Re: [PATCH v7 RESENT] io_uring: releasing CPU resources when polling
From: kernel test robot
Date: Thu Aug 08 2024 - 12:31:29 EST
Hi hexue,
kernel test robot noticed the following build warnings:
[auto build test WARNING on linus/master]
[also build test WARNING on v6.11-rc2 next-20240808]
[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/hexue/io_uring-releasing-CPU-resources-when-polling/20240808-153455
base: linus/master
patch link: https://lore.kernel.org/r/20240808071712.2429842-1-xue01.he%40samsung.com
patch subject: [PATCH v7 RESENT] io_uring: releasing CPU resources when polling
config: alpha-defconfig (https://download.01.org/0day-ci/archive/20240809/202408090038.uF18SUul-lkp@xxxxxxxxx/config)
compiler: alpha-linux-gcc (GCC) 13.3.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240809/202408090038.uF18SUul-lkp@xxxxxxxxx/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@xxxxxxxxx>
| Closes: https://lore.kernel.org/oe-kbuild-all/202408090038.uF18SUul-lkp@xxxxxxxxx/
All warnings (new ones prefixed by >>):
io_uring/rw.c: In function 'io_do_iopoll':
>> io_uring/rw.c:1210:30: warning: unused variable 'file' [-Wunused-variable]
1210 | struct file *file = req->file;
| ^~~~
vim +/file +1210 io_uring/rw.c
e61753df273102 hexue 2024-08-08 1193
f3b44f92e59a80 Jens Axboe 2022-06-13 1194 int io_do_iopoll(struct io_ring_ctx *ctx, bool force_nonspin)
f3b44f92e59a80 Jens Axboe 2022-06-13 1195 {
f3b44f92e59a80 Jens Axboe 2022-06-13 1196 struct io_wq_work_node *pos, *start, *prev;
54bdd67d0f8848 Keith Busch 2023-03-20 1197 unsigned int poll_flags = 0;
f3b44f92e59a80 Jens Axboe 2022-06-13 1198 DEFINE_IO_COMP_BATCH(iob);
f3b44f92e59a80 Jens Axboe 2022-06-13 1199 int nr_events = 0;
f3b44f92e59a80 Jens Axboe 2022-06-13 1200
f3b44f92e59a80 Jens Axboe 2022-06-13 1201 /*
f3b44f92e59a80 Jens Axboe 2022-06-13 1202 * Only spin for completions if we don't have multiple devices hanging
f3b44f92e59a80 Jens Axboe 2022-06-13 1203 * off our complete list.
f3b44f92e59a80 Jens Axboe 2022-06-13 1204 */
f3b44f92e59a80 Jens Axboe 2022-06-13 1205 if (ctx->poll_multi_queue || force_nonspin)
f3b44f92e59a80 Jens Axboe 2022-06-13 1206 poll_flags |= BLK_POLL_ONESHOT;
f3b44f92e59a80 Jens Axboe 2022-06-13 1207
f3b44f92e59a80 Jens Axboe 2022-06-13 1208 wq_list_for_each(pos, start, &ctx->iopoll_list) {
f3b44f92e59a80 Jens Axboe 2022-06-13 1209 struct io_kiocb *req = container_of(pos, struct io_kiocb, comp_list);
a1119fb0711591 Jens Axboe 2022-09-02 @1210 struct file *file = req->file;
f3b44f92e59a80 Jens Axboe 2022-06-13 1211 int ret;
f3b44f92e59a80 Jens Axboe 2022-06-13 1212
f3b44f92e59a80 Jens Axboe 2022-06-13 1213 /*
f3b44f92e59a80 Jens Axboe 2022-06-13 1214 * Move completed and retryable entries to our local lists.
f3b44f92e59a80 Jens Axboe 2022-06-13 1215 * If we find a request that requires polling, break out
f3b44f92e59a80 Jens Axboe 2022-06-13 1216 * and complete those lists first, if we have entries there.
f3b44f92e59a80 Jens Axboe 2022-06-13 1217 */
f3b44f92e59a80 Jens Axboe 2022-06-13 1218 if (READ_ONCE(req->iopoll_completed))
f3b44f92e59a80 Jens Axboe 2022-06-13 1219 break;
f3b44f92e59a80 Jens Axboe 2022-06-13 1220
e61753df273102 hexue 2024-08-08 1221 if (ctx->flags & IORING_SETUP_HY_POLL)
e61753df273102 hexue 2024-08-08 1222 ret = io_uring_hybrid_poll(req, &iob, poll_flags);
e61753df273102 hexue 2024-08-08 1223 else
e61753df273102 hexue 2024-08-08 1224 ret = io_uring_classic_poll(req, &iob, poll_flags);
5756a3a7e713bc Kanchan Joshi 2022-08-23 1225
f3b44f92e59a80 Jens Axboe 2022-06-13 1226 if (unlikely(ret < 0))
f3b44f92e59a80 Jens Axboe 2022-06-13 1227 return ret;
f3b44f92e59a80 Jens Axboe 2022-06-13 1228 else if (ret)
f3b44f92e59a80 Jens Axboe 2022-06-13 1229 poll_flags |= BLK_POLL_ONESHOT;
f3b44f92e59a80 Jens Axboe 2022-06-13 1230
f3b44f92e59a80 Jens Axboe 2022-06-13 1231 /* iopoll may have completed current req */
f3b44f92e59a80 Jens Axboe 2022-06-13 1232 if (!rq_list_empty(iob.req_list) ||
f3b44f92e59a80 Jens Axboe 2022-06-13 1233 READ_ONCE(req->iopoll_completed))
f3b44f92e59a80 Jens Axboe 2022-06-13 1234 break;
f3b44f92e59a80 Jens Axboe 2022-06-13 1235 }
f3b44f92e59a80 Jens Axboe 2022-06-13 1236
f3b44f92e59a80 Jens Axboe 2022-06-13 1237 if (!rq_list_empty(iob.req_list))
f3b44f92e59a80 Jens Axboe 2022-06-13 1238 iob.complete(&iob);
f3b44f92e59a80 Jens Axboe 2022-06-13 1239 else if (!pos)
f3b44f92e59a80 Jens Axboe 2022-06-13 1240 return 0;
f3b44f92e59a80 Jens Axboe 2022-06-13 1241
f3b44f92e59a80 Jens Axboe 2022-06-13 1242 prev = start;
f3b44f92e59a80 Jens Axboe 2022-06-13 1243 wq_list_for_each_resume(pos, prev) {
f3b44f92e59a80 Jens Axboe 2022-06-13 1244 struct io_kiocb *req = container_of(pos, struct io_kiocb, comp_list);
f3b44f92e59a80 Jens Axboe 2022-06-13 1245
f3b44f92e59a80 Jens Axboe 2022-06-13 1246 /* order with io_complete_rw_iopoll(), e.g. ->result updates */
f3b44f92e59a80 Jens Axboe 2022-06-13 1247 if (!smp_load_acquire(&req->iopoll_completed))
f3b44f92e59a80 Jens Axboe 2022-06-13 1248 break;
f3b44f92e59a80 Jens Axboe 2022-06-13 1249 nr_events++;
f3b44f92e59a80 Jens Axboe 2022-06-13 1250 req->cqe.flags = io_put_kbuf(req, 0);
a9165b83c1937e Jens Axboe 2024-03-18 1251 if (req->opcode != IORING_OP_URING_CMD)
a9165b83c1937e Jens Axboe 2024-03-18 1252 io_req_rw_cleanup(req, 0);
544d163d659d45 Pavel Begunkov 2023-01-12 1253 }
f3b44f92e59a80 Jens Axboe 2022-06-13 1254 if (unlikely(!nr_events))
f3b44f92e59a80 Jens Axboe 2022-06-13 1255 return 0;
f3b44f92e59a80 Jens Axboe 2022-06-13 1256
f3b44f92e59a80 Jens Axboe 2022-06-13 1257 pos = start ? start->next : ctx->iopoll_list.first;
f3b44f92e59a80 Jens Axboe 2022-06-13 1258 wq_list_cut(&ctx->iopoll_list, prev, start);
ec26c225f06f59 Pavel Begunkov 2023-08-24 1259
ec26c225f06f59 Pavel Begunkov 2023-08-24 1260 if (WARN_ON_ONCE(!wq_list_empty(&ctx->submit_state.compl_reqs)))
ec26c225f06f59 Pavel Begunkov 2023-08-24 1261 return 0;
ec26c225f06f59 Pavel Begunkov 2023-08-24 1262 ctx->submit_state.compl_reqs.first = pos;
ec26c225f06f59 Pavel Begunkov 2023-08-24 1263 __io_submit_flush_completions(ctx);
f3b44f92e59a80 Jens Axboe 2022-06-13 1264 return nr_events;
f3b44f92e59a80 Jens Axboe 2022-06-13 1265 }
a9165b83c1937e Jens Axboe 2024-03-18 1266
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