linux-kernel - [PATCH v5 05/21] selftests/resctrl: Ensure sibling CPU is not same as original CPU

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20210307145502.2916364-6-fenghua.yu@intel.com>
Date:   Sun,  7 Mar 2021 14:54:46 +0000
From:   Fenghua Yu <fenghua.yu@...el.com>
To:     "Shuah Khan" <shuah@...nel.org>, "Tony Luck" <tony.luck@...el.com>,
        "Reinette Chatre" <reinette.chatre@...el.com>,
        "Babu Moger" <babu.moger@....com>
Cc:     "linux-kselftest" <linux-kselftest@...r.kernel.org>,
        "linux-kernel" <linux-kernel@...r.kernel.org>,
        Fenghua Yu <fenghua.yu@...el.com>
Subject: [PATCH v5 05/21] selftests/resctrl: Ensure sibling CPU is not same as original CPU

From: Reinette Chatre <reinette.chatre@...el.com>

The resctrl tests can accept a CPU on which the tests are run and use
default of CPU #1 if it is not provided. In the CAT test a "sibling CPU"
is determined that is from the same package where another thread will be
run.

The current algorithm with which a "sibling CPU" is determined does not
take the provided/default CPU into account and when that CPU is the
first CPU in a package then the "sibling CPU" will be selected to be the
same CPU since it starts by picking the first CPU from core_siblings_list.

Fix the "sibling CPU" selection by taking the provided/default CPU into
account and ensuring a sibling that is a different CPU is selected.

Signed-off-by: Reinette Chatre <reinette.chatre@...el.com>
Signed-off-by: Fenghua Yu <fenghua.yu@...el.com>
---
Change Log:
v5:
- Move from v4's patch 8 to this patch as the fix patch should be first
  (Shuah).

 tools/testing/selftests/resctrl/resctrlfs.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/resctrl/resctrlfs.c b/tools/testing/selftests/resctrl/resctrlfs.c
index 4174e48e06d1..bc52076bee7f 100644
--- a/tools/testing/selftests/resctrl/resctrlfs.c
+++ b/tools/testing/selftests/resctrl/resctrlfs.c
@@ -268,7 +268,7 @@ int get_core_sibling(int cpu_no)
 	while (token) {
 		sibling_cpu_no = atoi(token);
 		/* Skipping core 0 as we don't want to run test on core 0 */
-		if (sibling_cpu_no != 0)
+		if (sibling_cpu_no != 0 && sibling_cpu_no != cpu_no)
 			break;
 		token = strtok(NULL, "-,");
 	}
-- 
2.30.1