From: Vito Caputo <[email protected]>
To: Jens Axboe <[email protected]>
Cc: io-uring <[email protected]>
Subject: Re: [BUG? liburing] io_uring_register_files_update with liburing 2.0 on 5.13.17
Date: Sat, 18 Sep 2021 21:15:46 -0700 [thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>
On Sat, Sep 18, 2021 at 05:40:51PM -0600, Jens Axboe wrote:
> On 9/18/21 5:37 PM, Jens Axboe wrote:
> >> and it failed with the same as before...
> >>
> >> io_uring_register(13, IORING_REGISTER_FILES, [-1, -1, -1, 3, 4, 5, 6, 7, 8,
> >> 9, 10, 11, 12, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
> >> -1, -1, -1, -1,
> >> -1, ...], 32768) = -1 EMFILE (Too many open files)
> >>
> >> if you want i can debug it for you tomorrow? (in london)
> >
> > Nah that's fine, I think it's just because you have other files opened
> > too. We bump the cur limit _to_ 'nr', but that leaves no room for anyone
> > else. Would be my guess. It works fine for the test case I ran here, but
> > your case may be different. Does it work if you just make it:
> >
> > rlim.rlim_cur += nr;
> >
> > instead?
>
> Specifically, just something like the below incremental. If rlim_cur
> _seems_ big enough, leave it alone. If not, add the amount we need to
> cur. And don't do any error checking here, let's leave failure to the
> kernel.
>
> diff --git a/src/register.c b/src/register.c
> index bab42d0..7597ec1 100644
> --- a/src/register.c
> +++ b/src/register.c
> @@ -126,9 +126,7 @@ static int bump_rlimit_nofile(unsigned nr)
> if (getrlimit(RLIMIT_NOFILE, &rlim) < 0)
> return -errno;
> if (rlim.rlim_cur < nr) {
> - if (nr > rlim.rlim_max)
> - return -EMFILE;
> - rlim.rlim_cur = nr;
> + rlim.rlim_cur += nr;
> setrlimit(RLIMIT_NOFILE, &rlim);
> }
>
>
Perhaps it makes more sense to only incur the getrlimit() cost on the
errno=EMFILE path? As in bump the ulimit and retry the operation on
failure, but when things are OK don't do any of this.
Regards,
Vito Caputo
next prev parent reply other threads:[~2021-09-19 4:23 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-18 13:41 [BUG? liburing] io_uring_register_files_update with liburing 2.0 on 5.13.17 Victor Stewart
2021-09-18 14:41 ` Jens Axboe
2021-09-18 20:13 ` Victor Stewart
2021-09-18 20:26 ` Jens Axboe
2021-09-18 20:38 ` Jens Axboe
2021-09-18 21:55 ` Victor Stewart
2021-09-18 22:21 ` Jens Axboe
2021-09-18 23:19 ` Victor Stewart
2021-09-18 23:23 ` Victor Stewart
2021-09-18 23:37 ` Jens Axboe
2021-09-18 23:40 ` Jens Axboe
2021-09-19 4:15 ` Vito Caputo [this message]
2021-09-19 14:16 ` Jens Axboe
2021-09-20 12:51 ` Victor Stewart
2021-09-20 13:10 ` Jens Axboe
2021-09-20 13:19 ` Victor Stewart
2021-09-19 11:56 ` Pavel Begunkov
2021-09-19 14:24 ` Jens Axboe
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