Revision 9c29bcd189f4ab1644b7125713602532d0aefdb7 authored by Eric Dumazet on 21 September 2018, 22:27:48 UTC, committed by David S. Miller on 24 September 2018, 04:55:25 UTC
As diagnosed by Song Liu, ndo_poll_controller() can be very dangerous on loaded hosts, since the cpu calling ndo_poll_controller() might steal all NAPI contexts (for all RX/TX queues of the NIC). This capture can last for unlimited amount of time, since one cpu is generally not able to drain all the queues under load. mlx5 uses NAPI for TX completions, so we better let core networking stack call the napi->poll() to avoid the capture. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Saeed Mahameed <saeedm@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
1 parent a24b66c
thread-stack.h
/*
* thread-stack.h: Synthesize a thread's stack using call / return events
* Copyright (c) 2014, Intel Corporation.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
*/
#ifndef __PERF_THREAD_STACK_H
#define __PERF_THREAD_STACK_H
#include <sys/types.h>
#include <linux/types.h>
struct thread;
struct comm;
struct ip_callchain;
struct symbol;
struct dso;
struct comm;
struct perf_sample;
struct addr_location;
struct call_path;
/*
* Call/Return flags.
*
* CALL_RETURN_NO_CALL: 'return' but no matching 'call'
* CALL_RETURN_NO_RETURN: 'call' but no matching 'return'
*/
enum {
CALL_RETURN_NO_CALL = 1 << 0,
CALL_RETURN_NO_RETURN = 1 << 1,
};
/**
* struct call_return - paired call/return information.
* @thread: thread in which call/return occurred
* @comm: comm in which call/return occurred
* @cp: call path
* @call_time: timestamp of call (if known)
* @return_time: timestamp of return (if known)
* @branch_count: number of branches seen between call and return
* @call_ref: external reference to 'call' sample (e.g. db_id)
* @return_ref: external reference to 'return' sample (e.g. db_id)
* @db_id: id used for db-export
* @flags: Call/Return flags
*/
struct call_return {
struct thread *thread;
struct comm *comm;
struct call_path *cp;
u64 call_time;
u64 return_time;
u64 branch_count;
u64 call_ref;
u64 return_ref;
u64 db_id;
u32 flags;
};
/**
* struct call_return_processor - provides a call-back to consume call-return
* information.
* @cpr: call path root
* @process: call-back that accepts call/return information
* @data: anonymous data for call-back
*/
struct call_return_processor {
struct call_path_root *cpr;
int (*process)(struct call_return *cr, void *data);
void *data;
};
int thread_stack__event(struct thread *thread, u32 flags, u64 from_ip,
u64 to_ip, u16 insn_len, u64 trace_nr);
void thread_stack__set_trace_nr(struct thread *thread, u64 trace_nr);
void thread_stack__sample(struct thread *thread, struct ip_callchain *chain,
size_t sz, u64 ip);
int thread_stack__flush(struct thread *thread);
void thread_stack__free(struct thread *thread);
size_t thread_stack__depth(struct thread *thread);
struct call_return_processor *
call_return_processor__new(int (*process)(struct call_return *cr, void *data),
void *data);
void call_return_processor__free(struct call_return_processor *crp);
int thread_stack__process(struct thread *thread, struct comm *comm,
struct perf_sample *sample,
struct addr_location *from_al,
struct addr_location *to_al, u64 ref,
struct call_return_processor *crp);
#endif
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