From: "Ananyev, Konstantin" <konstantin.ananyev@intel.com>
To: "Van Haaren, Harry" <harry.van.haaren@intel.com>,
"dev@dpdk.org" <dev@dpdk.org>
Cc: "pbhagavatula@caviumnetworks.com"
<pbhagavatula@caviumnetworks.com>,
"Van Haaren, Harry" <harry.van.haaren@intel.com>,
"thomas@monjalon.net" <thomas@monjalon.net>
Subject: Re: [dpdk-dev] [PATCH v2] test: fix debug autotest with eal cleanup addition
Date: Wed, 31 Jan 2018 13:53:15 +0000 [thread overview]
Message-ID: <2601191342CEEE43887BDE71AB977258905663C3@IRSMSX103.ger.corp.intel.com> (raw)
In-Reply-To: <1517336769-18052-1-git-send-email-harry.van.haaren@intel.com>
Hi Harry,
> -----Original Message-----
> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Harry van Haaren
> Sent: Tuesday, January 30, 2018 6:26 PM
> To: dev@dpdk.org
> Cc: pbhagavatula@caviumnetworks.com; Van Haaren, Harry <harry.van.haaren@intel.com>; thomas@monjalon.net
> Subject: [dpdk-dev] [PATCH v2] test: fix debug autotest with eal cleanup addition
>
> Before this patch, the debug_autotest would call fork(),
> call rte_panic() or rte_exit() in the child process, and
> examine the return code to verify that rte_panic() and
> rte_exit() were correctly reporting failures.
>
> With the inclusion of the rte_eal_cleanup() patch, rte_exit()
> was modified to cleanly tear-down EAL allocations. Currently
> only one library (service cores) is allocated by EAL at startup
> and should be cleaned up. This library has a check on a normal
> (non-hugepage) variable to protect against double cleanup. The
> service cores finalize() function itself frees back hugepage mem.
>
> Given the fork() approach from the unit test, and the fact that
> the double-free check is on an ordinary variable, causes multiple
> child processed (fork()-ed from the unit-test runner) to attempt
> to free the huge-page memory multiple times. The variable to
> protect against double-cleanup was not effective, as the fork()
> would restore it to show initialized in the next child.
>
> The solution is to call rte_service_finalize() *before* calling
> fork(), which results in the service cores double-cleanup variable
> to be zero before the fork(), and hence the child processes never
> free the hugepage service-cores memory (correct behavior, as the
> unit-test suite is still running, and owns the hugepages).
Ok, you fixed it in UT, but what to do other apps that use fork()?
Let say our examples/multi_process/l2fwd_fork uses fork() to
spawn child processes instead of threads.
Might be some generic way is needed: let say at fork time setup some
global to indicate that it is a child process and it shouldn't call rte_finalize() or so.
Konstantin
>
> Fixes: aec9c13c5257 ("eal: add function to release internal resources")
>
> Reported-by: Pavan Nikhilesh <pbhagavatula@caviumnetworks.com>
> Signed-off-by: Harry van Haaren <harry.van.haaren@intel.com>
>
> ---
>
> v2:
> - Fix 2 typo/spello mistakes in commit message
>
> Cc: thomas@monjalon.net
>
> Please consider for including in RC2 as this fixes the
> currently failing debug_autotest.
>
> ---
> test/test/test_debug.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/test/test/test_debug.c b/test/test/test_debug.c
> index dd0de44..faf2cf5 100644
> --- a/test/test/test_debug.c
> +++ b/test/test/test_debug.c
> @@ -10,6 +10,7 @@
> #include <rte_debug.h>
> #include <rte_common.h>
> #include <rte_eal.h>
> +#include <rte_service_component.h>
>
> #include "test.h"
>
> @@ -50,6 +51,11 @@ test_exit_val(int exit_val)
> int pid;
> int status;
>
> + /* manually cleanup EAL memory, as the fork() below would otherwise
> + * cause the same hugepages to be free()-ed multiple times.
> + */
> + rte_service_finalize();
> +
> pid = fork();
>
> if (pid == 0)
> --
> 2.7.4
next prev parent reply other threads:[~2018-01-31 13:53 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-30 18:21 [dpdk-dev] [PATCH] " Harry van Haaren
2018-01-30 18:26 ` [dpdk-dev] [PATCH v2] " Harry van Haaren
2018-01-30 23:53 ` Thomas Monjalon
2018-01-31 13:53 ` Ananyev, Konstantin [this message]
2018-01-31 14:31 ` Thomas Monjalon
2018-01-31 14:54 ` Van Haaren, Harry
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