mirror of
https://github.com/torvalds/linux.git
synced 2025-12-07 20:06:24 +00:00
d056bc45b6
When a process exits with numerous large, pinned memory regions consisting of 4KB pages, the cleanup of the memory region through __ib_umem_release() may cause soft lockups. This is because unpin_user_page_range_dirty_lock() is called in a tight loop for unpin and releasing page without yielding the CPU. watchdog: BUG: soft lockup - CPU#44 stuck for 26s! [python3:73464] Kernel panic - not syncing: softlockup: hung tasks CPU: 44 PID: 73464 Comm: python3 Tainted: G OEL asm_sysvec_apic_timer_interrupt+0x1b/0x20 RIP: 0010:free_unref_page+0xff/0x190 ? free_unref_page+0xe3/0x190 __put_page+0x77/0xe0 put_compound_head+0xed/0x100 unpin_user_page_range_dirty_lock+0xb2/0x180 __ib_umem_release+0x57/0xb0 [ib_core] ib_umem_release+0x3f/0xd0 [ib_core] mlx5_ib_dereg_mr+0x2e9/0x440 [mlx5_ib] ib_dereg_mr_user+0x43/0xb0 [ib_core] uverbs_free_mr+0x15/0x20 [ib_uverbs] destroy_hw_idr_uobject+0x21/0x60 [ib_uverbs] uverbs_destroy_uobject+0x38/0x1b0 [ib_uverbs] __uverbs_cleanup_ufile+0xd1/0x150 [ib_uverbs] uverbs_destroy_ufile_hw+0x3f/0x100 [ib_uverbs] ib_uverbs_close+0x1f/0xb0 [ib_uverbs] __fput+0x9c/0x280 ____fput+0xe/0x20 task_work_run+0x6a/0xb0 do_exit+0x217/0x3c0 do_group_exit+0x3b/0xb0 get_signal+0x150/0x900 arch_do_signal_or_restart+0xde/0x100 exit_to_user_mode_loop+0xc4/0x160 exit_to_user_mode_prepare+0xa0/0xb0 syscall_exit_to_user_mode+0x27/0x50 do_syscall_64+0x63/0xb0 Fix soft lockup issues by incorporating cond_resched() calls within __ib_umem_release(), and this SG entries are typically grouped in 2MB chunks on x86_64, adding cond_resched() should has minimal performance impact. Signed-off-by: Li RongQing <lirongqing@baidu.com> Link: https://patch.msgid.link/20251113095317.2628-1-lirongqing@baidu.com Acked-by: Junxian Huang <huangjunxian6@hisilicon.com> Signed-off-by: Leon Romanovsky <leon@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.