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author | Pavel Begunkov <asml.silence@gmail.com> | 2021-02-04 13:52:08 +0000 |
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committer | Jens Axboe <axboe@kernel.dk> | 2021-02-04 08:05:46 -0700 |
commit | 5280f7e530f71ba85baf90169393196976ad0e52 (patch) | |
tree | efdf0f85b6f1f0b3f167091566701131de8afbf5 /fs/io-wq.c | |
parent | ea64ec02b31d5b05ae94ac4d57e38f8a02117c76 (diff) | |
download | lwn-5280f7e530f71ba85baf90169393196976ad0e52.tar.gz lwn-5280f7e530f71ba85baf90169393196976ad0e52.zip |
io_uring/io-wq: return 2-step work swap scheme
Saving one lock/unlock for io-wq is not super important, but adds some
ugliness in the code. More important, atomic decs not turning it to zero
for some archs won't give the right ordering/barriers so the
io_steal_work() may pretty easily get subtly and completely broken.
Return back 2-step io-wq work exchange and clean it up.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'fs/io-wq.c')
-rw-r--r-- | fs/io-wq.c | 16 |
1 files changed, 6 insertions, 10 deletions
diff --git a/fs/io-wq.c b/fs/io-wq.c index 2e2f14f42bf2..63ef195b1acb 100644 --- a/fs/io-wq.c +++ b/fs/io-wq.c @@ -555,23 +555,21 @@ get_next: /* handle a whole dependent link */ do { - struct io_wq_work *old_work, *next_hashed, *linked; + struct io_wq_work *next_hashed, *linked; unsigned int hash = io_get_work_hash(work); next_hashed = wq_next_work(work); io_impersonate_work(worker, work); + wq->do_work(work); + io_assign_current_work(worker, NULL); - old_work = work; - linked = wq->do_work(work); - + linked = wq->free_work(work); work = next_hashed; if (!work && linked && !io_wq_is_hashed(linked)) { work = linked; linked = NULL; } io_assign_current_work(worker, work); - wq->free_work(old_work); - if (linked) io_wqe_enqueue(wqe, linked); @@ -850,11 +848,9 @@ static void io_run_cancel(struct io_wq_work *work, struct io_wqe *wqe) struct io_wq *wq = wqe->wq; do { - struct io_wq_work *old_work = work; - work->flags |= IO_WQ_WORK_CANCEL; - work = wq->do_work(work); - wq->free_work(old_work); + wq->do_work(work); + work = wq->free_work(work); } while (work); } |