On Tue, Jul 30, 2024 at 7:44 PM Zhiguo Jiang <justinjiang@xxxxxxxx> wrote: > > The main reasons for the prolonged exit of a background process is the > time-consuming release of its swap entries. The proportion of swap memory > occupied by the background process increases with its duration in the > background, and after a period of time, this value can reach 60% or more. Do you know the reason? Could they be contending for a cluster lock or something? Is there any perf data or flamegraph available here? > Additionally, the relatively lengthy path for releasing swap entries > further contributes to the longer time required for the background process > to release its swap entries. > > In the multiple background applications scenario, when launching a large > memory application such as a camera, system may enter a low memory state, > which will triggers the killing of multiple background processes at the > same time. Due to multiple exiting processes occupying multiple CPUs for > concurrent execution, the current foreground application's CPU resources > are tight and may cause issues such as lagging. > > To solve this problem, we have introduced the multiple exiting process > asynchronous swap memory release mechanism, which isolates and caches > swap entries occupied by multiple exit processes, and hands them over > to an asynchronous kworker to complete the release. This allows the > exiting processes to complete quickly and release CPU resources. We have > validated this modification on the products and achieved the expected > benefits. > > It offers several benefits: > 1. Alleviate the high system cpu load caused by multiple exiting > processes running simultaneously. > 2. Reduce lock competition in swap entry free path by an asynchronous Do you have data on which lock is affected? Could it be a cluster lock? > kworker instead of multiple exiting processes parallel execution. > 3. Release memory occupied by exiting processes more efficiently. > > Zhiguo Jiang (2): > mm: move task_is_dying to h headfile > mm: tlb: multiple exiting processes's swap entries async release > > include/asm-generic/tlb.h | 50 +++++++ > include/linux/mm_types.h | 58 ++++++++ > include/linux/oom.h | 6 + > mm/memcontrol.c | 6 - > mm/memory.c | 3 +- > mm/mmu_gather.c | 297 ++++++++++++++++++++++++++++++++++++++ > 6 files changed, 413 insertions(+), 7 deletions(-) > mode change 100644 => 100755 include/asm-generic/tlb.h > mode change 100644 => 100755 include/linux/mm_types.h > mode change 100644 => 100755 include/linux/oom.h > mode change 100644 => 100755 mm/memcontrol.c > mode change 100644 => 100755 mm/memory.c > mode change 100644 => 100755 mm/mmu_gather.c Can you check your local filesystem to determine why you're running the chmod command? > > -- > 2.39.0 > Thanks Barry
