Re: [PATCH v3] app/test: fix stack overflow in lpm6_perf_autotest

[Andre Muezerie <andremue@linux.microsoft.com>]

On Wed, Mar 05, 2025 at 10:08:33AM +0000, Bruce Richardson wrote:
> On Wed, Dec 18, 2024 at 07:21:26AM -0800, Andre Muezerie wrote:
> > Test lpm6_perf_autotest was hitting a stack overflow on Windows
> > with both MSVC and Clang.
> > 
> > The fix is to move some of the data from the stack to the heap.
> > 
> > Signed-off-by: Andre Muezerie <andremue@linux.microsoft.com>
> > ---
> >  app/test/test_lpm6_perf.c | 13 +++++++++++--
> >  1 file changed, 11 insertions(+), 2 deletions(-)
> > 
> > diff --git a/app/test/test_lpm6_perf.c b/app/test/test_lpm6_perf.c
> > index 1860a99ed6..59df0a958a 100644
> > --- a/app/test/test_lpm6_perf.c
> > +++ b/app/test/test_lpm6_perf.c
> > @@ -10,6 +10,7 @@
> >  
> >  #include <rte_cycles.h>
> >  #include <rte_random.h>
> > +#include <rte_malloc.h>
> >  #include <rte_memory.h>
> >  #include <rte_lpm6.h>
> >  
> > @@ -117,8 +118,13 @@ test_lpm6_perf(void)
> >  	total_time = 0;
> >  	count = 0;
> >  
> > -	struct rte_ipv6_addr ip_batch[NUM_IPS_ENTRIES];
> > -	int32_t next_hops[NUM_IPS_ENTRIES];
> > +	struct rte_ipv6_addr *ip_batch = rte_calloc("ip_batch",
> > +			NUM_IPS_ENTRIES, sizeof(struct rte_ipv6_addr), 0);
> > +	TEST_LPM_ASSERT(ip_batch != NULL);
> > +
> > +	int32_t *next_hops = rte_calloc("next_hops",
> > +			NUM_IPS_ENTRIES, sizeof(int32_t), 0);
> > +	TEST_LPM_ASSERT(next_hops != NULL);
> >  
> 
> While I don't think we need to use the "rte_" versions of allocation, this
> is still an ok fix - and I see that in v1 regular malloc was used.

The reviewers had different opinions on which allocator function
should be used, that's why it was changed. Thanks for being flexible on this.

> 
> With either calloc or rte_calloc used.
> 
> Acked-by: Bruce Richardson <bruce.richardson@intel.com>
> 
> 
> >  	for (i = 0; i < NUM_IPS_ENTRIES; i++)
> >  		ip_batch[i] = large_ips_table[i].ip;
> > @@ -153,6 +159,9 @@ test_lpm6_perf(void)
> >  	printf("Average LPM Delete: %g cycles\n",
> >  			(double)total_time / NUM_ROUTE_ENTRIES);
> >  
> > +	rte_free(next_hops);
> > +	rte_free(ip_batch);
> > +
> >  	rte_lpm6_delete_all(lpm);
> >  	rte_lpm6_free(lpm);
> >  
> > -- 
> > 2.47.0.vfs.0.3
> >