7f439bc2d7
We observed a large(order-3) allocation in evdev_open() and it may cause an OOM kernel panic in kzalloc(), before we getting to the vzalloc() fallback. Fix it by converting kzalloc()/vzalloc() to kvzalloc() to avoid the OOM killer logic as we have a vmalloc fallback. InputReader invoked oom-killer: gfp_mask=0x240c2c0 (GFP_KERNEL|__GFP_NOWARN|__GFP_COMP|__GFP_ZERO), nodemask=0, order=3, oom_score_adj=-900 ... (dump_backtrace) from (show_stack+0x18/0x1c) (show_stack) from (dump_stack+0x94/0xa8) (dump_stack) from (dump_header+0x7c/0xe4) (dump_header) from (out_of_memory+0x334/0x348) (out_of_memory) from (__alloc_pages_nodemask+0xe9c/0xeb8) (__alloc_pages_nodemask) from (kmalloc_order_trace+0x34/0x128) (kmalloc_order_trace) from (__kmalloc+0x258/0x36c) (__kmalloc) from (evdev_open+0x5c/0x17c) (evdev_open) from (chrdev_open+0x100/0x204) (chrdev_open) from (do_dentry_open+0x21c/0x354) (do_dentry_open) from (vfs_open+0x58/0x84) (vfs_open) from (path_openat+0x640/0xc98) (path_openat) from (do_filp_open+0x78/0x11c) (do_filp_open) from (do_sys_open+0x130/0x244) (do_sys_open) from (SyS_openat+0x14/0x18) (SyS_openat) from (__sys_trace_return+0x0/0x10) ... Normal: 12488*4kB (UMEH) 6984*8kB (UMEH) 2101*16kB (UMEH) 0*32kB 0*64kB 0*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 139440kB HighMem: 206*4kB (H) 131*8kB (H) 42*16kB (H) 2*32kB (H) 0*64kB 0*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 2608kB ... Kernel panic - not syncing: Out of memory and no killable processes... Signed-off-by: Miles Chen <miles.chen@mediatek.com> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
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 Restructured Text 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.