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 --- Documentation/ABI/testing/sysfs-kernel-mm-ksm | 61 +++++++++++++++++++++++++++ 1 file changed, 61 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-kernel-mm-ksm (limited to 'Documentation/ABI/testing/sysfs-kernel-mm-ksm') diff --git a/Documentation/ABI/testing/sysfs-kernel-mm-ksm b/Documentation/ABI/testing/sysfs-kernel-mm-ksm new file mode 100644 index 000000000..6041a025b --- /dev/null +++ b/Documentation/ABI/testing/sysfs-kernel-mm-ksm @@ -0,0 +1,61 @@ +What: /sys/kernel/mm/ksm +Date: September 2009 +KernelVersion: 2.6.32 +Contact: Linux memory management mailing list +Description: Interface for Kernel Samepage Merging (KSM) + +What: /sys/kernel/mm/ksm/full_scans +What: /sys/kernel/mm/ksm/pages_shared +What: /sys/kernel/mm/ksm/pages_sharing +What: /sys/kernel/mm/ksm/pages_to_scan +What: /sys/kernel/mm/ksm/pages_unshared +What: /sys/kernel/mm/ksm/pages_volatile +What: /sys/kernel/mm/ksm/run +What: /sys/kernel/mm/ksm/sleep_millisecs +Date: September 2009 +Contact: Linux memory management mailing list +Description: Kernel Samepage Merging daemon sysfs interface + + full_scans: how many times all mergeable areas have been + scanned. + + pages_shared: how many shared pages are being used. + + pages_sharing: how many more sites are sharing them i.e. how + much saved. + + pages_to_scan: how many present pages to scan before ksmd goes + to sleep. + + pages_unshared: how many pages unique but repeatedly checked + for merging. + + pages_volatile: how many pages changing too fast to be placed + in a tree. + + run: write 0 to disable ksm, read 0 while ksm is disabled. + + - write 1 to run ksm, read 1 while ksm is running. + - write 2 to disable ksm and unmerge all its pages. + + sleep_millisecs: how many milliseconds ksm should sleep between + scans. + + See Documentation/mm/ksm.rst for more information. + +What: /sys/kernel/mm/ksm/merge_across_nodes +Date: January 2013 +KernelVersion: 3.9 +Contact: Linux memory management mailing list +Description: Control merging pages across different NUMA nodes. + + When it is set to 0 only pages from the same node are merged, + otherwise pages from all nodes can be merged together (default). + +What: /sys/kernel/mm/ksm/general_profit +Date: April 2023 +KernelVersion: 6.4 +Contact: Linux memory management mailing list +Description: Measure how effective KSM is. + general_profit: how effective is KSM. The formula for the + calculation is in Documentation/admin-guide/mm/ksm.rst. -- cgit v1.3.1