similar to: [PATCH v2 0/2] daemon: Move the useful 'is_zero' function into common code.

This is largely a simple refactoring, but it combines another definition of this function from virt-builder which had a slightly different prototype. --- builder/pxzcat-c.c | 20 +------------------- daemon/daemon.h | 18 ------------------ lib/guestfs-internal-all.h | 18 ++++++++++++++++++ 3 files changed, 19 insertions(+), 37 deletions(-) diff --git a/builder/pxzcat-c.c

On Wed, Apr 19, 2017 at 09:35:16AM -0500, Eric Blake wrote: > On 04/19/2017 09:17 AM, Richard W.M. Jones wrote: > > This is largely a simple refactoring, but it combines another > > definition of this function from virt-builder which had a slightly > > different prototype. > > --- > > > +/* Return true iff the buffer is all zero bytes. > > + * > > +

On 04/19/2017 09:17 AM, Richard W.M. Jones wrote: > This is largely a simple refactoring, but it combines another > definition of this function from virt-builder which had a slightly > different prototype. > --- > +/* Return true iff the buffer is all zero bytes. > + * > + * Note that gcc is smart enough to optimize this properly: > + *

Various changes/fixes to use smaller stack frames. Rich.

On Wednesday, 19 April 2017 18:46:37 CEST Richard W.M. Jones wrote: > v1 -> v2: > > The first patch is the same (the pure refactoring), but in the second > patch I implement Eric Blake's suggested version. LGTM -- can you please add Eric's text to the comment of is_zero, so it is easier to remember why the 16-bytes trick is done? Thanks, -- Pino Toscano

Fix and/or document issues raised in this thread: https://www.redhat.com/archives/libguestfs/2017-February/msg00010.html Rich.

On 1/30/20 8:05 AM, Richard W.M. Jones wrote: > Fast testing whether the AIO buffer (or regions within it) contain all > zeroes, which allows Python code to quickly do sparsification when > copying. > > This includes the iszero.h header from nbdkit which is distributed > under a compatible license. > --- > common/include/Makefile.am | 5 +-- >

--- src/inspect-apps.c | 13 ++++++++++++- src/inspect-fs-windows.c | 6 ++++++ src/journal.c | 5 +++++ 3 files changed, 23 insertions(+), 1 deletion(-) diff --git a/src/inspect-apps.c b/src/inspect-apps.c index 20cf00a..8fbae9c 100644 --- a/src/inspect-apps.c +++ b/src/inspect-apps.c @@ -35,11 +35,22 @@ #include <sys/endian.h> #endif -/* be32toh is usually a macro

More posix_fadvise stuff, and document what Linux really does with these calls. Also fixes a nasty bug in virt-builder. Rich.

On Thu, Jan 30, 2020 at 02:29:21PM +0000, Richard W.M. Jones wrote: >On Thu, Jan 30, 2020 at 08:16:30AM -0600, Eric Blake wrote: >> On 1/30/20 8:05 AM, Richard W.M. Jones wrote: >> >Fast testing whether the AIO buffer (or regions within it) contain all >> >zeroes, which allows Python code to quickly do sparsification when >> >copying. >> > >>

--- pxzcat.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/pxzcat.c b/pxzcat.c index 4ab8689..9bcdc36 100644 --- a/pxzcat.c +++ b/pxzcat.c @@ -29,10 +29,11 @@ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ +#define _GNU_SOURCE #include <config.h>

The way we used posix_fadvise was wrong, and yet right! Rich.

Fast testing whether the AIO buffer (or regions within it) contain all zeroes, which allows Python code to quickly do sparsification when copying. This includes the iszero.h header from nbdkit which is distributed under a compatible license. --- common/include/Makefile.am | 5 +-- common/include/iszero.h | 63 +++++++++++++++++++++++++++++++++++++ generator/generator | 17

On Thu, Jan 30, 2020 at 04:16:09PM +0100, Martin Kletzander wrote: > I know this probably got answered somewhere, but I've never gotten > any when asking myself. So let me use this opportunity. > > Because I really despise useless processes and duplicated > information I always hated the way all the "mandatory" file headers. > As far as I understand it's

When sparse_array_zero() is used for a range larger than a page, there's no need to waste time in memset() or is_zero() - we already know the page will be free()d. Signed-off-by: Eric Blake <eblake@redhat.com> --- Here's a fun one :) common/sparse/sparse.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/common/sparse/sparse.c b/common/sparse/sparse.c

--- pxzcat.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/pxzcat.c b/pxzcat.c index 9bcdc36..55ccfc0 100644 --- a/pxzcat.c +++ b/pxzcat.c @@ -44,10 +44,11 @@ #include <sys/types.h> #include <error.h> #include <errno.h> #include <getopt.h> #include <pthread.h> +#include <linux/falloc.h> #include <lzma.h> #define DEBUG

Just like with index-parse.h, also index-struct.h is a dependency of index-parser-c.c which automake cannot generate correctly. Thus, add it manually. --- builder/Makefile.am | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/builder/Makefile.am b/builder/Makefile.am index fc4c552..6565abb 100644 --- a/builder/Makefile.am +++ b/builder/Makefile.am @@ -231,7 +231,7 @@ CLEANFILES

On Thu, Jan 30, 2020 at 08:16:30AM -0600, Eric Blake wrote: > On 1/30/20 8:05 AM, Richard W.M. Jones wrote: > >Fast testing whether the AIO buffer (or regions within it) contain all > >zeroes, which allows Python code to quickly do sparsification when > >copying. > > > >This includes the iszero.h header from nbdkit which is distributed > >under a compatible

GCC has two warnings related to large stack frames. We were already using the -Wframe-larger-than warning, but this reduces the threshold from 10000 to 5000 bytes. However that warning only covers the static part of frames (not alloca). So this change also enables -Wstack-usage=10000 which covers both the static and dynamic usage (alloca and variable length arrays). Multiple changes are made

See individual patches for details. Pino Toscano (5): Include signal.h Remove unused variables Push -Wsuggest-attribute=noreturn only with GCC tests: do not set libguestfs environment variables Define the GCC version macro Makefile.am | 2 +- conversion.c | 3 +++ p2v.h | 7 +++++++ ssh.c | 8 +++++--- 4 files changed, 16 insertions(+), 4 deletions(-) -- 2.21.0