From 27600805e62f800bacf990354632eae4e487d34c Mon Sep 17 00:00:00 2001 From: Yazen Ghannam Date: Thu, 3 Sep 2026 10:43:25 -0500 Subject: x86/amd_node: Fix PCI device reference counting in amd_smn_init() The local "root" pointer is a temporary variable used during the device search. Therefore, refcount related to the search iterators should be cleaned up after the search is complete. Use the __free() cleanup macro to ensure the refcount is decremented when the temporary pointer goes out of scope. Additionally, increment the refcount when caching a root pointer. This ensures the in-use refcount is separate from the temporary search refcounting. Finally, drop the redundant "root = NULL" before the second search loop. The pci_get_class() iterator always decrements the refcount of its "from" argument, so the first loop can only fall through with "root" already NULL. Fixes: 0a4b61d9c2e4 ("x86/amd_node: Fix AMD root device caching") Closes: https://sashiko.dev/#/patchset/20260806160159.230453-1-jason.andryuk%40amd.com Reported-by: Sashiko Assisted-by: LLM Signed-off-by: Yazen Ghannam Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Mario Limonciello (AMD) Cc: Link: https://patch.msgid.link/20260903154325.74343-1-yazen.ghannam@amd.com --- tools/perf/util/smt.c | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) create mode 100644 tools/perf/util/smt.c (limited to 'tools/perf/util/smt.c') diff --git a/tools/perf/util/smt.c b/tools/perf/util/smt.c new file mode 100644 index 000000000..650e804d0 --- /dev/null +++ b/tools/perf/util/smt.c @@ -0,0 +1,36 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include +#include "api/fs/fs.h" +#include "cputopo.h" +#include "smt.h" + +bool smt_on(void) +{ + static bool cached; + static bool cached_result; + int fs_value; + + if (cached) + return cached_result; + + if (sysfs__read_int("devices/system/cpu/smt/active", &fs_value) >= 0) + cached_result = (fs_value == 1); + else + cached_result = cpu_topology__smt_on(online_topology()); + + cached = true; + return cached_result; +} + +bool core_wide(bool system_wide, const char *user_requested_cpu_list) +{ + /* If not everything running on a core is being recorded then we can't use core_wide. */ + if (!system_wide) + return false; + + /* Cheap case that SMT is disabled and therefore we're inherently core_wide. */ + if (!smt_on()) + return true; + + return cpu_topology__core_wide(online_topology(), user_requested_cpu_list); +} -- cgit v1.3.1