- 11 Dec, 2023 11 commits
-
-
Peng Zhang authored
In dup_mmap(), using __mt_dup() to duplicate the old maple tree and then directly replacing the entries of VMAs in the new maple tree can result in better performance. __mt_dup() uses DFS pre-order to duplicate the maple tree, so it is efficient. The average time complexity of __mt_dup() is O(n), where n is the number of VMAs. The proof of the time complexity is provided in the commit log that introduces __mt_dup(). After duplicating the maple tree, each element is traversed and replaced (ignoring the cases of deletion, which are rare). Since it is only a replacement operation for each element, this process is also O(n). Analyzing the exact time complexity of the previous algorithm is challenging because each insertion can involve appending to a node, pushing data to adjacent nodes, or even splitting nodes. The frequency of each action is difficult to calculate. The worst-case scenario for a single insertion is when the tree undergoes splitting at every level. If we consider each insertion as the worst-case scenario, we can determine that the upper bound of the time complexity is O(n*log(n)), although this is a loose upper bound. However, based on the test data, it appears that the actual time complexity is likely to be O(n). As the entire maple tree is duplicated using __mt_dup(), if dup_mmap() fails, there will be a portion of VMAs that have not been duplicated in the maple tree. To handle this, we mark the failure point with XA_ZERO_ENTRY. In exit_mmap(), if this marker is encountered, stop releasing VMAs that have not been duplicated after this point. There is a "spawn" in byte-unixbench[1], which can be used to test the performance of fork(). I modified it slightly to make it work with different number of VMAs. Below are the test results. The first row shows the number of VMAs. The second and third rows show the number of fork() calls per ten seconds, corresponding to next-20231006 and the this patchset, respectively. The test results were obtained with CPU binding to avoid scheduler load balancing that could cause unstable results. There are still some fluctuations in the test results, but at least they are better than the original performance. 21 121 221 421 821 1621 3221 6421 12821 25621 51221 112100 76261 54227 34035 20195 11112 6017 3161 1606 802 393 114558 83067 65008 45824 28751 16072 8922 4747 2436 1233 599 2.19% 8.92% 19.88% 34.64% 42.37% 44.64% 48.28% 50.17% 51.68% 53.74% 52.42% [1] https://github.com/kdlucas/byte-unixbench/tree/master Link: https://lkml.kernel.org/r/20231027033845.90608-11-zhangpeng.00@bytedance.comSigned-off-by:
Peng Zhang <zhangpeng.00@bytedance.com> Suggested-by:
Liam R. Howlett <Liam.Howlett@oracle.com> Reviewed-by:
Andrew Morton <akpm@linux-foundation.org>
-
Peng Zhang authored
When destroying maple tree, preserve its attributes and then turn it into an empty tree. This allows it to be reused without needing to be reinitialized. Link: https://lkml.kernel.org/r/20231027033845.90608-10-zhangpeng.00@bytedance.comSigned-off-by:
-
Peng Zhang authored
Updated check_forking() and bench_forking() to use __mt_dup() to duplicate maple tree. Link: https://lkml.kernel.org/r/20231027033845.90608-9-zhangpeng.00@bytedance.comSigned-off-by:
-
Peng Zhang authored
Skip other tests when BENCH is enabled so that performance can be measured in user space. Link: https://lkml.kernel.org/r/20231027033845.90608-8-zhangpeng.00@bytedance.comSigned-off-by:
-
Peng Zhang authored
Introduce the new interface mtree_dup() in the documentation. Link: https://lkml.kernel.org/r/20231027033845.90608-7-zhangpeng.00@bytedance.comSigned-off-by:
-
Peng Zhang authored
Add test for mtree_dup(). Test by duplicating different maple trees and then comparing the two trees. Includes tests for duplicating full trees and memory allocation failures on different nodes. Link: https://lkml.kernel.org/r/20231027033845.90608-6-zhangpeng.00@bytedance.comSigned-off-by:
-
Peng Zhang authored
When kmem_cache_alloc_bulk() fails to allocate, leave the freed pointers in the array. This enables a more accurate simulation of the kernel's behavior and allows for testing potential double-free scenarios. Link: https://lkml.kernel.org/r/20231027033845.90608-5-zhangpeng.00@bytedance.comSigned-off-by:
-
Peng Zhang authored
Introduce interfaces __mt_dup() and mtree_dup(), which are used to duplicate a maple tree. They duplicate a maple tree in Depth-First Search (DFS) pre-order traversal. It uses memcopy() to copy nodes in the source tree and allocate new child nodes in non-leaf nodes. The new node is exactly the same as the source node except for all the addresses stored in it. It will be faster than traversing all elements in the source tree and inserting them one by one into the new tree. The time complexity of these two functions is O(n). The difference between __mt_dup() and mtree_dup() is that mtree_dup() handles locks internally. Analysis of the average time complexity of this algorithm: For simplicity, let's assume that the maximum branching factor of all non-leaf nodes is 16 (in allocation mode, it is 10), and the tree is a full tree. Under the given conditions, if there is a maple tree with n elements, the number of its leaves is n/16. From bottom to top, the number of nodes in each level is 1/16 of the number of nodes in the level below. So the total number of nodes in the entire tree is given by the sum of n/16 + n/16^2 + n/16^3 + ... + 1. This is a geometric series, and it has log(n) terms with base 16. According to the formula for the sum of a geometric series, the sum of this series can be calculated as (n-1)/15. Each node has only one parent node pointer, which can be considered as an edge. In total, there are (n-1)/15-1 edges. This algorithm consists of two operations: 1. Traversing all nodes in DFS order. 2. For each node, making a copy and performing necessary modifications to create a new node. For the first part, DFS traversal will visit each edge twice. Let T(ascend) represent the cost of taking one step downwards, and T(descend) represent the cost of taking one step upwards. And both of them are constants (although mas_ascend() may not be, as it contains a loop, but here we ignore it and treat it as a constant). So the time spent on the first part can be represented as ((n-1)/15-1) * (T(ascend) + T(descend)). For the second part, each node will be copied, and the cost of copying a node is denoted as T(copy_node). For each non-leaf node, it is necessary to reallocate all child nodes, and the cost of this operation is denoted as T(dup_alloc). The behavior behind memory allocation is complex and not specific to the maple tree operation. Here, we assume that the time required for a single allocation is constant. Since the size of a node is fixed, both of these symbols are also constants. We can calculate that the time spent on the second part is ((n-1)/15) * T(copy_node) + ((n-1)/15 - n/16) * T(dup_alloc). Adding both parts together, the total time spent by the algorithm can be represented as: ((n-1)/15) * (T(ascend) + T(descend) + T(copy_node) + T(dup_alloc)) - n/16 * T(dup_alloc) - (T(ascend) + T(descend)) Let C1 = T(ascend) + T(descend) + T(copy_node) + T(dup_alloc) Let C2 = T(dup_alloc) Let C3 = T(ascend) + T(descend) Finally, the expression can be simplified as: ((16 * C1 - 15 * C2) / (15 * 16)) * n - (C1 / 15 + C3). This is a linear function, so the average time complexity is O(n). Link: https://lkml.kernel.org/r/20231027033845.90608-4-zhangpeng.00@bytedance.comSigned-off-by:
-
Peng Zhang authored
In some cases, nested locks may be needed, so {mtree,mas}_lock_nested is introduced. For example, when duplicating maple tree, we need to hold the locks of two trees, in which case nested locks are needed. At the same time, add the definition of spin_lock_nested() in tools for testing. Link: https://lkml.kernel.org/r/20231027033845.90608-3-zhangpeng.00@bytedance.comSigned-off-by: -
Peng Zhang authored
Patch series "Introduce __mt_dup() to improve the performance of fork()", v7. This series introduces __mt_dup() to improve the performance of fork(). During the duplication process of mmap, all VMAs are traversed and inserted one by one into the new maple tree, causing the maple tree to be rebalanced multiple times. Balancing the maple tree is a costly operation. To duplicate VMAs more efficiently, mtree_dup() and __mt_dup() are introduced for the maple tree. They can efficiently duplicate a maple tree. Here are some algorithmic details about {mtree,__mt}_dup(). We perform a DFS pre-order traversal of all nodes in the source maple tree. During this process, we fully copy the nodes from the source tree to the new tree. This involves memory allocation, and when encountering a new node, if it is a non-leaf node, all its child nodes are allocated at once. This idea was originally from Liam R. Howlett's Maple Tree Work email, and I added some of my own ideas to implement it. Some previous discussions can be found in [1]. For a more detailed analysis of the algorithm, please refer to the logs for patch [3/10] and patch [10/10]. There is a "spawn" in byte-unixbench[2], which can be used to test the performance of fork(). I modified it slightly to make it work with different number of VMAs. Below are the test results. The first row shows the number of VMAs. The second and third rows show the number of fork() calls per ten seconds, corresponding to next-20231006 and the this patchset, respectively. The test results were obtained with CPU binding to avoid scheduler load balancing that could cause unstable results. There are still some fluctuations in the test results, but at least they are better than the original performance. 21 121 221 421 821 1621 3221 6421 12821 25621 51221 112100 76261 54227 34035 20195 11112 6017 3161 1606 802 393 114558 83067 65008 45824 28751 16072 8922 4747 2436 1233 599 2.19% 8.92% 19.88% 34.64% 42.37% 44.64% 48.28% 50.17% 51.68% 53.74% 52.42% Thanks to Liam and Matthew for the review. This patch (of 10): Add two helpers: 1. mt_free_one(), used to free a maple node. 2. mt_attr(), used to obtain the attributes of maple tree. Link: https://lkml.kernel.org/r/20231027033845.90608-1-zhangpeng.00@bytedance.com Link: https://lkml.kernel.org/r/20231027033845.90608-2-zhangpeng.00@bytedance.comSigned-off-by: -
Li Zhijian authored
Demotion will migrate pages across nodes. Previously, only the global demotion statistics were accounted for. Changed them to per-node statistics, making it easier to observe where demotion occurs on each node. This will help to identify which nodes are under pressure. This patch also make pgdemote_* behind CONFIG_NUMA_BALANCING, since demotion is not available for !CONFIG_NUMA_BALANCING With this patch, here is a sample where node0 node1 are DRAM, node3 is PMEM: Global stats: $ grep demote /proc/vmstat pgdemote_kswapd 254288 pgdemote_direct 113497 pgdemote_khugepaged 0 Per-node stats: $ grep demote /sys/devices/system/node/node0/vmstat # demotion source pgdemote_kswapd 68454 pgdemote_direct 83431 pgdemote_khugepaged 0 $ grep demote /sys/devices/system/node/node1/vmstat # demotion source pgdemote_kswapd 185834 pgdemote_direct 30066 pgdemote_khugepaged 0 $ grep demote /sys/devices/system/node/node3/vmstat # demotion target pgdemote_kswapd 0 pgdemote_direct 0 pgdemote_khugepaged 0 Link: https://lkml.kernel.org/r/20231103031450.1456523-1-lizhijian@fujitsu.comSigned-off-by:
Li Zhijian <lizhijian@fujitsu.com> Acked-by:
"Huang, Ying" <ying.huang@intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Signed-off-by:
-
- 07 Dec, 2023 29 commits
-
-
Andrew Morton authored
-
Jiexun Wang authored
I conducted real-time testing and observed that madvise_cold_or_pageout_pte_range() causes significant latency under memory pressure, which can be effectively reduced by adding cond_resched() within the loop. I tested on the LicheePi 4A board using Cylictest for latency testing and Ftrace for latency tracing. The board uses TH1520 processor and has a memory size of 8GB. The kernel version is 6.5.0 with the PREEMPT_RT patch applied. The script I tested is as follows: echo wakeup_rt > /sys/kernel/tracing/current_tracer echo 1 > /sys/kernel/tracing/tracing_on echo 0 > /sys/kernel/tracing/tracing_max_latency stress-ng --vm 8 --vm-bytes 2G & cyclictest --mlockall --smp --priority=99 --distance=0 --duration=30m echo 0 > /sys/kernel/tracing/tracing_on cat /sys/kernel/tracing/trace The tracing results before modification are as follows: # tracer: wakeup_rt # # wakeup_rt latency trace v1.1.5 on 6.5.0-rt6-r1208-00003-g999d221864bf # -------------------------------------------------------------------- # latency: 2552 us, #6/6, CPU#3 | (M:preempt_rt VP:0, KP:0, SP:0 HP:0 #P:4) # ----------------- # | task: cyclictest-196 (uid:0 nice:0 policy:1 rt_prio:99) # ----------------- # # _--------=> CPU# # / _-------=> irqs-off/BH-disabled # | / _------=> need-resched # || / _-----=> need-resched-lazy # ||| / _----=> hardirq/softirq # |||| / _---=> preempt-depth # ||||| / _--=> preempt-lazy-depth # |||||| / _-=> migrate-disable # ||||||| / delay # cmd pid |||||||| time | caller # \ / |||||||| \ | / stress-n-206 3dn.h512 2us : 206:120:R + [003] 196: 0:R cyclictest stress-n-206 3dn.h512 7us : <stack trace> => __ftrace_trace_stack => __trace_stack => probe_wakeup => ttwu_do_activate => try_to_wake_up => wake_up_process => hrtimer_wakeup => __hrtimer_run_queues => hrtimer_interrupt => riscv_timer_interrupt => handle_percpu_devid_irq => generic_handle_domain_irq => riscv_intc_irq => handle_riscv_irq => do_irq stress-n-206 3dn.h512 9us#: 0 stress-n-206 3d...3.. 2544us : __schedule stress-n-206 3d...3.. 2545us : 206:120:R ==> [003] 196: 0:R cyclictest stress-n-206 3d...3.. 2551us : <stack trace> => __ftrace_trace_stack => __trace_stack => probe_wakeup_sched_switch => __schedule => preempt_schedule => migrate_enable => rt_spin_unlock => madvise_cold_or_pageout_pte_range => walk_pgd_range => __walk_page_range => walk_page_range => madvise_pageout => madvise_vma_behavior => do_madvise => sys_madvise => do_trap_ecall_u => ret_from_exception The tracing results after modification are as follows: # tracer: wakeup_rt # # wakeup_rt latency trace v1.1.5 on 6.5.0-rt6-r1208-00004-gca3876fc69a6-dirty # -------------------------------------------------------------------- # latency: 1689 us, #6/6, CPU#0 | (M:preempt_rt VP:0, KP:0, SP:0 HP:0 #P:4) # ----------------- # | task: cyclictest-217 (uid:0 nice:0 policy:1 rt_prio:99) # ----------------- # # _--------=> CPU# # / _-------=> irqs-off/BH-disabled # | / _------=> need-resched # || / _-----=> need-resched-lazy # ||| / _----=> hardirq/softirq # |||| / _---=> preempt-depth # ||||| / _--=> preempt-lazy-depth # |||||| / _-=> migrate-disable # ||||||| / delay # cmd pid |||||||| time | caller # \ / |||||||| \ | / stress-n-232 0dn.h413 1us+: 232:120:R + [000] 217: 0:R cyclictest stress-n-232 0dn.h413 12us : <stack trace> => __ftrace_trace_stack => __trace_stack => probe_wakeup => ttwu_do_activate => try_to_wake_up => wake_up_process => hrtimer_wakeup => __hrtimer_run_queues => hrtimer_interrupt => riscv_timer_interrupt => handle_percpu_devid_irq => generic_handle_domain_irq => riscv_intc_irq => handle_riscv_irq => do_irq stress-n-232 0dn.h413 19us#: 0 stress-n-232 0d...3.. 1671us : __schedule stress-n-232 0d...3.. 1676us+: 232:120:R ==> [000] 217: 0:R cyclictest stress-n-232 0d...3.. 1687us : <stack trace> => __ftrace_trace_stack => __trace_stack => probe_wakeup_sched_switch => __schedule => preempt_schedule => migrate_enable => free_unref_page_list => release_pages => free_pages_and_swap_cache => tlb_batch_pages_flush => tlb_flush_mmu => unmap_page_range => unmap_vmas => unmap_region => do_vmi_align_munmap.constprop.0 => do_vmi_munmap => __vm_munmap => sys_munmap => do_trap_ecall_u => ret_from_exception After the modification, the cause of maximum latency is no longer madvise_cold_or_pageout_pte_range(), so this modification can reduce the latency caused by madvise_cold_or_pageout_pte_range(). Currently the madvise_cold_or_pageout_pte_range() function exhibits significant latency under memory pressure, which can be effectively reduced by adding cond_resched() within the loop. When the batch_count reaches SWAP_CLUSTER_MAX, we reschedule the task to ensure fairness and avoid long lock holding times. Link: https://lkml.kernel.org/r/85363861af65fac66c7a98c251906afc0d9c8098.1695291046.git.wangjiexun@tinylab.orgSigned-off-by:
Jiexun Wang <wangjiexun@tinylab.org> Cc: Zhangjin Wu <falcon@tinylab.org> Signed-off-by:
-
Ryusuke Konishi authored
If nilfs2 reads a disk image with corrupted segment usage metadata, and its segment usage information is marked as an error for the segment at the write location, nilfs_sufile_set_segment_usage() can trigger WARN_ONs during log writing. Segments newly allocated for writing with nilfs_sufile_alloc() will not have this error flag set, but this unexpected situation will occur if the segment indexed by either nilfs->ns_segnum or nilfs->ns_nextnum (active segment) was marked in error. Fix this issue by inserting a sanity check to treat it as a file system corruption. Since error returns are not allowed during the execution phase where nilfs_sufile_set_segment_usage() is used, this inserts the sanity check into nilfs_sufile_mark_dirty() which pre-reads the buffer containing the segment usage record to be updated and sets it up in a dirty state for writing. In addition, nilfs_sufile_set_segment_usage() is also called when canceling log writing and undoing segment usage update, so in order to avoid issuing the same kernel warning in that case, in case of cancellation, avoid checking the error flag in nilfs_sufile_set_segment_usage(). Link: https://lkml.kernel.org/r/20231205085947.4431-1-konishi.ryusuke@gmail.comSigned-off-by:
Ryusuke Konishi <konishi.ryusuke@gmail.com> Reported-by: syzbot+14e9f834f6ddecece094@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=14e9f834f6ddecece094Tested-by:
-
Sidhartha Kumar authored
After commit a08c7193 "mm/filemap: remove hugetlb special casing in filemap.c", hugetlb pages are stored in the page cache in base page sized indexes. This leads to multi index stores in the xarray which is only supporting through CONFIG_XARRAY_MULTI. The other page cache user of multi index stores ,THP, selects XARRAY_MULTI. Have CONFIG_HUGETLB_PAGE follow this behavior as well to avoid the BUG() with a CONFIG_HUGETLB_PAGE && !CONFIG_XARRAY_MULTI config. Link: https://lkml.kernel.org/r/20231204183234.348697-1-sidhartha.kumar@oracle.com Fixes: a08c7193 ("mm/filemap: remove hugetlb special casing in filemap.c") Signed-off-by:
Sidhartha Kumar <sidhartha.kumar@oracle.com> Reported-by:
Al Viro <viro@zeniv.linux.org.uk> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Muchun Song <muchun.song@linux.dev> Signed-off-by:
-
Florian Fainelli authored
After the conversion to bus_to_subsys() and class_to_subsys(), the gdb scripts listing the system buses and classes respectively was broken, fix those by returning the subsys_priv pointer and have the various caller de-reference either the 'bus' or 'class' structure members accordingly. Link: https://lkml.kernel.org/r/20231130043317.174188-1-florian.fainelli@broadcom.com Fixes: 7b884b7f ("driver core: class.c: convert to only use class_to_subsys") Signed-off-by:
Florian Fainelli <florian.fainelli@broadcom.com> Tested-by:
Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jan Kiszka <jan.kiszka@siemens.com> Cc: Kieran Bingham <kbingham@kernel.org> Signed-off-by:
-
Bagas Sanjaya authored
He is currently inactive (last message from him is two years ago [1]). His media tree [2] is also dormant (latest activity is 6 years ago), yet his site is still online [3]. Drop him from MAINTAINERS and add CREDITS entry for him. We thank him for maintaining various DVB drivers. [1]: https://lore.kernel.org/all/660772b3-0597-02db-ed94-c6a9be04e8e8@iki.fi/ [2]: https://git.linuxtv.org/anttip/media_tree.git/ [3]: https://palosaari.fi/linux/ Link: https://lkml.kernel.org/r/20231130083848.5396-1-bagasdotme@gmail.comSigned-off-by:
Bagas Sanjaya <bagasdotme@gmail.com> Acked-by:
Antti Palosaari <crope@iki.fi> Cc: Hans Verkuil <hverkuil-cisco@xs4all.nl> Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com> Cc: Mauro Carvalho Chehab <mchehab@kernel.org> Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by:
-
Su Hui authored
Clang static checker complains that value stored to 'from' is never read. And memcpy_from_folio() only copy the last chunk memory from folio to destination. Use 'to += chunk' to replace 'from += chunk' to fix this typo problem. Link: https://lkml.kernel.org/r/20231130034017.1210429-1-suhui@nfschina.com Fixes: b23d03ef ("highmem: add memcpy_to_folio() and memcpy_from_folio()") Signed-off-by:
Su Hui <suhui@nfschina.com> Reviewed-by:
Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jiaqi Yan <jiaqiyan@google.com> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Peter Collingbourne <pcc@google.com> Cc: Tom Rix <trix@redhat.com> Cc: Tony Luck <tony.luck@intel.com> Cc: <stable@vger.kernel.org> Signed-off-by:
-
Ryusuke Konishi authored
When mounting a filesystem image with a block size larger than the page size, nilfs2 repeatedly outputs long error messages with stack traces to the kernel log, such as the following: getblk(): invalid block size 8192 requested logical block size: 512 ... Call Trace: dump_stack_lvl+0x92/0xd4 dump_stack+0xd/0x10 bdev_getblk+0x33a/0x354 __breadahead+0x11/0x80 nilfs_search_super_root+0xe2/0x704 [nilfs2] load_nilfs+0x72/0x504 [nilfs2] nilfs_mount+0x30f/0x518 [nilfs2] legacy_get_tree+0x1b/0x40 vfs_get_tree+0x18/0xc4 path_mount+0x786/0xa88 __ia32_sys_mount+0x147/0x1a8 __do_fast_syscall_32+0x56/0xc8 do_fast_syscall_32+0x29/0x58 do_SYSENTER_32+0x15/0x18 entry_SYSENTER_32+0x98/0xf1 ... This overloads the system logger. And to make matters worse, it sometimes crashes the kernel with a memory access violation. This is because the return value of the sb_set_blocksize() call, which should be checked for errors, is not checked. The latter issue is due to out-of-buffer memory being accessed based on a large block size that caused sb_set_blocksize() to fail for buffers read with the initial minimum block size that remained unupdated in the super_block structure. Since nilfs2 mkfs tool does not accept block sizes larger than the system page size, this has been overlooked. However, it is possible to create this situation by intentionally modifying the tool or by passing a filesystem image created on a system with a large page size to a system with a smaller page size and mounting it. Fix this issue by inserting the expected error handling for the call to sb_set_blocksize(). Link: https://lkml.kernel.org/r/20231129141547.4726-1-konishi.ryusuke@gmail.comSigned-off-by:
-
Baoquan He authored
Ignat Korchagin complained that a potential config regression was introduced by commit 89cde455 ("kexec: consolidate kexec and crash options into kernel/Kconfig.kexec"). Before the commit, CONFIG_CRASH_DUMP has no dependency on CONFIG_KEXEC. After the commit, CRASH_DUMP selects KEXEC. That enforces system to have CONFIG_KEXEC=y as long as CONFIG_CRASH_DUMP=Y which people may not want. In Ignat's case, he sets CONFIG_CRASH_DUMP=y, CONFIG_KEXEC_FILE=y and CONFIG_KEXEC=n because kexec_load interface could have security issue if kernel/initrd has no chance to be signed and verified. CRASH_DUMP has select of KEXEC because Eric, author of above commit, met a LKP report of build failure when posting patch of earlier version. Please see below link to get detail of the LKP report: https://lore.kernel.org/all/3e8eecd1-a277-2cfb-690e-5de2eb7b988e@oracle.com/T/#u In fact, that LKP report is triggered because arm's <asm/kexec.h> is wrapped in CONFIG_KEXEC ifdeffery scope. That is wrong. CONFIG_KEXEC controls the enabling/disabling of kexec_load interface, but not kexec feature. Removing the wrongly added CONFIG_KEXEC ifdeffery scope in <asm/kexec.h> of arm allows us to drop the select KEXEC for CRASH_DUMP. Meanwhile, change arch/arm/kernel/Makefile to let machine_kexec.o relocate_kernel.o depend on KEXEC_CORE. Link: https://lkml.kernel.org/r/20231128054457.659452-1-bhe@redhat.com Fixes: 89cde455 ("kexec: consolidate kexec and crash options into kernel/Kconfig.kexec") Signed-off-by:
Baoquan He <bhe@redhat.com> Reported-by:
Ignat Korchagin <ignat@cloudflare.com> Tested-by: Ignat Korchagin <ignat@cloudflare.com> [compile-time only] Tested-by:
Alexander Gordeev <agordeev@linux.ibm.com> Reviewed-by:
Eric DeVolder <eric_devolder@yahoo.com> Tested-by:
-
Andy Shevchenko authored
BITS_PER_BYTE is defined in bits.h. Link: https://lkml.kernel.org/r/20231128174404.393393-1-andriy.shevchenko@linux.intel.com Fixes: e8eed5f7 ("units: Add BYTES_PER_*BIT") Signed-off-by:
Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by:
Randy Dunlap <rdunlap@infradead.org> Cc: Damian Muszynski <damian.muszynski@intel.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by:
-
Baoquan He authored
After commit 88a6f899 ("crash: memory and CPU hotplug sysfs attributes"), on x86_64, if only below kernel configs related to kdump are set, compiling error are triggered. ---- CONFIG_CRASH_CORE=y CONFIG_KEXEC_CORE=y CONFIG_CRASH_DUMP=y CONFIG_CRASH_HOTPLUG=y ------ ------------------------------------------------------ drivers/base/cpu.c: In function `crash_hotplug_show': drivers/base/cpu.c:309:40: error: implicit declaration of function `crash_hotplug_cpu_support'; did you mean `crash_hotplug_show'? [-Werror=implicit-function-declaration] 309 | return sysfs_emit(buf, "%d\n", crash_hotplug_cpu_support()); | ^~~~~~~~~~~~~~~~~~~~~~~~~ | crash_hotplug_show cc1: some warnings being treated as errors ------------------------------------------------------ CONFIG_KEXEC is used to enable kexec_load interface, the crash_notes/crash_notes_size/crash_hotplug showing depends on CONFIG_KEXEC is incorrect. It should depend on KEXEC_CORE instead. Fix it now. Link: https://lkml.kernel.org/r/20231128055248.659808-1-bhe@redhat.com Fixes: 88a6f899 ("crash: memory and CPU hotplug sysfs attributes") Signed-off-by:
-
SeongJae Park authored
If a scheme is set to not applied to any monitoring target region for any reasons including the target access pattern, quota, filters, or watermarks, writing 'update_schemes_tried_regions' to 'state' DAMON sysfs file can indefinitely hang. Fix the case by implementing a timeout for the operation. The time limit is two apply intervals of each scheme. Link: https://lkml.kernel.org/r/20231124213840.39157-1-sj@kernel.org Fixes: 4d4e41b6 ("mm/damon/sysfs-schemes: do not update tried regions more than one DAMON snapshot") Signed-off-by:
SeongJae Park <sj@kernel.org> Signed-off-by:
-
Kuan-Ying Lee authored
Since commit 8e1f3851 ("kill task_struct->thread_group") remove the thread_group, we will encounter below issue. (gdb) lx-ps TASK PID COMM 0xffff800086503340 0 swapper/0 Python Exception <class 'gdb.error'>: There is no member named thread_group. Error occurred in Python: There is no member named thread_group. We use signal->thread_head to iterate all threads instead. [Kuan-Ying.Lee@mediatek.com: v2] Link: https://lkml.kernel.org/r/20231129065142.13375-2-Kuan-Ying.Lee@mediatek.com Link: https://lkml.kernel.org/r/20231127070404.4192-2-Kuan-Ying.Lee@mediatek.com Fixes: 8e1f3851 ("kill task_struct->thread_group") Signed-off-by:
Oleg Nesterov <oleg@redhat.com> Tested-by:
-
Peter Xu authored
PTE_MARKER_UFFD_WP is a subconfig for userfaultfd. To make it clear, switch to use menuconfig for userfaultfd. Link: https://lkml.kernel.org/r/20231123224204.1060152-1-peterx@redhat.comSigned-off-by:
Peter Xu <peterx@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Peter Xu <peterx@redhat.com> Signed-off-by:
-
Nico Pache authored
Commit 05f1edac ("selftests/mm: run all tests from run_vmtests.sh") fixed the inconsistency caused by tests being defined as TEST_GEN_PROGS. This issue was leading to tests not being executed via run_vmtests.sh and furthermore some tests running twice due to the kselftests wrapper also executing them. Fix the definition of two tests (soft-dirty and pagemap_ioctl) that are still incorrectly defined. Link: https://lkml.kernel.org/r/20231120222908.28559-1-npache@redhat.comSigned-off-by:
Nico Pache <npache@redhat.com> Reviewed-by:
David Hildenbrand <david@redhat.com> Cc: Joel Savitz <jsavitz@redhat.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by:
-
SeongJae Park authored
Regions split function ('damon_split_region_at()') is called at the beginning of an aggregation interval, and when DAMOS applying the actions and charging quota. Because 'nr_accesses' fields of all regions are reset at the beginning of each aggregation interval, and DAMOS was applying the action at the end of each aggregation interval, there was no need to copy the 'nr_accesses' field to the split-out region. However, commit 42f994b7 ("mm/damon/core: implement scheme-specific apply interval") made DAMOS applies action on its own timing interval. Hence, 'nr_accesses' should also copied to split-out regions, but the commit didn't. Fix it by copying it. Link: https://lkml.kernel.org/r/20231119171529.66863-1-sj@kernel.org Fixes: 42f994b7 ("mm/damon/core: implement scheme-specific apply interval") Signed-off-by: -
Ming Lei authored
group_cpus_evenly() could be part of storage driver's error handler, such as nvme driver, when may happen during CPU hotplug, in which storage queue has to drain its pending IOs because all CPUs associated with the queue are offline and the queue is becoming inactive. And handling IO needs error handler to provide forward progress. Then deadlock is caused: 1) inside CPU hotplug handler, CPU hotplug lock is held, and blk-mq's handler is waiting for inflight IO 2) error handler is waiting for CPU hotplug lock 3) inflight IO can't be completed in blk-mq's CPU hotplug handler because error handling can't provide forward progress. Solve the deadlock by not holding CPU hotplug lock in group_cpus_evenly(), in which two stage spreads are taken: 1) the 1st stage is over all present CPUs; 2) the end stage is over all other CPUs. Turns out the two stage spread just needs consistent 'cpu_present_mask', and remove the CPU hotplug lock by storing it into one local cache. This way doesn't change correctness, because all CPUs are still covered. Link: https://lkml.kernel.org/r/20231120083559.285174-1-ming.lei@redhat.comSigned-off-by:
Ming Lei <ming.lei@redhat.com> Reported-by:
Yi Zhang <yi.zhang@redhat.com> Reported-by:
Guangwu Zhang <guazhang@redhat.com> Tested-by:
Chengming Zhou <zhouchengming@bytedance.com> Reviewed-by:
Jens Axboe <axboe@kernel.dk> Cc: Keith Busch <kbusch@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by:
-
Heiko Carstens authored
All addresses printed by checkstack have an extra incorrect 0 appended at the end. This was introduced with commit 677f1410 ("scripts/checkstack.pl: don't display $dre as different entity"): since then the address is taken from the line which contains the function name, instead of the line which contains stack consumption. E.g. on s390: 0000000000100a30 <do_one_initcall>: ... 100a44: e3 f0 ff 70 ff 71 lay %r15,-144(%r15) So the used regex which matches spaces and hexadecimal numbers to extract an address now matches a different substring. Subsequently replacing spaces with 0 appends a zero at the and, instead of replacing leading spaces. Fix this by using the proper regex, and simplify the code a bit. Link: https://lkml.kernel.org/r/20231120183719.2188479-2-hca@linux.ibm.com Fixes: 677f1410 ("scripts/checkstack.pl: don't display $dre as different entity") Signed-off-by:
Heiko Carstens <hca@linux.ibm.com> Cc: Maninder Singh <maninder1.s@samsung.com> Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: Vaneet Narang <v.narang@samsung.com> Cc: <stable@vger.kernel.org> Signed-off-by:
-
Sumanth Korikkar authored
In add_memory_resource(), creation of memory block devices occurs after successful call to arch_add_memory(). However, creation of memory block devices could fail. In that case, arch_remove_memory() is called to perform necessary cleanup. Currently with or without altmap support, arch_remove_memory() is always passed with altmap set to NULL during error handling. This leads to freeing of struct pages using free_pages(), eventhough the allocation might have been performed with altmap support via altmap_alloc_block_buf(). Fix the error handling by passing altmap in arch_remove_memory(). This ensures the following: * When altmap is disabled, deallocation of the struct pages array occurs via free_pages(). * When altmap is enabled, deallocation occurs via vmem_altmap_free(). Link: https://lkml.kernel.org/r/20231120145354.308999-3-sumanthk@linux.ibm.com Fixes: a08a2ae3 ("mm,memory_hotplug: allocate memmap from the added memory range") Signed-off-by:
Sumanth Korikkar <sumanthk@linux.ibm.com> Reviewed-by:
Gerald Schaefer <gerald.schaefer@linux.ibm.com> Acked-by:
-
Sumanth Korikkar authored
From Documentation/core-api/memory-hotplug.rst: When adding/removing/onlining/offlining memory or adding/removing heterogeneous/device memory, we should always hold the mem_hotplug_lock in write mode to serialise memory hotplug (e.g. access to global/zone variables). mhp_(de)init_memmap_on_memory() functions can change zone stats and struct page content, but they are currently called w/o the mem_hotplug_lock. When memory block is being offlined and when kmemleak goes through each populated zone, the following theoretical race conditions could occur: CPU 0: | CPU 1: memory_offline() | -> offline_pages() | -> mem_hotplug_begin() | ... | -> mem_hotplug_done() | | kmemleak_scan() | -> get_online_mems() | ... -> mhp_deinit_memmap_on_memory() | [not protected by mem_hotplug_begin/done()]| Marks memory section as offline, | Retrieves zone_start_pfn poisons vmemmap struct pages and updates | and struct page members. the zone related data | | ... | -> put_online_mems() Fix this by ensuring mem_hotplug_lock is taken before performing mhp_init_memmap_on_memory(). Also ensure that mhp_deinit_memmap_on_memory() holds the lock. online/offline_pages() are currently only called from memory_block_online/offline(), so it is safe to move the locking there. Link: https://lkml.kernel.org/r/20231120145354.308999-2-sumanthk@linux.ibm.com Fixes: a08a2ae3 ("mm,memory_hotplug: allocate memmap from the added memory range") Signed-off-by:
-
Chester Lin authored
My company email address is going to be disabled so let's create a mapping that links to my private/community email just in case people might still try to reach me via the old one. Link: https://lkml.kernel.org/r/20231117022807.29461-1-clin@suse.comSigned-off-by:
Chester Lin <clin@suse.com> Cc: Chester Lin <chester62515@gmail.com> Cc: Bjorn Andersson <quic_bjorande@quicinc.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Heiko Stuebner <heiko@sntech.de> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Konrad Dybcio <konrad.dybcio@linaro.org> Cc: Oleksij Rempel <o.rempel@pengutronix.de> Cc: Stephen Hemminger <stephen@networkplumber.org> Cc: Conor Dooley <conor.dooley@microchip.com> Cc: Matthias Brugger <mbrugger@suse.com> Signed-off-by:
-
Hugh Dickins authored
syzbot reports oops in lockdep's __lock_acquire(), called from __pte_offset_map_lock() called from filemap_map_pages(); or when I run the repro, the oops comes in pmd_install(), called from filemap_map_pmd() called from filemap_map_pages(), just before the __pte_offset_map_lock(). The problem is that filemap_map_pmd() has been assuming that when it finds pmd_none(), a page table has already been prepared in prealloc_pte; and indeed do_fault_around() has been careful to preallocate one there, when it finds pmd_none(): but what if *pmd became none in between? My 6.6 mods in mm/khugepaged.c, avoiding mmap_lock for write, have made it easy for *pmd to be cleared while servicing a page fault; but even before those, a huge *pmd might be zapped while a fault is serviced. The difference in symptomatic stack traces comes from the "memory model" in use: pmd_install() uses pmd_populate() uses page_to_pfn(): in some models that is strict, and will oops on the NULL prealloc_pte; in other models, it will construct a bogus value to be populated into *pmd, then __pte_offset_map_lock() oops when trying to access split ptlock pointer (or some other symptom in normal case of ptlock embedded not pointer). Link: https://lore.kernel.org/linux-mm/20231115065506.19780-1-jose.pekkarinen@foxhound.fi/ Link: https://lkml.kernel.org/r/6ed0c50c-78ef-0719-b3c5-60c0c010431c@google.com Fixes: f9ce0be7 ("mm: Cleanup faultaround and finish_fault() codepaths") Signed-off-by:
Hugh Dickins <hughd@google.com> Reported-and-tested-by: syzbot+89edd67979b52675ddec@syzkaller.appspotmail.com Closes: https://lore.kernel.org/linux-mm/0000000000005e44550608a0806c@google.com/Reviewed-by:
-
Lizhi Xu authored
When the length passed in is 0, the pagemap_scan_test_walk() caller should bail. This error causes at least a WARN_ON(). Link: https://lkml.kernel.org/r/20231116031352.40853-1-lizhi.xu@windriver.com Reported-by: syzbot+32d3767580a1ea339a81@syzkaller.appspotmail.com Closes: https://lkml.kernel.org/r/0000000000000526f2060a30a085@google.comSigned-off-by:
Lizhi Xu <lizhi.xu@windriver.com> Reviewed-by:
Phillip Lougher <phillip@squashfs.org.uk> Signed-off-by:
-
Peter Xu authored
__FILE__ is not guaranteed to exist in current dir. Replace that with argv[0] for memory map test. Link: https://lkml.kernel.org/r/20231116201547.536857-4-peterx@redhat.com Fixes: 46fd75d4 ("selftests: mm: add pagemap ioctl tests") Signed-off-by:
-
Peter Xu authored
The new pagemap ioctl contains a fast path for wr-protections without looking into category masks. It forgets to check PM_SCAN_WP_MATCHING before applying the wr-protections. It can cause, e.g., pte markers installed on archs that do not even support uffd wr-protect. WARNING: CPU: 0 PID: 5059 at mm/memory.c:1520 zap_pte_range mm/memory.c:1520 [inline] Link: https://lkml.kernel.org/r/20231116201547.536857-3-peterx@redhat.com Fixes: 12f6b01a ("fs/proc/task_mmu: add fast paths to get/clear PAGE_IS_WRITTEN flag") Signed-off-by:
Andrei Vagin <avagin@gmail.com> Cc: Muhammad Usama Anjum <usama.anjum@collabora.com> Signed-off-by:
-
Peter Xu authored
Patch series "mm/pagemap: A few fixes to the recent PAGEMAP_SCAN". This series should fix two known reports from syzbot on the new PAGEMAP_SCAN ioctl(): https://lore.kernel.org/all/000000000000b0e576060a30ee3b@google.com/ https://lore.kernel.org/all/000000000000773fa7060a31e2cc@google.com/ The 3rd patch is something I found when testing these patches. This patch (of 3): The new ioctl(PAGEMAP_SCAN) relies on vma wr-protect capability provided by userfault, however in the vma test it didn't explicitly require the vma to have wr-protect function enabled, even if PM_SCAN_WP_MATCHING flag is set. It means the pagemap code can now apply uffd-wp bit to a page in the vma even if not registered to userfaultfd at all. Then in whatever way as long as the pte got written and page fault resolved, we'll apply the write bit even if uffd-wp bit is set. We'll see a pte that has both UFFD_WP and WRITE bit set. Anything later that looks up the pte for uffd-wp bit will trigger the warning: WARNING: CPU: 1 PID: 5071 at arch/x86/include/asm/pgtable.h:403 pte_uffd_wp arch/x86/include/asm/pgtable.h:403 [inline] Fix it by doing proper check over the vma attributes when PM_SCAN_WP_MATCHING is specified. Link: https://lkml.kernel.org/r/20231116201547.536857-1-peterx@redhat.com Link: https://lkml.kernel.org/r/20231116201547.536857-2-peterx@redhat.com Fixes: 52526ca7 ("fs/proc/task_mmu: implement IOCTL to get and optionally clear info about PTEs") Signed-off-by:
Muhammad Usama Anjum <usama.anjum@collabora.com> Signed-off-by:
-
Roman Gushchin authored
Erhard reported that the 6.7-rc1 kernel panics on boot if being built with clang-16. The problem was not reproducible with gcc. [ 5.975049] general protection fault, probably for non-canonical address 0xf555515555555557: 0000 [#1] SMP KASAN PTI [ 5.976422] KASAN: maybe wild-memory-access in range [0xaaaaaaaaaaaaaab8-0xaaaaaaaaaaaaaabf] [ 5.977475] CPU: 3 PID: 1 Comm: systemd Not tainted 6.7.0-rc1-Zen3 #77 [ 5.977860] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 [ 5.977860] RIP: 0010:obj_cgroup_charge_pages+0x27/0x2d5 [ 5.977860] Code: 90 90 90 55 41 57 41 56 41 55 41 54 53 89 d5 41 89 f6 49 89 ff 48 b8 00 00 00 00 00 fc ff df 49 83 c7 10 4d3 [ 5.977860] RSP: 0018:ffffc9000001fb18 EFLAGS: 00010a02 [ 5.977860] RAX: dffffc0000000000 RBX: aaaaaaaaaaaaaaaa RCX: ffff8883eb9a8b08 [ 5.977860] RDX: 0000000000000005 RSI: 0000000000400cc0 RDI: aaaaaaaaaaaaaaaa [ 5.977860] RBP: 0000000000000005 R08: 3333333333333333 R09: 0000000000000000 [ 5.977860] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8883eb9a8b18 [ 5.977860] R13: 1555555555555557 R14: 0000000000400cc0 R15: aaaaaaaaaaaaaaba [ 5.977860] FS: 00007f2976438b40(0000) GS:ffff8883eb980000(0000) knlGS:0000000000000000 [ 5.977860] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 5.977860] CR2: 00007f29769e0060 CR3: 0000000107222003 CR4: 0000000000370eb0 [ 5.977860] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 5.977860] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 5.977860] Call Trace: [ 5.977860] <TASK> [ 5.977860] ? __die_body+0x16/0x75 [ 5.977860] ? die_addr+0x4a/0x70 [ 5.977860] ? exc_general_protection+0x1c9/0x2d0 [ 5.977860] ? cgroup_mkdir+0x455/0x9fb [ 5.977860] ? __x64_sys_mkdir+0x69/0x80 [ 5.977860] ? asm_exc_general_protection+0x26/0x30 [ 5.977860] ? obj_cgroup_charge_pages+0x27/0x2d5 [ 5.977860] obj_cgroup_charge+0x114/0x1ab [ 5.977860] pcpu_alloc+0x1a6/0xa65 [ 5.977860] ? mem_cgroup_css_alloc+0x1eb/0x1140 [ 5.977860] ? cgroup_apply_control_enable+0x26b/0x7c0 [ 5.977860] mem_cgroup_css_alloc+0x23f/0x1140 [ 5.977860] cgroup_apply_control_enable+0x26b/0x7c0 [ 5.977860] ? cgroup_kn_set_ugid+0x2d/0x1a0 [ 5.977860] cgroup_mkdir+0x455/0x9fb [ 5.977860] ? __cfi_cgroup_mkdir+0x10/0x10 [ 5.977860] kernfs_iop_mkdir+0x130/0x170 [ 5.977860] vfs_mkdir+0x405/0x530 [ 5.977860] do_mkdirat+0x188/0x1f0 [ 5.977860] __x64_sys_mkdir+0x69/0x80 [ 5.977860] do_syscall_64+0x7d/0x100 [ 5.977860] ? do_syscall_64+0x89/0x100 [ 5.977860] ? do_syscall_64+0x89/0x100 [ 5.977860] ? do_syscall_64+0x89/0x100 [ 5.977860] ? do_syscall_64+0x89/0x100 [ 5.977860] entry_SYSCALL_64_after_hwframe+0x4b/0x53 [ 5.977860] RIP: 0033:0x7f297671defb [ 5.977860] Code: 8b 05 39 7f 0d 00 bb ff ff ff ff 64 c7 00 16 00 00 00 e9 61 ff ff ff e8 23 0c 02 00 0f 1f 00 f3 0f 1e fa b88 [ 5.977860] RSP: 002b:00007ffee6242bb8 EFLAGS: 00000246 ORIG_RAX: 0000000000000053 [ 5.977860] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f297671defb [ 5.977860] RDX: 0000000000000000 RSI: 00000000000001ed RDI: 000055c6b449f0e0 [ 5.977860] RBP: 00007ffee6242bf0 R08: 000000000000000e R09: 0000000000000000 [ 5.977860] R10: 0000000000000000 R11: 0000000000000246 R12: 000055c6b445db80 [ 5.977860] R13: 00000000000003a0 R14: 00007f2976a68651 R15: 00000000000003a0 [ 5.977860] </TASK> [ 5.977860] Modules linked in: [ 6.014095] ---[ end trace 0000000000000000 ]--- [ 6.014701] RIP: 0010:obj_cgroup_charge_pages+0x27/0x2d5 [ 6.015348] Code: 90 90 90 55 41 57 41 56 41 55 41 54 53 89 d5 41 89 f6 49 89 ff 48 b8 00 00 00 00 00 fc ff df 49 83 c7 10 4d3 [ 6.017575] RSP: 0018:ffffc9000001fb18 EFLAGS: 00010a02 [ 6.018255] RAX: dffffc0000000000 RBX: aaaaaaaaaaaaaaaa RCX: ffff8883eb9a8b08 [ 6.019120] RDX: 0000000000000005 RSI: 0000000000400cc0 RDI: aaaaaaaaaaaaaaaa [ 6.019983] RBP: 0000000000000005 R08: 3333333333333333 R09: 0000000000000000 [ 6.020849] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8883eb9a8b18 [ 6.021747] R13: 1555555555555557 R14: 0000000000400cc0 R15: aaaaaaaaaaaaaaba [ 6.022609] FS: 00007f2976438b40(0000) GS:ffff8883eb980000(0000) knlGS:0000000000000000 [ 6.023593] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 6.024296] CR2: 00007f29769e0060 CR3: 0000000107222003 CR4: 0000000000370eb0 [ 6.025279] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 6.026139] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 6.027000] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b Actually the problem is caused by uninitialized local variable in current_obj_cgroup(). If the root memory cgroup is set as an active memory cgroup for a charging scope (as in the trace, where systemd tries to create the first non-root cgroup, so the parent cgroup is the root cgroup), the "for" loop is skipped and uninitialized objcg is returned, causing a panic down the accounting stack. The fix is trivial: initialize the objcg variable to NULL unconditionally before the "for" loop. [vbabka@suse.cz: remove redundant assignment] Link: https://lkml.kernel.org/r/4bd106d5-c3e3-6731-9a74-cff81e2392de@suse.cz Link: https://lkml.kernel.org/r/20231116025109.3775055-1-roman.gushchin@linux.dev Fixes: e86828e5 ("mm: kmem: scoped objcg protection") Signed-off-by:
Roman Gushchin (Cruise) <roman.gushchin@linux.dev> Signed-off-by:
Vlastimil Babka <vbabka@suse.cz> Reported-by:
Erhard Furtner <erhard_f@mailbox.org> Closes: https://github.com/ClangBuiltLinux/linux/issues/1959Tested-by:
Shakeel Butt <shakeelb@google.com> Cc: David Rientjes <rientjes@google.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Signed-off-by:
-
Liu Shixin authored
set_track_prepare() will call __alloc_pages() which attempts to acquire zone->lock(spinlocks), so move it outside object->lock(raw_spinlocks) because it's not right to acquire spinlocks while holding raw_spinlocks in RT mode. Link: https://lkml.kernel.org/r/20231115082138.2649870-3-liushixin2@huawei.comSigned-off-by:
Liu Shixin <liushixin2@huawei.com> Acked-by:
Catalin Marinas <catalin.marinas@arm.com> Cc: Geert Uytterhoeven <geert+renesas@glider.be> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Patrick Wang <patrick.wang.shcn@gmail.com> Signed-off-by:
-
Liu Shixin authored
Patch series "Fix invalid wait context of set_track_prepare()". Geert reported an invalid wait context[1] which is resulted by moving set_track_prepare() inside kmemleak_lock. This is not allowed because in RT mode, the spinlocks can be preempted but raw_spinlocks can not, so it is not allowd to acquire spinlocks while holding raw_spinlocks. The second patch fix same problem in kmemleak_update_trace(). This patch (of 2): Move the initialisation of object back to__alloc_object() because set_track_prepare() attempt to acquire zone->lock(spinlocks) while __link_object is holding kmemleak_lock(raw_spinlocks). This is not right for RT mode. This reverts commit 245245c2 ("mm/kmemleak: move the initialisation of object to __link_object"). Link: https://lkml.kernel.org/r/20231115082138.2649870-1-liushixin2@huawei.com Link: https://lkml.kernel.org/r/20231115082138.2649870-2-liushixin2@huawei.com Fixes: 245245c2 ("mm/kmemleak: move the initialisation of object to __link_object") Signed-off-by:
Geert Uytterhoeven <geert+renesas@glider.be> Closes: https://lore.kernel.org/linux-mm/CAMuHMdWj0UzwNaxUvcocTfh481qRJpOWwXxsJCTJfu1oCqvgdA@mail.gmail.com/ [1] Acked-by:
-
