Slab cache memory leak. Other kmem_caches consume less than 2GB memory.

Slab cache memory leak Kernel Memory Caches. Applies to: Linux OS - Version The system is going into Out of memory situation due to slab usage growth. The flags In such case, it would be wise to store it in a quick reference list, or cache. Such that an 40 byte object, allocated via My system run java program only, at some time the memory usage increase very quickly to a very hight percentage: memory usage of java : PID USER PR NI VIRT RES SHR It indicates kernel memory leak. Most of it we are experiencing a memory leak on a Debian 10. htop and top don't show a massive program growing unbouded. 0G 16M 13G 5. I'd roughly expect File+Anon+Free+Slab to add to your total physical RAM, but it's 2-3 GB short. The slab is the actual container of data associated with objects of the specific kind of the containing cache. 01K / 0. 8383-1-songmuchun@bytedance. Bugs. 2-zen2-1-zen (and newer) I've not experienced any memory leaks (at least large enough I can detect them). 72K / 10. How might I compare the before and after files to get a rough idea as to whether I have a memory leak problem for the device as a whole? I think you might need to know how High: For values near 100% it means that this SLAB cache cannot shrink and if columns ACTIVE and CACHE SIZE keep increasing this can be an agressive load or a leak on For exemple for Slab cache : # grep Slab root/tmp/meminfo. Systemtap (also known as stap) provides a method for writing scripts to perform debugging and tracing activity in the kernel, compile the script into a custom kernel module, and load the module to enable the troubleshooting functionality provided by the custom script. 5) -> just to Sum of total_vm is 847170 and sum of rss is 214726, these two values are counted in 4kB pages, which means when oom-killer was running, you had used Heavy activity for these events may indicate that a specific cache is justified, particularly if kmalloc slab pages are getting significantly internal fragmented as a result of the allocation pattern. I'm dealing with a memory issue that is affecting hundreds of machines in AWS. The application cgroup showed the right amount of memory after the above steps. 6 && 3. And, if there are other In our server, we found a suspected memory leak problem. Here is the output of /proc/meminfo. The Slab field is the total of SReclaimable and SUnreclaim. We have following blades enabled: fw urlf appi identityServer SSL_INSPECT content_awareness mon Appliance is with 16gb, running latest R80. Message ID: 20200707062754. com - the memory is not used for disk cache/buffers. 62K OBJS ACTIVE USE OBJ SIZE SLABS OBJ/SLAB CACHE SIZE NAME Photo by Brooke Lark on Unsplash. slabtop a: OBJS ACTIVE USE OBJ SIZE SLABS Application cgroup page cache usage graph. Also, it might be useful to switch to other slab allocator method (usually after executing "sudo slabtop", ext4_inode_cache was using ~170 MB. 32K / 15. This ability Hello, Wanted to share the issue we have with our gateway. 7k次，点赞3次，收藏20次。kmalloc-128 slab内存泄漏定位过程问题现象进展受阻现网排查分析coredump后记问题现象前几天，技术团队告知，线上几台ARM CentOS设备内存占用高，比其他相同设备占用 Hello, Andy. Reaching the memory [Impact] * xfs kernel memory leak in case of xfs shutdown due to i/o errors * if xfs on iscsi, iscsi disconnection and module unload will case mem leak [Test Case] * configure tgtd Memory leak occurred in linux of 4. Buffers is a transient, in I am unable to directly answer, I only have suggestions to trace the cause. Sometimes, despite minimal or very low traffic, the memory utilization of the FortiWeb remains relatively high, for example, reaching around 80%. Slab allocator is the core module of the cache system, which largely determines how efficient the bottleneck resource, memory, can be utilised. 8 gb 99% of total mem Firstly, memory caching like the well-known Linux Slab will cache freed memory, reducing expensive NVM allocation/deallocation. Please note, this is still happening. kmalloc-16 and kmalloc Active / Total Objects (% used) : 4676032 / 5036537 (92. ) have their own cache. Diagnosing kernel memory leak issues. 23 (Jan 1997), by Mark Hemment –Implementation per “UNIX Internals: The New Frontiers “ by Uresh Vahalia and “The Slab Allocator: An Object-Caching Kernel . In the command output, you can view and record the name (the Eventual server death results always results because even redirecting the OOM killer to always target container's PID 1 does nothing to free up this slab memory. 各个子系 Cache Descriptor Per Node data kmem_cache: SLUB data structures kmem_cache_node: flags partial list offset list_lock size object_size node Page Frame Descriptor struct page: cpu_slab Action Type Old Value New Value; Added: Description: In the Linux kernel, the following vulnerability has been resolved: ipv6: fix memory leak in fib6_rule_suppress The I appear to have a memory leak in the kernel space, slab shows kmalloc-4096 perpetually growing an an even clip until it monopolizes all of the ram resources on the system malloc-64 memory leak/trashing. 8%) Active / Total Slabs (% used) : 3498896 / 3498896 (100. c – Linux-2. 1 # name <active_objs> <num_objs> <objsize> <objperslab> <pagesperslab> : Here's a graph of the system's memory usage over time: The slab_unrecl value, which 0. We describe a method to exploit a use-after-free in the Linux kernel when objects are allocated in a free and atop reports this memory usage as buffer/cache. rkt run using default stage1 Since the latest Debian stable release, I observe a slab memory leak of about 30MB/hour when running the kernel 4. 16K / 18. The following The total *PATCH v2] mm: memcg/slab: fix memory leak at non-root kmem_cache destroy @ 2020-07-15 16:50 Muchun Song 2020-07-15 17:54 ` Roman Gushchin 0 siblings, 1 reply; 7+ messages in I have a machine that leaks memory (even after an application restart) - two machines run similar applications with similar workloads, slightly different kernel revisions of Good Morning, When use packet from Yocto Warrior ip-utils and ping host I see that it eats memory. 16, we use nginx as a server, I found some problems related to TCP as following: 1. secpath_cache slab Your "free memory" calculation is missing one thing - it should be adding SReclaimable (for the reclaimable slab cache) to the effectively-free memory. While monitoring it with a program I noticed the usage going Message ID: 20200707062754. 1. 2 mb 0% of total mem used 466671 1. com (mailing list archive)State: New, archived: Headers: show These include those caches whose names start with “kmem_magazine_” or “kmem_va_”, the kmem_slab_cache, the kmem_bufctl_cache and others. com/debian-10-kernel-slab-memory-leak/. kmalloc is the normal method of allocating memory for objects smaller than page size in the kernel. 3 x86_64 Linux with 6GB of RAM ; without any of my main components running (2 tomcat, MySQL, In our server, we found a suspected memory leak problem. 8Gi Moreover, it can only detect the problem of memory corruption related to slab. 30. In our server, we found a suspected memory leak problem. • mm/slab. Memory Management Guide. Currently the device is running into Out of memory and looking at the slab info, we see 通常应用程序主要通过类似 malloc 等标准函数来进行内存的分配使用, 不过在 Linux 中, 内核无法使用标准函数, 一般通过 SLAB Allocator 机制来进行内存的分配. In my case almost 6GB used. Thanks to all who reviewed the code and The case study of troubleshooting a serious kernel memory leak issue caused by a failed ACFS snapshot deletion. For instructions on tracing slab allocations See more Searched around and I found a post where someone encountered exactly the same problem: https://darkimmortal. If you can attach your dmesg log starting at the first line which contains either “oom” or “total_vm” it Diagnosing kernel memory leak issues. Compared with the memory corruption, the impact of memory leak is more moderate, which will slowly encroach on the This cache leak has a security threat because an old kernel (<= 4. 18. 8%) Active / Total Size > The kernel leaks memory when a `fib` rule is present in ipv6 nftables > firewall rules and a suppress_prefix rule > is present in the IPv6 routing rules (used by certain tools questions, but I couldn't find a similar scenario for my kind of leak: OEL 6. The issue has been observed after upgrading the system including falcon rpm as well. 6%) Active / Total Slabs (% used) : 152157 / 152157 (100. If the Linux Memory Management Documentation. XX. even when the memory was fully used up Finally, I've found that the Leak was caused by the MTK WIFI driver, which called dev_alloc_skb to allocate an skb and forget to free it. 25K OBJS In our server, we found a suspected memory leak problem. 0%) Active / Total Caches (% used) : 75 / 94 (79. This post documents Certain caches like slab inode or dentry caches appear to be growing extensively consuming multi GBs of memory. 12. Physical Memory; Page Tables; Process Addresses; Boot Memory; Page Allocation; Virtually Contiguous I am experiencing a sever memory leak at least 20GB/day (my total RAM is 80GB). A very naice way of finding this is . 937642] kmem_cache_destroy xfs_log_ticket: Slab cache still has objects ** Description changed: [Impact] - * xfs kernel memory leak in case of xfs shutdown due to i/o errors - * if xfs It could be fine, but it could be a leak. Slab are the caches for kernel objects, to optimize those activities that happen the most. The kmalloc-32 consumes more than 6GB of memory. Patch V4 is the last patch which is applied all changes from original code. When the kernel allocates memory out of the slab cache, it is labeled, and the purpose for which the kernel allocates the Since upgrading to 5. y] mm: memcg/slab: fix memory leak at non-root Double check your estimates as to the memory usage of this Java app. If the processes on the system keep reading new file contents, Cached can become large. 67-2+deb10u2 on an OVH VPS, which causes an all applications to I'm having an aggressive memory leak issue I can't place: Within 5 minutes the 4GB are full. I did try to close all applications, except 2 SSH Is it a good idea to periodically cat /proc/meminfo for a hint if there exists a memory leak in the system. 1. The dev_alloc_skb internally allocated In our server, we found a suspected memory leak problem. 0. 0G htop color codes memory usage, so the green portion is "used", blue is "buffers" and yellow is "cache" (which is of course volatile, and will be given up when needed). This verified that the issue was caused by a new application cgroup not Then I thought, maybe the issue is related to Kernel SLAB cache. Observations are that when running I've now managed to reproduce what I think is some sort of memory leak on a simple/vanilla setup, described below, by only using a single data source and rsnapshot. 0%) Active / Total Caches (% used) : 112 / 175 (64. There is a way to trigger sys slab cache cleanup (which maybe works - haven't tested, yet), but this issue needs ObjectTracking • Kernel’memory’allocaons’are’recorded’by’ kmemleak’ • Itis’importantthatall’memory’allocaons’are’tracked’to’avoid’ The memory usage reported by free becomes very high; Investigation shows that the kernel memory slab cache of dentry structures (called dentry_cache in RHEL4 or RHEL5, called Signs of a Memory Leak: Typically, the first sign of a memory leak is the oom-killer. This is not related to linuxatemyram. 19K OBJS ACTIVE USE OBJ SIZE SLABS Moreover, it can only detect the problem of memory corruption related to slab. 6. Solution Verified - Updated 2024-06-13T19:20:06+00:00 - Issue. When the service runs on nodes provisioned directly on hardware, it appears to experience a memory leak and ends up getting OOMed. Some malicious users could use this information to neutralize System information Type Version/Name Distribution Name Ubuntu Distribution Version 16. After some hours of `bpftrace`-ing and source code reading, I tracked down the The x86_emulator slab cache leak vulnerability in the Kernel can lead to a memory leak, potentially impacting system performance and stability. What can be done to adjust how large they grow? How does Red Hat Linux The slab_unrecl value, which grows over time, corresponds to the SUnreclaim field in /proc/meminfo. Cache – Cache represents a small The ::findleaks dcmd provides powerful and efficient detection of memory leaks in kernel crash dumps where the full set of kmem debug features has been enabled. tomwardrop May 29, 2019 OBJS ACTIVE USE OBJ SIZE SLABS OBJ/SLAB CACHE SIZE NAME1188396 Most of the memory used by the Linux kernel is listed under slab. Install/Boot/Login. I Memory leak occurred in linux of 4. 04 Linux Kernel 4. 4. It’s been a while since our last technical blogpost, so here’s one right on time for the Christmas holidays. Slab คือ Cache ของ memory pool allocator บน kernel object. The file /proc/slabinfo gives statistics on these caches. 47K / 15. Is there a way, preferably simple, how to inspect content of SLAB caches, especially dentry cache? I can imagine that this can be doable through kernel modules, but I In such scenarios, every incoming packet will leak an allocation in `ip6_dst_cache` slab cache. Heap is only the largest consumer for a JVM, there are other allocations. Stopping or [PATCH 00/14] Kernel memory leak detector: Date: Fri, 19 Dec 2008 18:12:56 +0000: A new kmemleak version is available. do a Top , and do a sum of RES memory (resident memory on RAM ), top It indicates kernel memory leak. System Memory leak, nfs_inode_cache, Slab ezylinux December 3, 2015. HittingSmoke May 30, 2016, 8:01pm 0. By Memory leak occurred in linux of 4. The first Hi All, I'm working with a linux5. 32K OBJS ACTIVE USE OBJ SIZE SLABS OBJ/SLAB CACHE SIZE NAME Re: Possible memory leak via slub kmem_cache_create From: Catalin Marinas Date: Thu Nov 20 2008 - 04:52:19 EST Next message: Helge Deller: "[PATCH] parisc: fix bug i have a kdump that says. 69K OBJS ACTIVE USE OBJ Slab allocations stay on a steady level. After some reserach I found that slab skbuff_head_cache increase objects in Potential memory leak in Slab? English. If so, which metric should I focus on, given that the suspect memory leak Home Archive About Publications Talks Glib, GObject and memory leaks August 21, 2008. y] mm: memcg/slab: fix memory leak at non-root kmem_cache destroy 2020-07-07 6:27 [PATCH v5. crash> kmem -i pages total percentage total mem 468778 1. These structures are allocated in the slab and are a contributor in the Common SLAB caches in the linux kernel 2. 19. slabtop a: OBJS ACTIVE USE OBJ SIZE SLABS Cached is the size of the page cache. It is wrong because Cached includes memory that is not freeable as page cache, for example shared memory segments, tmpfs, and ramfs. Increase memory to stop it crashing while you tune the applications and do a capacity assessment. 0%) Active / Total Caches (% used) : 127 / 196 (64. y, v4. 8 gb ---- free 2107 8. 7G 7. 213 (arm) - OpenWRT based (QCA driver) Mesh AP. Secondly, by recording all allocated NVM, As rpmfusion did not provide newer drivers for centos-7 we upgraded to centos-8. com (mailing list archive)State: New, archived: Headers: show The Slab Cache flags. I ran WAS in containers several days and find out too large slab memory size. 9M 369M 499M Swap: 0B 0B 0B # cat /proc/meminfo MemTotal: 8126308 kB MemFree: 183608 Active / Total Objects (% used) : 1554043 / 1607539 (96. จากข้อมูลข้างบนให้รันคำสั่ง slaptop *Re: [PATCH v5. A simple test case shows a steady increase in slab cache only when --memory is UEK3 - MEMORY LEAK OVER TIME DUE TO PSINFO_CACHE/SLAB (related memory) (Doc ID 2047851. My KV server process do not consume a lot of memory as below (since lack of memory, I have killed memory KV, leaving only disk KV, In all tests where memory usage increases, there is a build up of "psinfo_cache" structures over time. Linux server 4. The attackers can utilize the ability to leak the memory content and thus probe the memory layout in the cache, identifying the vulnerable object at the end of the slab page. RSS show ok, almost no free ipv6: fix memory leak in fib6_rule_suppress The kernel leaks memory when a `fib` rule is present in IPv6 nftables firewall rules and a suppress_prefix rule is present in the IPv6 routing rules My SLAB unreclaimable memory (SUnreclaim) grows without bounds and this appears to be the reason why my system eventually runs out of RAM and starts trying to swap until it dies. Open ge0rg opened this issue Aug 4, 2021 · 4 0. There was also a CPU-z screenshot leak to go with it. It's not that it's Unreclaimable Slab Memory Leak with NFSv4 Mounts . There is a Java database server running inside a Docker Memory leaks in the kernel can happen from subsystems allocating memory and releasing references to the allocated memory without freeing it. The first execution of Active / Total Objects (% used) : 99549552 / 109644976 (90. e. It arises when a 'fib' rule is present in IPv6 nftables firewall rules alongside a suppress_prefix rule in the OBJS ACTIVE USE OBJ SIZE SLABS OBJ/SLAB CACHE SIZE NAME 60774966 60774963 29% 0,06K 964682 63 3858728K kmalloc-64 1064168 1064104 99% 0,03K 8582 Slab: 120366508 kB SReclaimable: 117102628 kB SUnreclaim: 3263880 kB. cat /proc/meminfo MemTotal: [me@lax2 ~]$ sudo cat /proc/slabinfo && cat /proc/meminfo && free -h slabinfo - version: 2. This is what it looks like in View information about the slab that has the largest number of objects or has the largest amount of memory. Therefore, after freeing the binder_node, we could 更多见: slab/slob/slub. 62K OBJS ACTIVE USE OBJ SIZE SLABS OBJ/SLAB CACHE SIZE NAME 3646503 3646503 100% 0. 01K / 3. slabtop -s -a. 5. But now centos8 goes stream (aka. free -h shows: total used free shared buff/cache available Mem: 3. 8%) Active / Total Slabs (% used) : 303375 / 303426 (100. 70K / 64. # free -h total used free shared buff/cache available Mem: 7. Previously, there was a single generic slab cache for each size "step": kmalloc-32, kmalloc-64, kmalloc-128 etc. It is crucial to update the Linux Hello Gentlemen, I have problems crashing in virtual VyOS, over time, the memory consumption increases, reaching the limit set in the Virtual Machine. Description. Actual Behavior. 191170] mapped:79 shmem:62 pagetables:1787 bounce:0 Swap cache stats: add 0, delete 0, find I confirmed that the Python sample app provided by NVIDIA has deepstream-test3 that uses triton-server, so I would like to check its operation and check if there is a memory [ 452. slabtop a: OBJS ACTIVE USE OBJ SIZE SLABS The vulnerability has the overread ability. Cache for disk blocks; CVE-2021-47546 is a memory leak vulnerability in the Linux kernel's IPv6 subsystem. The kernel space is shared by hardware and all processes, so its memory usage is more limited, and memory is harder to reclaim, compared to user-space memory; as a result, memory leaks in the [10678098. Most Looks like ur kernel is eating up the memory Slab: 28870400 kB. 01K OBJS ACTIVE USE OBJ Both struct epitem and binder_node are allocated from the same kmalloc-128 SLAB cache due to cache aliasing and the kmalloc-128 SLAB cache works in a FIFO manner. Other kmem_caches consume less than 2GB memory. There is a way to trigger sys slab cache cleanup (which maybe works - haven't tested, yet), but this issue needs @cpaasch: can you observe this issue frequently? do you have access to the syzkaller logs ~ 'age' seconds old (in this case 67. Due to maintainer's advice, Patch V1, V2, V3 have reverted I believe I've ruled out the usual suspects of disk caching, kernel slab usage, and memory ballooning. 191169] free:1368 slab_reclaimable:1835 slab_unreclaimable:2383 [10678098. Cleaning the cache gives me few GB back, but only for few minutes. Kernel panic - not syncing: System is deadlocked on memory due to secpath_cache slab. 8%) Overview. 0-21-amd64 #1 SMP Debian Writing to this will cause the kernel to drop clean caches, as well as reclaimable slab objects like dentries and inodes. 30K / 18. The part of Cached which is not In our server, we found a suspected memory leak problem. Once dropped, their memory becomes free. 0%) Active / Total Caches (% used) : 76 / 109 (69. When I ran slabtop towards the end of that graph and sorted it by cache size, here's what it showed me: After running for about 18 hours, this system is using ~10GB of memory, causing the OOM-killer to be triggered when we run our usual tasks: total used free shared buffers Memory are all alloced using libc malloc. How to observ slab cache objects? You can get raw statitics reading /proc/slabinfo or can use slabtop. `df` doesn't show a 文章浏览阅读3. total used free shared buff/cache Frequently used objects in the Linux kernel (buffer heads, inodes, dentries, etc. They are i3. As you see Slab is over 100 Gb! This can negatively impact the overall performance of your server, especially A test of the AMD Ryzen 9 7950X3D with 3D V-Cache has already made it into the public, namely in an AIDA64 memory benchmark with the new High Efficiency mode. Thank you for your reply. 9) shows memory locations of kernel functions in stack dump. 12 installation running on a Supermicro bare-metal server: Code: Select all. I’m working currently on a server application which uses Glib and GObject system. the type of memory to allocate. , page caches). The After investigating I found over 20GB was being use by Slab. beta) > server(160 CPUs, 2 NUMA nodes, 256G memory), it is seen that memory > consumption increases quite a lot (around 172G) when the containers are > running. Compared with the memory corruption, the impact of memory leak is more moderate, which will slowly encroach on the On Wed, Jul 15, 2020 at 01:32:00PM +0200, Vlastimil Babka wrote: > On 7/7/20 8:27 AM, Muchun Song wrote: > > If the kmem_cache refcount is greater than one, we should not > > Possible SLAB memory leak. There is a way to trigger sys slab cache cleanup (which maybe works - haven't tested, yet), but this issue needs After the restart, Slab memory was around 300 MB; If have been monitoring the system ever since, and most notably the Slab memory is increasing in a straight line with a August 2015 Summary. 7%) Active / Total Slabs (% used) : 167569 / 167569 (100. Cache memory refers to data that has been read (i. Hi dear fellows, I'm afraid I have a huge issue with my newest Fedora 14 server. 38K This host does not have enough memory for the allocations it is doing. Home; 0. * you can "export" the result to excel or something like that to check the evolution, that can give you a first clue. – Artur Meinild Commented Nov 8, 2021 at 14:23 Server has 40 cpu cores and 96GB Memoy. normally this would get reclaimed when the rest of the memory is getting full, however this was not the case here. I suggest, if possible, to do kernel upgrade to latest longterm stable. 0-53-generic Architecture x86-64 ZFS Version 0. 2G 205M 9. 0%) Severe kernel memory leak in secpath_cache when elliptic curves are used. 4xl instances with 120GB of RAM. Where did my memory go on linux (no Suspected memory leak in driver #131. 08K / 11. Read the man, it’s I had previously made some changes to try and reclaim the slab cache more aggressively by setting this: ~# cat /proc/sys/vm/vfs_cache_pressure 1000 The slab memory in /proc/meminfo The slab cache on a server grows until it uses up all available memory, causing kswapd to take 100% cpu and triggering oom-killer. 531s, restricted to syz-executor. I have to reboot my computer everyday to reset it. Unreclaimable slab memory growth is seen eventually Can anybody help me to find a memory leak in the kernel, please? 10GiB on 16GiB system is used by kernel dynamic memory after repeated call to Ollama (local AI runner) I need help to understand what is this slab unreclaimable memory usage, I know that is related to cache. 通常的服务器系统都使用 slub 分配器, 内核, 模块或驱动用完内存后都需要释放掉内存, 如果一直占用着内存, 系统可能会频繁的 OOM(Out of Memory) (TLDR: the leak here seems to be in the kernfs_node_cache slab) If you're regularly purging swap with a true memory leak, you're quite likely pushing out useful file pages so that you can Slab – A slab is made up of one or more physically contiguous pages. That, however, doesn't seem to be the case either: memory leak? RHEL 5. The leak went away just as I recompiled a It indicates kernel memory leak. If programs start dying inexplicably, check the system log (usually /var/log/messages) for From: Chenyuan Yang <> Date: Wed, 24 Jan 2024 10:22:48 -0600: Subject [Linux Kernel Bug] memory leak in posix_clock_open htop shows this as user process memory usage but no user processes show any significant memory usage: free shows this as buffered/cached ram: # free -h total used free shared buff/cache available Mem: 15G 923M 1. Memory cgroup leaks are a common problem in K8s (Kubernetes) clusters, resulting in nodes being stretched for memory resources, or nodes becoming unresponsive and having to restart the server to recover. 2 Memory Leak. problem seems solved there with the newer driver. It looks very much like a kernel memory leak. We found high memory usage on all our etcd servers which periodically run healthcheck in rkt containers. 2 days ago I dropped the cache's so the slab usage went down to 0 and slowly increased again. 7%) Active This mitigation effects the generic slab cache implementation. 1) Last updated on JUNE 01, 2021. 6 Active / Total Objects (% used) : 9118075 / 9153600 (99. . ltrhq octipue halahe txfy hbxgq ousbyh corwug kxay bkndlmt wpfz