Re: [PATCH v2 06/11] blk-mq: Pass driver tags to blk_mq_clear_rq_mapping()

From: kernel test robot
Date: Mon Aug 09 2021 - 13:01:17 EST


Hi John,

I love your patch! Perhaps something to improve:

[auto build test WARNING on block/for-next]
[also build test WARNING on v5.14-rc5 next-20210809]
[cannot apply to mkp-scsi/for-next ceph-client/for-linus scsi/for-next]
[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]

url: https://github.com/0day-ci/linux/commits/John-Garry/blk-mq-Reduce-static-requests-memory-footprint-for-shared-sbitmap/20210809-223943
base: https://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux-block.git for-next
config: um-x86_64_defconfig (attached as .config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
reproduce (this is a W=1 build):
# https://github.com/0day-ci/linux/commit/535293cab26a196d29b64d9ce8a7274bfd1806d8
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review John-Garry/blk-mq-Reduce-static-requests-memory-footprint-for-shared-sbitmap/20210809-223943
git checkout 535293cab26a196d29b64d9ce8a7274bfd1806d8
# save the attached .config to linux build tree
make W=1 ARCH=um SUBARCH=x86_64

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@xxxxxxxxx>

All warnings (new ones prefixed by >>):

>> block/blk-mq.c:2313:6: warning: no previous prototype for 'blk_mq_clear_rq_mapping' [-Wmissing-prototypes]
2313 | void blk_mq_clear_rq_mapping(struct blk_mq_tags *drv_tags,
| ^~~~~~~~~~~~~~~~~~~~~~~


vim +/blk_mq_clear_rq_mapping +2313 block/blk-mq.c

2311
2312 /* called before freeing request pool in @tags */
> 2313 void blk_mq_clear_rq_mapping(struct blk_mq_tags *drv_tags,
2314 struct blk_mq_tags *tags)
2315 {
2316 struct page *page;
2317 unsigned long flags;
2318
2319 list_for_each_entry(page, &tags->page_list, lru) {
2320 unsigned long start = (unsigned long)page_address(page);
2321 unsigned long end = start + order_to_size(page->private);
2322 int i;
2323
2324 for (i = 0; i < drv_tags->nr_tags; i++) {
2325 struct request *rq = drv_tags->rqs[i];
2326 unsigned long rq_addr = (unsigned long)rq;
2327
2328 if (rq_addr >= start && rq_addr < end) {
2329 WARN_ON_ONCE(refcount_read(&rq->ref) != 0);
2330 cmpxchg(&drv_tags->rqs[i], rq, NULL);
2331 }
2332 }
2333 }
2334
2335 /*
2336 * Wait until all pending iteration is done.
2337 *
2338 * Request reference is cleared and it is guaranteed to be observed
2339 * after the ->lock is released.
2340 */
2341 spin_lock_irqsave(&drv_tags->lock, flags);
2342 spin_unlock_irqrestore(&drv_tags->lock, flags);
2343 }
2344

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx

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