| Message ID | 20250417072839.711-1-rakie.kim@sk.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | Enhance sysfs handling for memory hotplug in weighted interleave | expand |
On Thu, 17 Apr 2025 16:28:34 +0900 Rakie Kim <rakie.kim@sk.com> wrote: > These patches have been tested under CXL-based memory configurations, > including hotplug scenarios, to ensure proper behavior and stability. > > mm/mempolicy.c | 240 ++++++++++++++++++++++++++++++------------------- > 1 file changed, 148 insertions(+), 92 deletions(-) > > base-commit: 8ffd015db85fea3e15a77027fda6c02ced4d2444 > -- To Andrew I sincerely apologize for causing repeated inconvenience. The series of patches version v8 that was merged into -mm, mm-new today needs additional corrections. Link: https://lore.kernel.org/all/6800742de6315_130fd2949c@dwillia2-mobl3.amr.corp.intel.com.notmuch/ Therefore, I have updated a new version v9, in which the problems have been addressed. I would greatly appreciate it if you could drop the existing v8 and replace it with the new version v9. Below is the information regarding the v8 patch series that needs to be dropped. Once again, I truly apologize for the inconvenience. <1> The patch titled: Subject: mm/mempolicy: fix memory leaks in weighted interleave sysfs Filename: mm-mempolicy-fix-memory-leaks-in-weighted-interleave-sysfs.patch <2> The patch titled: Subject: mm/mempolicy: prepare weighted interleave sysfs for memory hotplug Filename: mm-mempolicy-prepare-weighted-interleave-sysfs-for-memory-hotplug.patch <3> The patch titled: Subject: mm/mempolicy: support memory hotplug in weighted interleave Filename: mm-mempolicy-support-memory-hotplug-in-weighted-interleave.patch Rakie
On Thu, 17 Apr 2025 17:10:08 +0900 Rakie Kim <rakie.kim@sk.com> wrote: > I sincerely apologize for causing repeated inconvenience. The series of > patches version v8 that was merged into -mm, mm-new today needs > additional corrections. > Link: https://lore.kernel.org/all/6800742de6315_130fd2949c@dwillia2-mobl3.amr.corp.intel.com.notmuch/ > Therefore, I have updated a new version v9, in which the problems have > been addressed. No probs, this is why mm.git workflow (mm-new -> mm-unstable -> mm-stable -> mainline) operates as it does - to easily permit revisions and replacements as patches move towards their final state. Please note that I added a cc:stable to your [1/N] patch - sysfs leaks should be fixed in earlier kernels. I considered this to be low priority - if it's higher priority than this patch should best have been separated from the series, so it can take a different merge path from the other patches.
Andrew Morton wrote: > On Thu, 17 Apr 2025 17:10:08 +0900 Rakie Kim <rakie.kim@sk.com> wrote: > > > I sincerely apologize for causing repeated inconvenience. The series of > > patches version v8 that was merged into -mm, mm-new today needs > > additional corrections. > > Link: https://lore.kernel.org/all/6800742de6315_130fd2949c@dwillia2-mobl3.amr.corp.intel.com.notmuch/ > > Therefore, I have updated a new version v9, in which the problems have > > been addressed. > > No probs, this is why mm.git workflow (mm-new -> mm-unstable -> > mm-stable -> mainline) operates as it does - to easily permit revisions > and replacements as patches move towards their final state. > > Please note that I added a cc:stable to your [1/N] patch - sysfs leaks > should be fixed in earlier kernels. I considered this to be low > priority - if it's higher priority than this patch should best have > been separated from the series, so it can take a different merge path > from the other patches. The risk of leak is low because it only appears to trigger if setup fails. Setup only fails due to -ENOMEM which is unlikely to happen from a late_initcall() when memory pressure is low.
Andrew Morton wrote: > On Thu, 17 Apr 2025 17:10:08 +0900 Rakie Kim <rakie.kim@sk.com> wrote: > > > I sincerely apologize for causing repeated inconvenience. The series of > > patches version v8 that was merged into -mm, mm-new today needs > > additional corrections. > > Link: https://lore.kernel.org/all/6800742de6315_130fd2949c@dwillia2-mobl3.amr.corp.intel.com.notmuch/ > > Therefore, I have updated a new version v9, in which the problems have > > been addressed. > > No probs, this is why mm.git workflow (mm-new -> mm-unstable -> > mm-stable -> mainline) operates as it does - to easily permit revisions > and replacements as patches move towards their final state. Perhaps something like the update below to the mm-commits@ notification template, because I think folks misread early acceptance into mm-new as "Hooray, I'm done!" instead of "Ok, now more review might be inbound because Andrew has put this patch on his radar, but I am not done until this hits mm-stable". --- --- template.orig 2025-04-17 15:48:49.913337459 -0700 +++ template 2025-04-17 15:51:57.294617179 -0700 @@ -1,10 +1,16 @@ The patch titled Subject: $subject has been added to the -mm mm-new branch. Its filename is $patch_name This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/$patch_name This patch will later appear in the mm-new branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm + +Note, mm-new is a provisional staging ground for work-in-progress +patches, and acceptance into mm-new is a notification for others take +notice and finish up reviews. Please do not hesitate to respond to +review feedback and post updated versions to replace or incrementally +fixup patches in mm-new. --- ...otherwise, documentation like that would be good fodder for a mm "maintainer profile" [1]. [1]: https://docs.kernel.org/process/maintainer-handbooks.html
On Thu, 17 Apr 2025 15:41:30 -0700 Dan Williams <dan.j.williams@intel.com> wrote: > Andrew Morton wrote: > > On Thu, 17 Apr 2025 17:10:08 +0900 Rakie Kim <rakie.kim@sk.com> wrote: > > > > > I sincerely apologize for causing repeated inconvenience. The series of > > > patches version v8 that was merged into -mm, mm-new today needs > > > additional corrections. > > > Link: https://lore.kernel.org/all/6800742de6315_130fd2949c@dwillia2-mobl3.amr.corp.intel.com.notmuch/ > > > Therefore, I have updated a new version v9, in which the problems have > > > been addressed. > > > > No probs, this is why mm.git workflow (mm-new -> mm-unstable -> > > mm-stable -> mainline) operates as it does - to easily permit revisions > > and replacements as patches move towards their final state. > > > > Please note that I added a cc:stable to your [1/N] patch - sysfs leaks > > should be fixed in earlier kernels. I considered this to be low > > priority - if it's higher priority than this patch should best have > > been separated from the series, so it can take a different merge path > > from the other patches. > > The risk of leak is low because it only appears to trigger if setup > fails. Setup only fails due to -ENOMEM which is unlikely to happen from > a late_initcall() when memory pressure is low. Oh, OK, thanks. I added the above paragraph to the changelog and removed the cc:stable. Generally, we assume that -ENOMEM doesn't happen in __init code. If it does, the kernel is totally messed up anyway)
The following patch series enhances the weighted interleave policy in the memory management subsystem by improving sysfs handling, fixing memory leaks, and introducing dynamic sysfs updates for memory hotplug support. Changes from v8: https://lore.kernel.org/all/20250416113123.629-1-rakie.kim@sk.com/ - Updated lock usage during sysfs entry creation - Fixed sysfs removal warning triggered during exception handling paths Changes from v7: https://lore.kernel.org/all/20250408073243.488-1-rakie.kim@sk.com/ - Refactored error handling paths to remove unnecessary `goto` usage - Renamed unclear variables and functions for better readability Changes from v6: https://lore.kernel.org/all/20250404074623.1179-1-rakie.kim@sk.com/ - Removed redundant error handling in MEM_OFFLINE case Changes from v5: https://lore.kernel.org/all/20250402014906.1086-1-rakie.kim@sk.com/ - Added lock protection to sensitive sections Changes from v4: https://lore.kernel.org/all/20250401090901.1050-1-rakie.kim@sk.com/ - Added missing `kobject_del()` when removing a kobject - Extended locking coverage to protect shared state Changes from v3: https://lore.kernel.org/all/20250320041749.881-1-rakie.kim@sk.com/ - Added error handling for allocation and cleanup paths - Replaced static node attribute list with flexible array - Reorganized four patches into three based on their functional scope Changes from v2: https://lore.kernel.org/all/20250312075628.648-1-rakie.kim@sk.com/ - Clarified commit messages - Refactored to avoid passing the global structure as a parameter Changes from v1: https://lore.kernel.org/all/20250307063534.540-1-rakie.kim@sk.com/ - Fixed memory leaks related to `kobject` lifecycle - Refactored sysfs layout for hotplug readiness - Introduced initial memory hotplug support for weighted interleave ### Introduction The weighted interleave policy distributes memory allocations across multiple NUMA nodes based on their performance weight, thereby optimizing memory bandwidth utilization. The weight values are configured through sysfs. Previously, sysfs entries for weighted interleave were managed statically at initialization. This led to several issues: - Memory Leaks: Improper `kobject` teardown caused memory leaks when initialization failed or when nodes were removed. - Lack of Dynamic Updates: Sysfs attributes were created only during initialization, preventing nodes added at runtime from being recognized. - Handling of Unusable Nodes: Sysfs entries were generated for all possible nodes (`N_POSSIBLE`), including memoryless or unavailable nodes, leading to sysfs entries for unusable nodes and potential misconfigurations. ### Patch Overview 1. [PATCH 1/3] mm/mempolicy: Fix memory leaks in weighted interleave sysfs - Ensures proper cleanup of `kobject` allocations. - Adds `kobject_del()` before `kobject_put()` to clean up sysfs state correctly. - Prevents memory/resource leaks and improves teardown behavior. - Ensures that `sysfs_remove_file()` is not called from the release path after `kobject_del()` has cleared sysfs state, to avoid potential inconsistencies and warnings in the kernfs subsystem. 2. [PATCH 2/3] mm/mempolicy: Prepare weighted interleave sysfs for memory hotplug - Refactors static sysfs layout into a new `sysfs_wi_group` structure. - Makes per-node sysfs attributes accessible to external modules. - Lays groundwork for future hotplug support by enabling runtime modification. 3. [PATCH 3/3] mm/mempolicy: Support memory hotplug in weighted interleave - Dynamically adds/removes sysfs entries when nodes are online/offline. - Limits sysfs creation to nodes with memory, avoiding unusable node entries. - Hooks into memory hotplug notifier for runtime updates. These patches have been tested under CXL-based memory configurations, including hotplug scenarios, to ensure proper behavior and stability. mm/mempolicy.c | 240 ++++++++++++++++++++++++++++++------------------- 1 file changed, 148 insertions(+), 92 deletions(-) base-commit: 8ffd015db85fea3e15a77027fda6c02ced4d2444