Re: [PATCH printk v1 11/18] printk: nobkl: Introduce printer threads

From: kernel test robot
Date: Thu Mar 02 2023 - 20:23:51 EST


Hi John,

I love your patch! Yet something to improve:

[auto build test ERROR on 10d639febe5629687dac17c4a7500a96537ce11a]

url: https://github.com/intel-lab-lkp/linux/commits/John-Ogness/kdb-do-not-assume-write-callback-available/20230303-040039
base: 10d639febe5629687dac17c4a7500a96537ce11a
patch link: https://lore.kernel.org/r/20230302195618.156940-12-john.ogness%40linutronix.de
patch subject: [PATCH printk v1 11/18] printk: nobkl: Introduce printer threads
config: nios2-buildonly-randconfig-r004-20230302 (https://download.01.org/0day-ci/archive/20230303/202303030957.Hkt9zcFz-lkp@xxxxxxxxx/config)
compiler: nios2-linux-gcc (GCC) 12.1.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/intel-lab-lkp/linux/commit/72ef8a364036e7e813e7f7dfa8d37a4466d1ca8a
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review John-Ogness/kdb-do-not-assume-write-callback-available/20230303-040039
git checkout 72ef8a364036e7e813e7f7dfa8d37a4466d1ca8a
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=nios2 olddefconfig
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=nios2 SHELL=/bin/bash kernel/printk/

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@xxxxxxxxx>
| Link: https://lore.kernel.org/oe-kbuild-all/202303030957.Hkt9zcFz-lkp@xxxxxxxxx/

All errors (new ones prefixed by >>):

kernel/printk/printk.c:2802:6: warning: no previous prototype for 'printk_get_next_message' [-Wmissing-prototypes]
2802 | bool printk_get_next_message(struct printk_message *pmsg, u64 seq,
| ^~~~~~~~~~~~~~~~~~~~~~~
kernel/printk/printk.c: In function 'console_flush_all':
>> kernel/printk/printk.c:2979:30: error: implicit declaration of function 'console_is_usable'; did you mean 'console_exit_unsafe'? [-Werror=implicit-function-declaration]
2979 | if (!console_is_usable(con, flags))
| ^~~~~~~~~~~~~~~~~
| console_exit_unsafe
cc1: some warnings being treated as errors


vim +2979 kernel/printk/printk.c

a699449bb13b70b kernel/printk/printk.c John Ogness 2022-04-21 2933
a699449bb13b70b kernel/printk/printk.c John Ogness 2022-04-21 2934 /*
a699449bb13b70b kernel/printk/printk.c John Ogness 2022-04-21 2935 * Print out all remaining records to all consoles.
a699449bb13b70b kernel/printk/printk.c John Ogness 2022-04-21 2936 *
a699449bb13b70b kernel/printk/printk.c John Ogness 2022-04-21 2937 * @do_cond_resched is set by the caller. It can be true only in schedulable
a699449bb13b70b kernel/printk/printk.c John Ogness 2022-04-21 2938 * context.
a699449bb13b70b kernel/printk/printk.c John Ogness 2022-04-21 2939 *
a699449bb13b70b kernel/printk/printk.c John Ogness 2022-04-21 2940 * @next_seq is set to the sequence number after the last available record.
a699449bb13b70b kernel/printk/printk.c John Ogness 2022-04-21 2941 * The value is valid only when this function returns true. It means that all
a699449bb13b70b kernel/printk/printk.c John Ogness 2022-04-21 2942 * usable consoles are completely flushed.
a699449bb13b70b kernel/printk/printk.c John Ogness 2022-04-21 2943 *
a699449bb13b70b kernel/printk/printk.c John Ogness 2022-04-21 2944 * @handover will be set to true if a printk waiter has taken over the
a699449bb13b70b kernel/printk/printk.c John Ogness 2022-04-21 2945 * console_lock, in which case the caller is no longer holding the
a699449bb13b70b kernel/printk/printk.c John Ogness 2022-04-21 2946 * console_lock. Otherwise it is set to false.
a699449bb13b70b kernel/printk/printk.c John Ogness 2022-04-21 2947 *
a699449bb13b70b kernel/printk/printk.c John Ogness 2022-04-21 2948 * Returns true when there was at least one usable console and all messages
a699449bb13b70b kernel/printk/printk.c John Ogness 2022-04-21 2949 * were flushed to all usable consoles. A returned false informs the caller
a699449bb13b70b kernel/printk/printk.c John Ogness 2022-04-21 2950 * that everything was not flushed (either there were no usable consoles or
a699449bb13b70b kernel/printk/printk.c John Ogness 2022-04-21 2951 * another context has taken over printing or it is a panic situation and this
5831788afb17b89 kernel/printk/printk.c Petr Mladek 2022-06-23 2952 * is not the panic CPU). Regardless the reason, the caller should assume it
5831788afb17b89 kernel/printk/printk.c Petr Mladek 2022-06-23 2953 * is not useful to immediately try again.
a699449bb13b70b kernel/printk/printk.c John Ogness 2022-04-21 2954 *
a699449bb13b70b kernel/printk/printk.c John Ogness 2022-04-21 2955 * Requires the console_lock.
a699449bb13b70b kernel/printk/printk.c John Ogness 2022-04-21 2956 */
a699449bb13b70b kernel/printk/printk.c John Ogness 2022-04-21 2957 static bool console_flush_all(bool do_cond_resched, u64 *next_seq, bool *handover)
a699449bb13b70b kernel/printk/printk.c John Ogness 2022-04-21 2958 {
a699449bb13b70b kernel/printk/printk.c John Ogness 2022-04-21 2959 bool any_usable = false;
a699449bb13b70b kernel/printk/printk.c John Ogness 2022-04-21 2960 struct console *con;
a699449bb13b70b kernel/printk/printk.c John Ogness 2022-04-21 2961 bool any_progress;
fc956ae0de7fa25 kernel/printk/printk.c John Ogness 2022-11-16 2962 int cookie;
a699449bb13b70b kernel/printk/printk.c John Ogness 2022-04-21 2963
a699449bb13b70b kernel/printk/printk.c John Ogness 2022-04-21 2964 *next_seq = 0;
a699449bb13b70b kernel/printk/printk.c John Ogness 2022-04-21 2965 *handover = false;
a699449bb13b70b kernel/printk/printk.c John Ogness 2022-04-21 2966
a699449bb13b70b kernel/printk/printk.c John Ogness 2022-04-21 2967 do {
a699449bb13b70b kernel/printk/printk.c John Ogness 2022-04-21 2968 any_progress = false;
a699449bb13b70b kernel/printk/printk.c John Ogness 2022-04-21 2969
fc956ae0de7fa25 kernel/printk/printk.c John Ogness 2022-11-16 2970 cookie = console_srcu_read_lock();
fc956ae0de7fa25 kernel/printk/printk.c John Ogness 2022-11-16 2971 for_each_console_srcu(con) {
cfa886eee9834d5 kernel/printk/printk.c Thomas Gleixner 2023-03-02 2972 short flags = console_srcu_read_flags(con);
a699449bb13b70b kernel/printk/printk.c John Ogness 2022-04-21 2973 bool progress;
a699449bb13b70b kernel/printk/printk.c John Ogness 2022-04-21 2974
cfa886eee9834d5 kernel/printk/printk.c Thomas Gleixner 2023-03-02 2975 /* console_flush_all() is only for legacy consoles. */
cfa886eee9834d5 kernel/printk/printk.c Thomas Gleixner 2023-03-02 2976 if (flags & CON_NO_BKL)
cfa886eee9834d5 kernel/printk/printk.c Thomas Gleixner 2023-03-02 2977 continue;
cfa886eee9834d5 kernel/printk/printk.c Thomas Gleixner 2023-03-02 2978
cfa886eee9834d5 kernel/printk/printk.c Thomas Gleixner 2023-03-02 @2979 if (!console_is_usable(con, flags))
a699449bb13b70b kernel/printk/printk.c John Ogness 2022-04-21 2980 continue;
a699449bb13b70b kernel/printk/printk.c John Ogness 2022-04-21 2981 any_usable = true;
a699449bb13b70b kernel/printk/printk.c John Ogness 2022-04-21 2982
daaab5b5bba36a5 kernel/printk/printk.c John Ogness 2023-01-09 2983 progress = console_emit_next_record(con, handover, cookie);
fc956ae0de7fa25 kernel/printk/printk.c John Ogness 2022-11-16 2984
fc956ae0de7fa25 kernel/printk/printk.c John Ogness 2022-11-16 2985 /*
fc956ae0de7fa25 kernel/printk/printk.c John Ogness 2022-11-16 2986 * If a handover has occurred, the SRCU read lock
fc956ae0de7fa25 kernel/printk/printk.c John Ogness 2022-11-16 2987 * is already released.
fc956ae0de7fa25 kernel/printk/printk.c John Ogness 2022-11-16 2988 */
a699449bb13b70b kernel/printk/printk.c John Ogness 2022-04-21 2989 if (*handover)
a699449bb13b70b kernel/printk/printk.c John Ogness 2022-04-21 2990 return false;
a699449bb13b70b kernel/printk/printk.c John Ogness 2022-04-21 2991
a699449bb13b70b kernel/printk/printk.c John Ogness 2022-04-21 2992 /* Track the next of the highest seq flushed. */
a699449bb13b70b kernel/printk/printk.c John Ogness 2022-04-21 2993 if (con->seq > *next_seq)
a699449bb13b70b kernel/printk/printk.c John Ogness 2022-04-21 2994 *next_seq = con->seq;
8d91f8b15361dfb kernel/printk/printk.c Tejun Heo 2016-01-15 2995
a699449bb13b70b kernel/printk/printk.c John Ogness 2022-04-21 2996 if (!progress)
a699449bb13b70b kernel/printk/printk.c John Ogness 2022-04-21 2997 continue;
a699449bb13b70b kernel/printk/printk.c John Ogness 2022-04-21 2998 any_progress = true;
a699449bb13b70b kernel/printk/printk.c John Ogness 2022-04-21 2999
a699449bb13b70b kernel/printk/printk.c John Ogness 2022-04-21 3000 /* Allow panic_cpu to take over the consoles safely. */
8ebc476fd51e6c0 kernel/printk/printk.c Stephen Brennan 2022-02-02 3001 if (abandon_console_lock_in_panic())
fc956ae0de7fa25 kernel/printk/printk.c John Ogness 2022-11-16 3002 goto abandon;
8ebc476fd51e6c0 kernel/printk/printk.c Stephen Brennan 2022-02-02 3003
8d91f8b15361dfb kernel/printk/printk.c Tejun Heo 2016-01-15 3004 if (do_cond_resched)
8d91f8b15361dfb kernel/printk/printk.c Tejun Heo 2016-01-15 3005 cond_resched();
^1da177e4c3f415 kernel/printk.c Linus Torvalds 2005-04-16 3006 }
fc956ae0de7fa25 kernel/printk/printk.c John Ogness 2022-11-16 3007 console_srcu_read_unlock(cookie);
a699449bb13b70b kernel/printk/printk.c John Ogness 2022-04-21 3008 } while (any_progress);
dbdda842fe96f89 kernel/printk/printk.c Steven Rostedt (VMware 2018-01-10 3009)
a699449bb13b70b kernel/printk/printk.c John Ogness 2022-04-21 3010 return any_usable;
fc956ae0de7fa25 kernel/printk/printk.c John Ogness 2022-11-16 3011
fc956ae0de7fa25 kernel/printk/printk.c John Ogness 2022-11-16 3012 abandon:
fc956ae0de7fa25 kernel/printk/printk.c John Ogness 2022-11-16 3013 console_srcu_read_unlock(cookie);
fc956ae0de7fa25 kernel/printk/printk.c John Ogness 2022-11-16 3014 return false;
a699449bb13b70b kernel/printk/printk.c John Ogness 2022-04-21 3015 }
fe3d8ad31cf51b0 kernel/printk.c Feng Tang 2011-03-22 3016

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https://github.com/intel/lkp-tests