Messages in this thread | ![/](/images/icornerl.gif) | | Date | Thu, 30 Jul 2020 09:58:42 -0400 | From | Steven Rostedt <> | Subject | Re: [PATCH] trace : use kvmalloc instead of kmalloc |
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On Thu, 30 Jul 2020 19:04:12 +0800 Zhaoyang Huang <huangzhaoyang@gmail.com> wrote:
> High order memory stuff within trace could introduce OOM, use kvmalloc instead. > > Please find the bellowing for the call stack we run across in an android system. The scenario happens when traced_probes is woken up to get a large quantity of trace even if free memory is even higher than watermark_low.
Please limit your column width in the description of patches to 76 characters.
> > traced_probes invoked oom-killer: gfp_mask=0x140c0c0(GFP_KERNEL|__GFP_COMP|__GFP_ZERO), nodemask=(null), order=2, oom_score_adj=-1 >
What does this traced_probes thing do?
> traced_probes cpuset=system-background mems_allowed=0 > CPU: 3 PID: 588 Comm: traced_probes Tainted: G W O 4.14.181 #1 > Hardware name: Generic DT based system > (unwind_backtrace) from [<c010d824>] (show_stack+0x20/0x24) > (show_stack) from [<c0b2e174>] (dump_stack+0xa8/0xec) > (dump_stack) from [<c027d584>] (dump_header+0x9c/0x220) > (dump_header) from [<c027cfe4>] (oom_kill_process+0xc0/0x5c4) > (oom_kill_process) from [<c027cb94>] (out_of_memory+0x220/0x310) > (out_of_memory) from [<c02816bc>] (__alloc_pages_nodemask+0xff8/0x13a4) > (__alloc_pages_nodemask) from [<c02a6a1c>] (kmalloc_order+0x30/0x48) > (kmalloc_order) from [<c02a6a64>] (kmalloc_order_trace+0x30/0x118) > (kmalloc_order_trace) from [<c0223d7c>] (tracing_buffers_open+0x50/0xfc) > (tracing_buffers_open) from [<c02e6f58>] (do_dentry_open+0x278/0x34c) > (do_dentry_open) from [<c02e70d0>] (vfs_open+0x50/0x70) > (vfs_open) from [<c02f7c24>] (path_openat+0x5fc/0x169c) > (path_openat) from [<c02f75c4>] (do_filp_open+0x94/0xf8) > (do_filp_open) from [<c02e7650>] (do_sys_open+0x168/0x26c) > (do_sys_open) from [<c02e77bc>] (SyS_openat+0x34/0x38) > (SyS_openat) from [<c0108bc0>] (ret_fast_syscall+0x0/0x28) > > Signed-off-by: Zhaoyang Huang <zhaoyang.huang@unisoc.com> > --- > changes since v1: change kfree to kvfree > --- > kernel/trace/trace.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c > index ca1ee65..8d70c79 100644 > --- a/kernel/trace/trace.c > +++ b/kernel/trace/trace.c > @@ -6891,7 +6891,7 @@ static int tracing_buffers_open(struct inode *inode, struct file *filp) > if (trace_array_get(tr) < 0) > return -ENODEV; > > - info = kzalloc(sizeof(*info), GFP_KERNEL); > + info = kvmalloc(sizeof(*info), GFP_KERNEL);
The above is a bug. It converts kzalloc() to kvmalloc() instead of kvzalloc().
-- Steve
> if (!info) { > trace_array_put(tr); > return -ENOMEM; > @@ -7017,7 +7017,7 @@ static int tracing_buffers_release(struct inode *inode, struct file *file) > if (info->spare) > ring_buffer_free_read_page(iter->trace_buffer->buffer, > info->spare_cpu, info->spare); > - kfree(info); > + kvfree(info); > > mutex_unlock(&trace_types_lock); >
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