Oh, wait, this is not a path! This is the stack for a graph visit, and the limit is not the maximum length of the path, but rather the number of nodes in the graph.
In other words, QOS_PATH_MAX_ELEMENT_SIZE is being overloaded and using it in qos_node_stack is wrong. The solution is to use a linked list there, for now the patch is okay. Paolo Il mer 28 set 2022, 10:48 Alex Bennée <alex.ben...@linaro.org> ha scritto: > > Paolo Bonzini <pbonz...@redhat.com> writes: > > > What is an example of one such huge path? This would mean that LTO is > changing the set of tests that are run, which is > > unexpected. > > It does look like the LTO build runs more tests although its hard to > diff as the order if different: > > ➜ grep "list" without-lto | wc -l > 201 > 🕙09:45:35 alex@zen:qemu.git/builds/arm.all on gitdm/next [$!?⇡] > ➜ grep "list" ../debug/with-lto | wc -l > 195 > > Logs attached: > > > > > > Paolo > > > > Il mar 27 set 2022, 23:35 Alex Bennée <alex.ben...@linaro.org> ha > scritto: > > > > It seems the depth of path we need to support can vary depending on > > the order of the init constructors getting called. It seems > > --enable-lto shuffles things around just enough to push you over the > > limit. > > > > Signed-off-by: Alex Bennée <alex.ben...@linaro.org> > > Fixes: https://gitlab.com/qemu-project/qemu/-/issues/1186 > > --- > > tests/qtest/libqos/qgraph.h | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/tests/qtest/libqos/qgraph.h b/tests/qtest/libqos/qgraph.h > > index 6e94824d09..5c0046e989 100644 > > --- a/tests/qtest/libqos/qgraph.h > > +++ b/tests/qtest/libqos/qgraph.h > > @@ -24,7 +24,7 @@ > > #include "libqos-malloc.h" > > > > /* maximum path length */ > > -#define QOS_PATH_MAX_ELEMENT_SIZE 50 > > +#define QOS_PATH_MAX_ELEMENT_SIZE 64 > > > > typedef struct QOSGraphObject QOSGraphObject; > > typedef struct QOSGraphNode QOSGraphNode; > > -- > > 2.34.1 > > > -- > Alex Bennée >
