diff mbox series

[v1,1/4] list: Introduce list_count() to count existing nodes

Message ID 20221114112842.38565-1-andriy.shevchenko@linux.intel.com
State New
Headers
Series [v1,1/4] list: Introduce list_count() to count existing nodes |

Commit Message

Andy Shevchenko Nov. 14, 2022, 11:28 a.m. UTC 
  Some of the existing users, and definitely will be new ones, want to
count existing nodes in the list. Provide a generic API for that.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 include/linux/list.h | 13 +++++++++++++
 1 file changed, 13 insertions(+)

Comments

kernel test robot Nov. 14, 2022, 3:38 p.m. UTC | #1 
Hi Andy,

I love your patch! Yet something to improve:

[auto build test ERROR on usb/usb-testing]
[also build test ERROR on usb/usb-next usb/usb-linus linus/master v6.1-rc5 next-20221114]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Andy-Shevchenko/list-Introduce-list_count-to-count-existing-nodes/20221114-193023
base:   https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing
patch link:    https://lore.kernel.org/r/20221114112842.38565-1-andriy.shevchenko%40linux.intel.com
patch subject: [PATCH v1 1/4] list: Introduce list_count() to count existing nodes
config: x86_64-rhel-8.3-func
compiler: gcc-11 (Debian 11.3.0-8) 11.3.0
reproduce (this is a W=1 build):
        # https://github.com/intel-lab-lkp/linux/commit/124813c325e31e99580c2aaef85bb3943e55c36e
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Andy-Shevchenko/list-Introduce-list_count-to-count-existing-nodes/20221114-193023
        git checkout 124813c325e31e99580c2aaef85bb3943e55c36e
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash drivers/gpu/drm/i915/

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

   In file included from include/linux/mutex.h:15,
                    from include/linux/seq_file.h:9,
                    from include/drm/drm_print.h:31,
                    from drivers/gpu/drm/i915/gt/intel_engine_cs.c:8:
>> include/linux/list.h:663:2: error: expected identifier or '(' before '{' token
     663 | ({                                      \
         |  ^
   drivers/gpu/drm/i915/gt/intel_engine_cs.c:2007:22: note: in expansion of macro 'list_count'
    2007 | static unsigned long list_count(struct list_head *list)
         |                      ^~~~~~~~~~


vim +663 include/linux/list.h

   557	
   558	/**
   559	 * list_next_entry - get the next element in list
   560	 * @pos:	the type * to cursor
   561	 * @member:	the name of the list_head within the struct.
   562	 */
   563	#define list_next_entry(pos, member) \
   564		list_entry((pos)->member.next, typeof(*(pos)), member)
   565	
   566	/**
   567	 * list_next_entry_circular - get the next element in list
   568	 * @pos:	the type * to cursor.
   569	 * @head:	the list head to take the element from.
   570	 * @member:	the name of the list_head within the struct.
   571	 *
   572	 * Wraparound if pos is the last element (return the first element).
   573	 * Note, that list is expected to be not empty.
   574	 */
   575	#define list_next_entry_circular(pos, head, member) \
   576		(list_is_last(&(pos)->member, head) ? \
   577		list_first_entry(head, typeof(*(pos)), member) : list_next_entry(pos, member))
   578	
   579	/**
   580	 * list_prev_entry - get the prev element in list
   581	 * @pos:	the type * to cursor
   582	 * @member:	the name of the list_head within the struct.
   583	 */
   584	#define list_prev_entry(pos, member) \
   585		list_entry((pos)->member.prev, typeof(*(pos)), member)
   586	
   587	/**
   588	 * list_prev_entry_circular - get the prev element in list
   589	 * @pos:	the type * to cursor.
   590	 * @head:	the list head to take the element from.
   591	 * @member:	the name of the list_head within the struct.
   592	 *
   593	 * Wraparound if pos is the first element (return the last element).
   594	 * Note, that list is expected to be not empty.
   595	 */
   596	#define list_prev_entry_circular(pos, head, member) \
   597		(list_is_first(&(pos)->member, head) ? \
   598		list_last_entry(head, typeof(*(pos)), member) : list_prev_entry(pos, member))
   599	
   600	/**
   601	 * list_for_each	-	iterate over a list
   602	 * @pos:	the &struct list_head to use as a loop cursor.
   603	 * @head:	the head for your list.
   604	 */
   605	#define list_for_each(pos, head) \
   606		for (pos = (head)->next; !list_is_head(pos, (head)); pos = pos->next)
   607	
   608	/**
   609	 * list_for_each_rcu - Iterate over a list in an RCU-safe fashion
   610	 * @pos:	the &struct list_head to use as a loop cursor.
   611	 * @head:	the head for your list.
   612	 */
   613	#define list_for_each_rcu(pos, head)		  \
   614		for (pos = rcu_dereference((head)->next); \
   615		     !list_is_head(pos, (head)); \
   616		     pos = rcu_dereference(pos->next))
   617	
   618	/**
   619	 * list_for_each_continue - continue iteration over a list
   620	 * @pos:	the &struct list_head to use as a loop cursor.
   621	 * @head:	the head for your list.
   622	 *
   623	 * Continue to iterate over a list, continuing after the current position.
   624	 */
   625	#define list_for_each_continue(pos, head) \
   626		for (pos = pos->next; !list_is_head(pos, (head)); pos = pos->next)
   627	
   628	/**
   629	 * list_for_each_prev	-	iterate over a list backwards
   630	 * @pos:	the &struct list_head to use as a loop cursor.
   631	 * @head:	the head for your list.
   632	 */
   633	#define list_for_each_prev(pos, head) \
   634		for (pos = (head)->prev; !list_is_head(pos, (head)); pos = pos->prev)
   635	
   636	/**
   637	 * list_for_each_safe - iterate over a list safe against removal of list entry
   638	 * @pos:	the &struct list_head to use as a loop cursor.
   639	 * @n:		another &struct list_head to use as temporary storage
   640	 * @head:	the head for your list.
   641	 */
   642	#define list_for_each_safe(pos, n, head) \
   643		for (pos = (head)->next, n = pos->next; \
   644		     !list_is_head(pos, (head)); \
   645		     pos = n, n = pos->next)
   646	
   647	/**
   648	 * list_for_each_prev_safe - iterate over a list backwards safe against removal of list entry
   649	 * @pos:	the &struct list_head to use as a loop cursor.
   650	 * @n:		another &struct list_head to use as temporary storage
   651	 * @head:	the head for your list.
   652	 */
   653	#define list_for_each_prev_safe(pos, n, head) \
   654		for (pos = (head)->prev, n = pos->prev; \
   655		     !list_is_head(pos, (head)); \
   656		     pos = n, n = pos->prev)
   657	
   658	/**
   659	 * list_count - count nodes in the list
   660	 * @head:	the head for your list.
   661	 */
   662	#define list_count(head)		\
 > 663	({					\
   664		struct list_head *__tmp;	\
   665		size_t __i = 0;			\
   666		list_for_each(__tmp, head)	\
   667			__i++;			\
   668		__i;				\
   669	})
   670
kernel test robot Nov. 14, 2022, 3:38 p.m. UTC | #2 
Hi Andy,

I love your patch! Yet something to improve:

[auto build test ERROR on usb/usb-testing]
[also build test ERROR on usb/usb-next usb/usb-linus linus/master v6.1-rc5 next-20221114]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Andy-Shevchenko/list-Introduce-list_count-to-count-existing-nodes/20221114-193023
base:   https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing
patch link:    https://lore.kernel.org/r/20221114112842.38565-1-andriy.shevchenko%40linux.intel.com
patch subject: [PATCH v1 1/4] list: Introduce list_count() to count existing nodes
config: i386-defconfig
compiler: gcc-11 (Debian 11.3.0-8) 11.3.0
reproduce (this is a W=1 build):
        # https://github.com/intel-lab-lkp/linux/commit/124813c325e31e99580c2aaef85bb3943e55c36e
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Andy-Shevchenko/list-Introduce-list_count-to-count-existing-nodes/20221114-193023
        git checkout 124813c325e31e99580c2aaef85bb3943e55c36e
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

   In file included from include/linux/mutex.h:15,
                    from include/linux/seq_file.h:9,
                    from include/drm/drm_print.h:31,
                    from drivers/gpu/drm/i915/gt/intel_engine_cs.c:8:
   include/linux/list.h:663:2: error: expected identifier or '(' before '{' token
     663 | ({                                      \
         |  ^
   drivers/gpu/drm/i915/gt/intel_engine_cs.c:2007:22: note: in expansion of macro 'list_count'
    2007 | static unsigned long list_count(struct list_head *list)
         |                      ^~~~~~~~~~
   drivers/gpu/drm/i915/gt/intel_engine_cs.c: In function 'intel_engine_dump':
>> drivers/gpu/drm/i915/gt/intel_engine_cs.c:2192:38: error: format '%lu' expects argument of type 'long unsigned int', but argument 3 has type 'size_t' {aka 'unsigned int'} [-Werror=format=]
    2192 |         drm_printf(m, "\tOn hold?: %lu\n",
         |                                    ~~^
         |                                      |
         |                                      long unsigned int
         |                                    %u
   cc1: all warnings being treated as errors


vim +2192 drivers/gpu/drm/i915/gt/intel_engine_cs.c

dc0dad365c5ed8 drivers/gpu/drm/i915/gt/intel_engine_cs.c John Harrison   2021-07-26  2144  
3ceda3a4a85633 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2018-02-12  2145  void intel_engine_dump(struct intel_engine_cs *engine,
3ceda3a4a85633 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2018-02-12  2146  		       struct drm_printer *m,
3ceda3a4a85633 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2018-02-12  2147  		       const char *header, ...)
3ceda3a4a85633 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2018-02-12  2148  {
3ceda3a4a85633 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2018-02-12  2149  	struct i915_gpu_error * const error = &engine->i915->gpu_error;
0212bdef5a4de3 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2019-01-15  2150  	struct i915_request *rq;
538ef96b9dae7f drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2019-01-14  2151  	intel_wakeref_t wakeref;
cfe7288c276e35 drivers/gpu/drm/i915/gt/intel_engine_cs.c Chris Wilson    2019-07-15  2152  	unsigned long flags;
4fb33953438bf3 drivers/gpu/drm/i915/gt/intel_engine_cs.c Chris Wilson    2020-06-19  2153  	ktime_t dummy;
3ceda3a4a85633 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2018-02-12  2154  
3ceda3a4a85633 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2018-02-12  2155  	if (header) {
3ceda3a4a85633 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2018-02-12  2156  		va_list ap;
3ceda3a4a85633 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2018-02-12  2157  
3ceda3a4a85633 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2018-02-12  2158  		va_start(ap, header);
3ceda3a4a85633 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2018-02-12  2159  		drm_vprintf(m, header, &ap);
3ceda3a4a85633 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2018-02-12  2160  		va_end(ap);
3ceda3a4a85633 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2018-02-12  2161  	}
3ceda3a4a85633 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2018-02-12  2162  
cb823ed9915b0d drivers/gpu/drm/i915/gt/intel_engine_cs.c Chris Wilson    2019-07-12  2163  	if (intel_gt_is_wedged(engine->gt))
3ceda3a4a85633 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2018-02-12  2164  		drm_printf(m, "*** WEDGED ***\n");
3ceda3a4a85633 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2018-02-12  2165  
79ffac8599c4d8 drivers/gpu/drm/i915/gt/intel_engine_cs.c Chris Wilson    2019-04-24  2166  	drm_printf(m, "\tAwake? %d\n", atomic_read(&engine->wakeref.count));
7983990ca94ab6 drivers/gpu/drm/i915/gt/intel_engine_cs.c Chris Wilson    2019-11-28  2167  	drm_printf(m, "\tBarriers?: %s\n",
01fabda8e3d62e drivers/gpu/drm/i915/gt/intel_engine_cs.c Lucas De Marchi 2022-02-25  2168  		   str_yes_no(!llist_empty(&engine->barrier_tasks)));
b81e4d9b594188 drivers/gpu/drm/i915/gt/intel_engine_cs.c Chris Wilson    2019-12-19  2169  	drm_printf(m, "\tLatency: %luus\n",
b81e4d9b594188 drivers/gpu/drm/i915/gt/intel_engine_cs.c Chris Wilson    2019-12-19  2170  		   ewma__engine_latency_read(&engine->latency));
4fb33953438bf3 drivers/gpu/drm/i915/gt/intel_engine_cs.c Chris Wilson    2020-06-19  2171  	if (intel_engine_supports_stats(engine))
4fb33953438bf3 drivers/gpu/drm/i915/gt/intel_engine_cs.c Chris Wilson    2020-06-19  2172  		drm_printf(m, "\tRuntime: %llums\n",
4fb33953438bf3 drivers/gpu/drm/i915/gt/intel_engine_cs.c Chris Wilson    2020-06-19  2173  			   ktime_to_ms(intel_engine_get_busy_time(engine,
4fb33953438bf3 drivers/gpu/drm/i915/gt/intel_engine_cs.c Chris Wilson    2020-06-19  2174  								  &dummy)));
ac4fc5b38d1abc drivers/gpu/drm/i915/gt/intel_engine_cs.c Chris Wilson    2020-06-05  2175  	drm_printf(m, "\tForcewake: %x domains, %d active\n",
2c421896adb099 drivers/gpu/drm/i915/gt/intel_engine_cs.c Chris Wilson    2021-01-15  2176  		   engine->fw_domain, READ_ONCE(engine->fw_active));
058179e72e0956 drivers/gpu/drm/i915/gt/intel_engine_cs.c Chris Wilson    2019-10-23  2177  
058179e72e0956 drivers/gpu/drm/i915/gt/intel_engine_cs.c Chris Wilson    2019-10-23  2178  	rcu_read_lock();
058179e72e0956 drivers/gpu/drm/i915/gt/intel_engine_cs.c Chris Wilson    2019-10-23  2179  	rq = READ_ONCE(engine->heartbeat.systole);
058179e72e0956 drivers/gpu/drm/i915/gt/intel_engine_cs.c Chris Wilson    2019-10-23  2180  	if (rq)
058179e72e0956 drivers/gpu/drm/i915/gt/intel_engine_cs.c Chris Wilson    2019-10-23  2181  		drm_printf(m, "\tHeartbeat: %d ms ago\n",
058179e72e0956 drivers/gpu/drm/i915/gt/intel_engine_cs.c Chris Wilson    2019-10-23  2182  			   jiffies_to_msecs(jiffies - rq->emitted_jiffies));
058179e72e0956 drivers/gpu/drm/i915/gt/intel_engine_cs.c Chris Wilson    2019-10-23  2183  	rcu_read_unlock();
3ceda3a4a85633 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2018-02-12  2184  	drm_printf(m, "\tReset count: %d (global %d)\n",
3ceda3a4a85633 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2018-02-12  2185  		   i915_reset_engine_count(error, engine),
3ceda3a4a85633 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2018-02-12  2186  		   i915_reset_count(error));
0bda4b80d949d8 drivers/gpu/drm/i915/gt/intel_engine_cs.c Chris Wilson    2020-09-16  2187  	print_properties(engine, m);
3ceda3a4a85633 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2018-02-12  2188  
349a2bc5aae45f drivers/gpu/drm/i915/gt/intel_engine_cs.c Matthew Brost   2021-06-17  2189  	spin_lock_irqsave(&engine->sched_engine->lock, flags);
dc0dad365c5ed8 drivers/gpu/drm/i915/gt/intel_engine_cs.c John Harrison   2021-07-26  2190  	engine_dump_active_requests(engine, m);
83c317832eb186 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2018-06-14  2191  
349a2bc5aae45f drivers/gpu/drm/i915/gt/intel_engine_cs.c Matthew Brost   2021-06-17 @2192  	drm_printf(m, "\tOn hold?: %lu\n",
349a2bc5aae45f drivers/gpu/drm/i915/gt/intel_engine_cs.c Matthew Brost   2021-06-17  2193  		   list_count(&engine->sched_engine->hold));
349a2bc5aae45f drivers/gpu/drm/i915/gt/intel_engine_cs.c Matthew Brost   2021-06-17  2194  	spin_unlock_irqrestore(&engine->sched_engine->lock, flags);
3ceda3a4a85633 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2018-02-12  2195  
a4eb99a1d61754 drivers/gpu/drm/i915/gt/intel_engine_cs.c Chris Wilson    2019-08-13  2196  	drm_printf(m, "\tMMIO base:  0x%08x\n", engine->mmio_base);
cd6a851385be87 drivers/gpu/drm/i915/gt/intel_engine_cs.c Chris Wilson    2019-10-07  2197  	wakeref = intel_runtime_pm_get_if_in_use(engine->uncore->rpm);
538ef96b9dae7f drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2019-01-14  2198  	if (wakeref) {
3ceda3a4a85633 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2018-02-12  2199  		intel_engine_print_registers(engine, m);
cd6a851385be87 drivers/gpu/drm/i915/gt/intel_engine_cs.c Chris Wilson    2019-10-07  2200  		intel_runtime_pm_put(engine->uncore->rpm, wakeref);
3ceda3a4a85633 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2018-02-12  2201  	} else {
3ceda3a4a85633 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2018-02-12  2202  		drm_printf(m, "\tDevice is asleep; skipping register dump\n");
3ceda3a4a85633 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2018-02-12  2203  	}
f636edb214a5ff drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2017-10-09  2204  
1f0e785a9cc09b drivers/gpu/drm/i915/gt/intel_engine_cs.c Chris Wilson    2020-11-19  2205  	intel_execlists_show_requests(engine, m, i915_request_show, 8);
f636edb214a5ff drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2017-10-09  2206  
c1bf272857896d drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2017-12-22  2207  	drm_printf(m, "HWSP:\n");
0ca88ba0d6347c drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2019-01-28  2208  	hexdump(m, engine->status_page.addr, PAGE_SIZE);
c1bf272857896d drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2017-12-22  2209  
01fabda8e3d62e drivers/gpu/drm/i915/gt/intel_engine_cs.c Lucas De Marchi 2022-02-25  2210  	drm_printf(m, "Idle? %s\n", str_yes_no(intel_engine_is_idle(engine)));
52c0fdb25c7c91 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2019-01-29  2211  
52c0fdb25c7c91 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2019-01-29  2212  	intel_engine_print_breadcrumbs(engine, m);
f636edb214a5ff drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2017-10-09  2213  }
f636edb214a5ff drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2017-10-09  2214
Andy Shevchenko Nov. 14, 2022, 4:03 p.m. UTC | #3 
On Mon, Nov 14, 2022 at 11:38:04PM +0800, kernel test robot wrote:
> Hi Andy,
> 
> I love your patch! Yet something to improve:
> 
> [auto build test ERROR on usb/usb-testing]
> [also build test ERROR on usb/usb-next usb/usb-linus linus/master v6.1-rc5 next-20221114]
> [If your patch is applied to the wrong git tree, kindly drop us a note.
> And when submitting patch, we suggest to use '--base' as documented in
> https://git-scm.com/docs/git-format-patch#_base_tree_information]
> 
> url:    https://github.com/intel-lab-lkp/linux/commits/Andy-Shevchenko/list-Introduce-list_count-to-count-existing-nodes/20221114-193023
> base:   https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing
> patch link:    https://lore.kernel.org/r/20221114112842.38565-1-andriy.shevchenko%40linux.intel.com
> patch subject: [PATCH v1 1/4] list: Introduce list_count() to count existing nodes
> config: x86_64-rhel-8.3-func
> compiler: gcc-11 (Debian 11.3.0-8) 11.3.0
> reproduce (this is a W=1 build):
>         # https://github.com/intel-lab-lkp/linux/commit/124813c325e31e99580c2aaef85bb3943e55c36e
>         git remote add linux-review https://github.com/intel-lab-lkp/linux
>         git fetch --no-tags linux-review Andy-Shevchenko/list-Introduce-list_count-to-count-existing-nodes/20221114-193023
>         git checkout 124813c325e31e99580c2aaef85bb3943e55c36e
>         # save the config file
>         mkdir build_dir && cp config build_dir/.config
>         make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash drivers/gpu/drm/i915/
> 
> If you fix the issue, kindly add following tag where applicable
> | Reported-by: kernel test robot <lkp@intel.com>
> 
> All errors (new ones prefixed by >>):

Oh, nice! I will fix this for v2.
Matthew Wilcox Nov. 14, 2022, 5:47 p.m. UTC | #4 
On Mon, Nov 14, 2022 at 06:03:00PM +0200, Andy Shevchenko wrote:
> Oh, nice! I will fix this for v2.

list_count() is an antipattern.  I don't have any of the patches in
my inbox, so maybe there's a great reason for doing this, but my
immediate response is: NAK.
Andy Shevchenko Nov. 14, 2022, 5:57 p.m. UTC | #5 
On Mon, Nov 14, 2022 at 05:47:21PM +0000, Matthew Wilcox wrote:
> On Mon, Nov 14, 2022 at 06:03:00PM +0200, Andy Shevchenko wrote:
> > Oh, nice! I will fix this for v2.
> 
> list_count() is an antipattern.  I don't have any of the patches in
> my inbox, so maybe there's a great reason for doing this, but my
> immediate response is: NAK.

When we are trying to hide iterator variable in many cases, leaving the current
code alive will allow explicit access to it. If it's not a problem, why to
bother with the other list APIs then?
kernel test robot Nov. 14, 2022, 6:39 p.m. UTC | #6 
Hi Andy,

I love your patch! Perhaps something to improve:

[auto build test WARNING on usb/usb-testing]
[also build test WARNING on usb/usb-next usb/usb-linus linus/master v6.1-rc5 next-20221114]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Andy-Shevchenko/list-Introduce-list_count-to-count-existing-nodes/20221114-193023
base:   https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing
patch link:    https://lore.kernel.org/r/20221114112842.38565-1-andriy.shevchenko%40linux.intel.com
patch subject: [PATCH v1 1/4] list: Introduce list_count() to count existing nodes
config: i386-randconfig-a012-20221114
compiler: clang version 14.0.6 (https://github.com/llvm/llvm-project f28c006a5895fc0e329fe15fead81e37457cb1d1)
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/124813c325e31e99580c2aaef85bb3943e55c36e
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Andy-Shevchenko/list-Introduce-list_count-to-count-existing-nodes/20221114-193023
        git checkout 124813c325e31e99580c2aaef85bb3943e55c36e
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=i386 SHELL=/bin/bash drivers/gpu/drm/i915/

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

   drivers/gpu/drm/i915/gt/intel_engine_cs.c:2007:22: error: expected identifier or '('
   static unsigned long list_count(struct list_head *list)
                        ^
   include/linux/list.h:663:2: note: expanded from macro 'list_count'
   ({                                      \
    ^
   drivers/gpu/drm/i915/gt/intel_engine_cs.c:2007:22: error: expected ')'
   include/linux/list.h:663:2: note: expanded from macro 'list_count'
   ({                                      \
    ^
   drivers/gpu/drm/i915/gt/intel_engine_cs.c:2007:22: note: to match this '('
   include/linux/list.h:662:27: note: expanded from macro 'list_count'
   #define list_count(head)                \
                                           ^
>> drivers/gpu/drm/i915/gt/intel_engine_cs.c:2193:6: warning: format specifies type 'unsigned long' but the argument has type 'size_t' (aka 'unsigned int') [-Wformat]
                      list_count(&engine->sched_engine->hold));
                      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/list.h:662:27: note: expanded from macro 'list_count'
   #define list_count(head)                \
                                           ^
   1 warning and 2 errors generated.


vim +2193 drivers/gpu/drm/i915/gt/intel_engine_cs.c

dc0dad365c5ed8 drivers/gpu/drm/i915/gt/intel_engine_cs.c John Harrison   2021-07-26  2144  
3ceda3a4a85633 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2018-02-12  2145  void intel_engine_dump(struct intel_engine_cs *engine,
3ceda3a4a85633 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2018-02-12  2146  		       struct drm_printer *m,
3ceda3a4a85633 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2018-02-12  2147  		       const char *header, ...)
3ceda3a4a85633 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2018-02-12  2148  {
3ceda3a4a85633 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2018-02-12  2149  	struct i915_gpu_error * const error = &engine->i915->gpu_error;
0212bdef5a4de3 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2019-01-15  2150  	struct i915_request *rq;
538ef96b9dae7f drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2019-01-14  2151  	intel_wakeref_t wakeref;
cfe7288c276e35 drivers/gpu/drm/i915/gt/intel_engine_cs.c Chris Wilson    2019-07-15  2152  	unsigned long flags;
4fb33953438bf3 drivers/gpu/drm/i915/gt/intel_engine_cs.c Chris Wilson    2020-06-19  2153  	ktime_t dummy;
3ceda3a4a85633 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2018-02-12  2154  
3ceda3a4a85633 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2018-02-12  2155  	if (header) {
3ceda3a4a85633 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2018-02-12  2156  		va_list ap;
3ceda3a4a85633 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2018-02-12  2157  
3ceda3a4a85633 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2018-02-12  2158  		va_start(ap, header);
3ceda3a4a85633 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2018-02-12  2159  		drm_vprintf(m, header, &ap);
3ceda3a4a85633 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2018-02-12  2160  		va_end(ap);
3ceda3a4a85633 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2018-02-12  2161  	}
3ceda3a4a85633 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2018-02-12  2162  
cb823ed9915b0d drivers/gpu/drm/i915/gt/intel_engine_cs.c Chris Wilson    2019-07-12  2163  	if (intel_gt_is_wedged(engine->gt))
3ceda3a4a85633 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2018-02-12  2164  		drm_printf(m, "*** WEDGED ***\n");
3ceda3a4a85633 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2018-02-12  2165  
79ffac8599c4d8 drivers/gpu/drm/i915/gt/intel_engine_cs.c Chris Wilson    2019-04-24  2166  	drm_printf(m, "\tAwake? %d\n", atomic_read(&engine->wakeref.count));
7983990ca94ab6 drivers/gpu/drm/i915/gt/intel_engine_cs.c Chris Wilson    2019-11-28  2167  	drm_printf(m, "\tBarriers?: %s\n",
01fabda8e3d62e drivers/gpu/drm/i915/gt/intel_engine_cs.c Lucas De Marchi 2022-02-25  2168  		   str_yes_no(!llist_empty(&engine->barrier_tasks)));
b81e4d9b594188 drivers/gpu/drm/i915/gt/intel_engine_cs.c Chris Wilson    2019-12-19  2169  	drm_printf(m, "\tLatency: %luus\n",
b81e4d9b594188 drivers/gpu/drm/i915/gt/intel_engine_cs.c Chris Wilson    2019-12-19  2170  		   ewma__engine_latency_read(&engine->latency));
4fb33953438bf3 drivers/gpu/drm/i915/gt/intel_engine_cs.c Chris Wilson    2020-06-19  2171  	if (intel_engine_supports_stats(engine))
4fb33953438bf3 drivers/gpu/drm/i915/gt/intel_engine_cs.c Chris Wilson    2020-06-19  2172  		drm_printf(m, "\tRuntime: %llums\n",
4fb33953438bf3 drivers/gpu/drm/i915/gt/intel_engine_cs.c Chris Wilson    2020-06-19  2173  			   ktime_to_ms(intel_engine_get_busy_time(engine,
4fb33953438bf3 drivers/gpu/drm/i915/gt/intel_engine_cs.c Chris Wilson    2020-06-19  2174  								  &dummy)));
ac4fc5b38d1abc drivers/gpu/drm/i915/gt/intel_engine_cs.c Chris Wilson    2020-06-05  2175  	drm_printf(m, "\tForcewake: %x domains, %d active\n",
2c421896adb099 drivers/gpu/drm/i915/gt/intel_engine_cs.c Chris Wilson    2021-01-15  2176  		   engine->fw_domain, READ_ONCE(engine->fw_active));
058179e72e0956 drivers/gpu/drm/i915/gt/intel_engine_cs.c Chris Wilson    2019-10-23  2177  
058179e72e0956 drivers/gpu/drm/i915/gt/intel_engine_cs.c Chris Wilson    2019-10-23  2178  	rcu_read_lock();
058179e72e0956 drivers/gpu/drm/i915/gt/intel_engine_cs.c Chris Wilson    2019-10-23  2179  	rq = READ_ONCE(engine->heartbeat.systole);
058179e72e0956 drivers/gpu/drm/i915/gt/intel_engine_cs.c Chris Wilson    2019-10-23  2180  	if (rq)
058179e72e0956 drivers/gpu/drm/i915/gt/intel_engine_cs.c Chris Wilson    2019-10-23  2181  		drm_printf(m, "\tHeartbeat: %d ms ago\n",
058179e72e0956 drivers/gpu/drm/i915/gt/intel_engine_cs.c Chris Wilson    2019-10-23  2182  			   jiffies_to_msecs(jiffies - rq->emitted_jiffies));
058179e72e0956 drivers/gpu/drm/i915/gt/intel_engine_cs.c Chris Wilson    2019-10-23  2183  	rcu_read_unlock();
3ceda3a4a85633 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2018-02-12  2184  	drm_printf(m, "\tReset count: %d (global %d)\n",
3ceda3a4a85633 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2018-02-12  2185  		   i915_reset_engine_count(error, engine),
3ceda3a4a85633 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2018-02-12  2186  		   i915_reset_count(error));
0bda4b80d949d8 drivers/gpu/drm/i915/gt/intel_engine_cs.c Chris Wilson    2020-09-16  2187  	print_properties(engine, m);
3ceda3a4a85633 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2018-02-12  2188  
349a2bc5aae45f drivers/gpu/drm/i915/gt/intel_engine_cs.c Matthew Brost   2021-06-17  2189  	spin_lock_irqsave(&engine->sched_engine->lock, flags);
dc0dad365c5ed8 drivers/gpu/drm/i915/gt/intel_engine_cs.c John Harrison   2021-07-26  2190  	engine_dump_active_requests(engine, m);
83c317832eb186 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2018-06-14  2191  
349a2bc5aae45f drivers/gpu/drm/i915/gt/intel_engine_cs.c Matthew Brost   2021-06-17  2192  	drm_printf(m, "\tOn hold?: %lu\n",
349a2bc5aae45f drivers/gpu/drm/i915/gt/intel_engine_cs.c Matthew Brost   2021-06-17 @2193  		   list_count(&engine->sched_engine->hold));
349a2bc5aae45f drivers/gpu/drm/i915/gt/intel_engine_cs.c Matthew Brost   2021-06-17  2194  	spin_unlock_irqrestore(&engine->sched_engine->lock, flags);
3ceda3a4a85633 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2018-02-12  2195  
a4eb99a1d61754 drivers/gpu/drm/i915/gt/intel_engine_cs.c Chris Wilson    2019-08-13  2196  	drm_printf(m, "\tMMIO base:  0x%08x\n", engine->mmio_base);
cd6a851385be87 drivers/gpu/drm/i915/gt/intel_engine_cs.c Chris Wilson    2019-10-07  2197  	wakeref = intel_runtime_pm_get_if_in_use(engine->uncore->rpm);
538ef96b9dae7f drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2019-01-14  2198  	if (wakeref) {
3ceda3a4a85633 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2018-02-12  2199  		intel_engine_print_registers(engine, m);
cd6a851385be87 drivers/gpu/drm/i915/gt/intel_engine_cs.c Chris Wilson    2019-10-07  2200  		intel_runtime_pm_put(engine->uncore->rpm, wakeref);
3ceda3a4a85633 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2018-02-12  2201  	} else {
3ceda3a4a85633 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2018-02-12  2202  		drm_printf(m, "\tDevice is asleep; skipping register dump\n");
3ceda3a4a85633 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2018-02-12  2203  	}
f636edb214a5ff drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2017-10-09  2204  
1f0e785a9cc09b drivers/gpu/drm/i915/gt/intel_engine_cs.c Chris Wilson    2020-11-19  2205  	intel_execlists_show_requests(engine, m, i915_request_show, 8);
f636edb214a5ff drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2017-10-09  2206  
c1bf272857896d drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2017-12-22  2207  	drm_printf(m, "HWSP:\n");
0ca88ba0d6347c drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2019-01-28  2208  	hexdump(m, engine->status_page.addr, PAGE_SIZE);
c1bf272857896d drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2017-12-22  2209  
01fabda8e3d62e drivers/gpu/drm/i915/gt/intel_engine_cs.c Lucas De Marchi 2022-02-25  2210  	drm_printf(m, "Idle? %s\n", str_yes_no(intel_engine_is_idle(engine)));
52c0fdb25c7c91 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2019-01-29  2211  
52c0fdb25c7c91 drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2019-01-29  2212  	intel_engine_print_breadcrumbs(engine, m);
f636edb214a5ff drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2017-10-09  2213  }
f636edb214a5ff drivers/gpu/drm/i915/intel_engine_cs.c    Chris Wilson    2017-10-09  2214
diff mbox series

Patch

diff --git a/include/linux/list.h b/include/linux/list.h
index 61762054b4be..098eccf8c1b6 100644
--- a/include/linux/list.h
+++ b/include/linux/list.h
@@ -655,6 +655,19 @@  static inline void list_splice_tail_init(struct list_head *list,
 	     !list_is_head(pos, (head)); \
 	     pos = n, n = pos->prev)
 
+/**
+ * list_count - count nodes in the list
+ * @head:	the head for your list.
+ */
+#define list_count(head)		\
+({					\
+	struct list_head *__tmp;	\
+	size_t __i = 0;			\
+	list_for_each(__tmp, head)	\
+		__i++;			\
+	__i;				\
+})
+
 /**
  * list_entry_is_head - test if the entry points to the head of the list
  * @pos:	the type * to cursor