-) diff --git a/cutils.c b/cutils.c index a6ffd46..2ea9c3c 100644 --- a/cutils.c +++ b/cutils.c @@ -303,6 +303,40 @@ void qemu_iovec_memset_skip(QEMUIOVector *qiov, int c, size_t count, } } +/* + * Checks if a buffer is all zeroes + * + * Attention! The len must be a multiple of 4 * sizeof(long) due to + * restriction of optimizations in this function. + */ Sounds like something to assert(), while you're touching the code. Kevin
