From: Jens Axboe <[email protected]>
To: Vito Caputo <[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: Sun, 19 Sep 2021 08:16:36 -0600 [thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>
On 9/18/21 10:15 PM, Vito Caputo wrote:
> 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.
Yes, may as well. I've pushed a change that makes it incremental and
doesn't trigger it unless we hit EMFILE.
--
Jens Axboe
next prev parent reply other threads:[~2021-09-19 14:16 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
2021-09-19 14:16 ` Jens Axboe [this message]
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
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
[email protected] \
[email protected] \
[email protected] \
[email protected] \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox