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| author | Jens Axboe <axboe@kernel.dk> | 2024-02-25 16:01:03 -0700 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2024-02-25 16:01:03 -0700 |
| commit | 41c8d9aa3dfc37d5430f7dd26c77454dc456f501 (patch) | |
| tree | 3d9907287a01b2095dd6805bf3846961b785246b | |
| parent | 295cef3eb2847f564a467f9d1b21d192f3a15b13 (diff) | |
| download | liburing-41c8d9aa3dfc37d5430f7dd26c77454dc456f501.tar.gz | |
man/io_uring_setup: mention that the submit on overflow depends on kernel
Fixes: https://github.com/axboe/liburing/issues/1063
Signed-off-by: Jens Axboe <axboe@kernel.dk>
| -rw-r--r-- | man/io_uring_setup.2 | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/man/io_uring_setup.2 b/man/io_uring_setup.2 index 82119fd8..c86f2e73 100644 --- a/man/io_uring_setup.2 +++ b/man/io_uring_setup.2 @@ -350,10 +350,12 @@ calls down from three to two. Available since kernel 5.4. .TP .B IORING_FEAT_NODROP If this flag is set, io_uring supports almost never dropping completion events. -If a completion event occurs and the CQ ring is full, the kernel stores -the event internally until such a time that the CQ ring has room for more -entries. If this overflow condition is entered, attempting to submit more -IO will fail with the +A dropped event can only occur if the kernel runs out of memory, in which case +you have worse problems than a lost event. Your application and others will +likely get OOM killed anyway. If a completion event occurs and the CQ ring is +full, the kernel stores the event internally until such a time that the CQ ring +has room for more entries. In earlier kernels, if this overflow condition is +entered, attempting to submit more IO would fail with the .B -EBUSY error value, if it can't flush the overflown events to the CQ ring. If this happens, the application must reap events from the CQ ring and attempt the |