Date: Thu, 24 Jun 2010 11:47:56 -0400 From: Boris Kochergin <spawk@acm.poly.edu> To: Sam Leffler <sam@freebsd.org> Cc: freebsd-net@freebsd.org, stef@memberwebs.com Subject: Re: kmem_map too small panics with Soekris/Atheros access point [ath rate control] Message-ID: <4C237E2C.3080103@acm.poly.edu> In-Reply-To: <4AB1D7C2.5010403@freebsd.org> References: <4A8C3557.20002@acm.poly.edu> <4AA03A41.1080200@acm.poly.edu> <4AB1A086.4090303@acm.poly.edu> <4AB1D7C2.5010403@freebsd.org>
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Sam Leffler wrote:
> Boris Kochergin wrote:
>
>> Stef Walter wrote:
>>
>>> Boris Kochergin wrote:
>>>
>>>
>> I, too, recall the days when you had multiple rate-control algorithms to
>> choose from, but that doesn't appear to be the case anymore. As a
>> workaround, I wrote a little script that checks if that part of the
>> driver is using more than 200 KiB of memory and run it every minute via
>> cron. It seems to be doing its job so far:
>>
>
> You can still select the ath rate control module. Static kernel config
> is unchanged; for modules you must export ATH_RATE=onoe or similar
> (check modules/ath/Makefile). Please file a PR if this does not work.
>
> Sam
>
(I had to go do some other stuff, but better late than never?)
Thanks. That does indeed work, but the problem persists with other
rate-control algorithms (I've upgraded most of the access points to
8.0-R, where the problem does not appear to exist, and upgraded one to
7.3-R for continued testing--this is where it still happens). I've
instrumented the memory-allocation bits in the ath and net80211 code
where MALLOC/malloc was called with a type of M_80211_NODE. I've tracked
the leak down to one of two allocations never being freed:
Line 595 of /usr/src/sys/net80211/ieee80211_node.c:
MALLOC(ni, struct ieee80211_node *, sizeof(struct ieee80211_node),
M_80211_NODE, M_NOWAIT | M_ZERO);
Line 3164 of /usr/src/sys/dev/ath/if_ath.c:
an = malloc(space, M_80211_NODE, M_NOWAIT|M_ZERO);
It looks like both are supposed to be freed by node_free() in
/usr/src/sys/net80211/ieee80211_node.c, but there is some code path
where that doesn't happen, and should. Hopefully, this helps someone
familiar with the code track it down. I may try it at some point, but it
intimidates me somewhat.
-Boris
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