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From:   Toke =?utf-8?Q?H=C3=B8iland-J=C3=B8rgensen?= <toke@redhat.com>
To:     Johannes Berg <johannes@sipsolutions.net>,
        linux-wireless@vger.kernel.org
Subject: Re: [PATCH] net/fq_impl: Switch to kvmalloc() for memory allocation
In-Reply-To: <0690b548e233fba3758df0ce1eeca1c0803a62c4.camel@sipsolutions.net>
References: <20191105154951.546285-1-toke@redhat.com> <0690b548e233fba3758df0ce1eeca1c0803a62c4.camel@sipsolutions.net>
Date:   Tue, 05 Nov 2019 16:56:07 +0100
Message-ID: <8736f2jp0o.fsf@toke.dk>
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Sender: linux-wireless-owner@vger.kernel.org
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Johannes Berg <johannes@sipsolutions.net> writes:

> On Tue, 2019-11-05 at 16:49 +0100, Toke H=C3=B8iland-J=C3=B8rgensen wrote=
:
>> The FQ implementation used by mac80211 allocates memory using kmalloc(),
>> which can fail; and Johannes reported that this actually happens in
>> practice.
>>=20
>> To avoid this, switch the allocation to kvmalloc() instead; this also
>> brings fq_impl in line with all the FQ qdiscs.
>>=20
>> Fixes: 557fc4a09803 ("fq: add fair queuing framework")
>> Reported-by: Johannes Berg <johannes@sipsolutions.net>
>> Signed-off-by: Toke H=C3=B8iland-J=C3=B8rgensen <toke@redhat.com>
>> ---
>>  include/net/fq_impl.h | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>=20
>> diff --git a/include/net/fq_impl.h b/include/net/fq_impl.h
>> index 107c0d700ed6..d3873db91c71 100644
>> --- a/include/net/fq_impl.h
>> +++ b/include/net/fq_impl.h
>> @@ -313,7 +313,7 @@ static int fq_init(struct fq *fq, int flows_cnt)
>>  =09fq->limit =3D 8192;
>>  =09fq->memory_limit =3D 16 << 20; /* 16 MBytes */
>> =20
>> -=09fq->flows =3D kcalloc(fq->flows_cnt, sizeof(fq->flows[0]), GFP_KERNE=
L);
>> +=09fq->flows =3D kvcalloc(fq->flows_cnt, sizeof(fq->flows[0]), GFP_KERN=
EL);
>
> You need a corresponding kvfree(), no?

Oh, right, of course; silly me. Guess I was a bit too trigger-happy on
the nice one-character patch ;)

Will send a v2

-Toke