From: Jason Gunthorpe <jgg@nvidia.com>
To: Yasunori Goto <y-goto@fujitsu.com>
Cc: linux-rdma@vger.kernel.org, Doug Ledford <dledford@redhat.com>
Subject: Re: [PATCH] RDMA/core: EPERM should be returned when # of pined pages is over ulimit
Date: Thu, 19 Aug 2021 20:10:53 -0300 [thread overview]
Message-ID: <20210819231053.GA390234@nvidia.com> (raw)
In-Reply-To: <20210818082702.692117-1-y-goto@fujitsu.com>
On Wed, Aug 18, 2021 at 05:27:02PM +0900, Yasunori Goto wrote:
> Hello,
>
> When I started to use SoftRoCE, I'm very confused by
> ENOMEM error output even if I gave enough memory.
>
> I think EPERM is more suitable for uses to solve error rather than
> ENOMEM at here of ib_umem_get() when # of pinned pages is over ulimit.
> This is not "memory is not enough" problem, because driver can
> succeed to pin enough amount of pages, but it is larger than ulimit value.
>
> The hard limit of "max locked memory" can be changed by limit.conf.
> In addition, this checks also CAP_IPC_LOCK, it is indeed permmission check.
> So, I think the following patch.
>
> If there is a intention why ENOMEM is used here, please let me know.
> Otherwise, I'm glad if this is merged.
>
> Thanks.
>
>
> ---
> When # of pinned pages are larger than ulimit of "max locked memory"
> without CAP_IPC_LOCK, current ib_umem_get() returns ENOMEM.
> But it does not mean "not enough memory", because driver could succeed to
> pinned enough pages.
> This is just capability error. Even if a normal user is limited
> his/her # of pinned pages, system administrator can give permission
> by change hard limit of this ulimit value.
> To notify correct information to user, ib_umem_get()
> should return EPERM instead of ENOMEM at here.
I'm not convinced, can you find other places checking the ulimit and
list what codes they return?
Jason
next prev parent reply other threads:[~2021-08-19 23:10 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-18 8:27 [PATCH] RDMA/core: EPERM should be returned when # of pined pages is over ulimit Yasunori Goto
2021-08-19 23:10 ` Jason Gunthorpe [this message]
2021-08-20 0:36 ` Yasunori Goto
2021-08-20 8:45 ` Yasunori Goto
2021-08-26 13:32 ` Jason Gunthorpe
2021-08-27 0:08 ` Gotou, Yasunori/五島 康文
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