Commit 3bc217ffe6774e7971d6a7ce6350ce806ebab044
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8bdd3f8a69
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block: kill swap_io_context()
It blindly copies everything in the io_context, including the lock. That doesn't work so well for either lock ordering or lockdep. There seems zero point in swapping io contexts on a request to request merge, so the best point of action is to just remove it. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Showing 3 changed files with 0 additions and 24 deletions Side-by-side Diff
block/as-iosched.c
| ... | ... | @@ -1268,22 +1268,8 @@ |
| 1268 | 1268 | */ |
| 1269 | 1269 | if (!list_empty(&req->queuelist) && !list_empty(&next->queuelist)) { |
| 1270 | 1270 | if (time_before(rq_fifo_time(next), rq_fifo_time(req))) { |
| 1271 | - struct io_context *rioc = RQ_IOC(req); | |
| 1272 | - struct io_context *nioc = RQ_IOC(next); | |
| 1273 | - | |
| 1274 | 1271 | list_move(&req->queuelist, &next->queuelist); |
| 1275 | 1272 | rq_set_fifo_time(req, rq_fifo_time(next)); |
| 1276 | - /* | |
| 1277 | - * Don't copy here but swap, because when anext is | |
| 1278 | - * removed below, it must contain the unused context | |
| 1279 | - */ | |
| 1280 | - if (rioc != nioc) { | |
| 1281 | - double_spin_lock(&rioc->lock, &nioc->lock, | |
| 1282 | - rioc < nioc); | |
| 1283 | - swap_io_context(&rioc, &nioc); | |
| 1284 | - double_spin_unlock(&rioc->lock, &nioc->lock, | |
| 1285 | - rioc < nioc); | |
| 1286 | - } | |
| 1287 | 1273 | } |
| 1288 | 1274 | } |
| 1289 | 1275 |
block/blk-ioc.c
| ... | ... | @@ -176,15 +176,6 @@ |
| 176 | 176 | } |
| 177 | 177 | EXPORT_SYMBOL(copy_io_context); |
| 178 | 178 | |
| 179 | -void swap_io_context(struct io_context **ioc1, struct io_context **ioc2) | |
| 180 | -{ | |
| 181 | - struct io_context *temp; | |
| 182 | - temp = *ioc1; | |
| 183 | - *ioc1 = *ioc2; | |
| 184 | - *ioc2 = temp; | |
| 185 | -} | |
| 186 | -EXPORT_SYMBOL(swap_io_context); | |
| 187 | - | |
| 188 | 179 | int __init blk_ioc_init(void) |
| 189 | 180 | { |
| 190 | 181 | iocontext_cachep = kmem_cache_create("blkdev_ioc", |
include/linux/blkdev.h
| ... | ... | @@ -39,7 +39,6 @@ |
| 39 | 39 | struct io_context *get_io_context(gfp_t gfp_flags, int node); |
| 40 | 40 | struct io_context *alloc_io_context(gfp_t gfp_flags, int node); |
| 41 | 41 | void copy_io_context(struct io_context **pdst, struct io_context **psrc); |
| 42 | -void swap_io_context(struct io_context **ioc1, struct io_context **ioc2); | |
| 43 | 42 | |
| 44 | 43 | struct request; |
| 45 | 44 | typedef void (rq_end_io_fn)(struct request *, int); |