summaryrefslogtreecommitdiff
path: root/fs/io_uring.c
diff options
context:
space:
mode:
authorJens Axboe <axboe@kernel.dk>2019-12-28 15:39:54 -0700
committerJens Axboe <axboe@kernel.dk>2020-01-20 17:04:02 -0700
commit8110c1a6212e430a84edd2b83fe9043def8b743e (patch)
tree3b7df2807aebe7cec855965c2a077898651e81cf /fs/io_uring.c
parentc6ca97b30c47c7ad36107d3764bb4dc37026d171 (diff)
io_uring: add support for IORING_SETUP_CLAMP
Some applications like to start small in terms of ring size, and then ramp up as needed. This is a bit tricky to do currently, since we don't advertise the max ring size. This adds IORING_SETUP_CLAMP. If set, and the values for SQ or CQ ring size exceed what we support, then clamp them at the max values instead of returning -EINVAL. Since we return the chosen ring sizes after setup, no further changes are needed on the application side. io_uring already changes the ring sizes if the application doesn't ask for power-of-two sizes, for example. Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'fs/io_uring.c')
-rw-r--r--fs/io_uring.c17
1 files changed, 14 insertions, 3 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 1fbe3eb78d08..7c44b0ef10d7 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -6234,8 +6234,13 @@ static int io_uring_create(unsigned entries, struct io_uring_params *p)
bool account_mem;
int ret;
- if (!entries || entries > IORING_MAX_ENTRIES)
+ if (!entries)
return -EINVAL;
+ if (entries > IORING_MAX_ENTRIES) {
+ if (!(p->flags & IORING_SETUP_CLAMP))
+ return -EINVAL;
+ entries = IORING_MAX_ENTRIES;
+ }
/*
* Use twice as many entries for the CQ ring. It's possible for the
@@ -6252,8 +6257,13 @@ static int io_uring_create(unsigned entries, struct io_uring_params *p)
* to a power-of-two, if it isn't already. We do NOT impose
* any cq vs sq ring sizing.
*/
- if (p->cq_entries < p->sq_entries || p->cq_entries > IORING_MAX_CQ_ENTRIES)
+ if (p->cq_entries < p->sq_entries)
return -EINVAL;
+ if (p->cq_entries > IORING_MAX_CQ_ENTRIES) {
+ if (!(p->flags & IORING_SETUP_CLAMP))
+ return -EINVAL;
+ p->cq_entries = IORING_MAX_CQ_ENTRIES;
+ }
p->cq_entries = roundup_pow_of_two(p->cq_entries);
} else {
p->cq_entries = 2 * p->sq_entries;
@@ -6345,7 +6355,8 @@ static long io_uring_setup(u32 entries, struct io_uring_params __user *params)
}
if (p.flags & ~(IORING_SETUP_IOPOLL | IORING_SETUP_SQPOLL |
- IORING_SETUP_SQ_AFF | IORING_SETUP_CQSIZE))
+ IORING_SETUP_SQ_AFF | IORING_SETUP_CQSIZE |
+ IORING_SETUP_CLAMP))
return -EINVAL;
ret = io_uring_create(entries, &p);