From owner-freebsd-net@freebsd.org Wed Dec 21 19:15:15 2016 Return-Path: Delivered-To: freebsd-net@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 802C3C8B62D for ; Wed, 21 Dec 2016 19:15:15 +0000 (UTC) (envelope-from v.maffione@gmail.com) Received: from mail-oi0-x243.google.com (mail-oi0-x243.google.com [IPv6:2607:f8b0:4003:c06::243]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 43D8D1A8F; Wed, 21 Dec 2016 19:15:15 +0000 (UTC) (envelope-from v.maffione@gmail.com) Received: by mail-oi0-x243.google.com with SMTP id 3so959235oih.1; Wed, 21 Dec 2016 11:15:15 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=RrZ7RmAjJmLZhTV8ZUsup4NFLqM8WSqCp0LWXTXhnWA=; b=Bug6KmtbUY3ZO3dMbEJWiP898ywv5AkkGT5QKOry527QctP+tzSwQwErCN7HTnSwRf /NyPMKx35qvVBjIko31fiqoMwH4fkXBgGPWOX2nUokL0uKTawES+DtzheZfdUtmtzDN7 rL68/JJ3G6lf1Ykh8t5h3UIMoxSMBBxOMRseYSOCyhOdwtiKNBwjZEZD0JtAq1KdcVGb calerw0jTm6QBGFBipEAWkjPMCQnssxb0AK5q9irGiocQOGu+MXkR6G04PWRpmCjkIkb 9muIfNFUhJEJ63SP2l9QMZT91mYeL55QmQCVyYacc3dKbbf7eyAnZ22RbmJw6MPG00qB ad5A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=RrZ7RmAjJmLZhTV8ZUsup4NFLqM8WSqCp0LWXTXhnWA=; b=TaCGRg3jqt70YkfWFyyAmcCO0s6m4bAcO2jjSBMAxE1tPAi1pF3ISUltUFgN40vnFE E21hGP1Oemu0VMjUYP1Dn4EHRNqXgHay9nE/MMGjvKDDBITmnQnX/8vmnMseuGIEKN5e ws8GCr1bVlGy7qk6M54zo/hmV9AU7y84LSgH1g/9tZcmeGebqpUvlR+YGi9rdFgfIK0M A47qokHeIrKUhJjCvLuTi+EY20Wo5CZSMuW/SkOTtr3Wsd2b3S7hXLB6GaRs1NFMJwbD +0DyDnwKtktIbkTwG/nsWi+/0vbI4EyK1FAKuJ8IaaHvoj/rjOT8cb3j4nJTTDIM1NSW ikFw== X-Gm-Message-State: AIkVDXKlyBLqgziplxkmLcW1d+hKZFRlWOG2M9yRrkFZZ2AWsIukJLcOqoDvt8uW08lcj+rNf4DxJznJyJZtsg== X-Received: by 10.157.20.235 with SMTP id r40mr3224582otr.143.1482347714490; Wed, 21 Dec 2016 11:15:14 -0800 (PST) MIME-Version: 1.0 Received: by 10.157.45.200 with HTTP; Wed, 21 Dec 2016 11:15:14 -0800 (PST) In-Reply-To: References: <20161217222812.GA4979@ox> From: Vincenzo Maffione Date: Wed, 21 Dec 2016 20:15:14 +0100 Message-ID: Subject: Re: cxgbe's native netmap support broken since r307394 To: Adrian Chadd Cc: Navdeep Parhar , "freebsd-net@freebsd.org" , Luigi Rizzo , Giuseppe Lettieri Content-Type: text/plain; charset=UTF-8 X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 21 Dec 2016 19:15:15 -0000 Hi, There is no commit related to that in the FreeBSD svn or git. The fix has been published to the github netmap repository here (branch master): https://github.com/luigirizzo/netmap What we should do is to import all the recent updates from the github into HEAD. I can prepare a patch for HEAD, if you wish. Just let me know. Cheers, Vincenzo 2016-12-20 21:45 GMT+01:00 Adrian Chadd : > hi, > > What's the commit? We should get it into -HEAD asap. > > > -adrian > > > On 20 December 2016 at 01:25, Vincenzo Maffione wrote: >> Ok, applied to the netmap github repo. >> This fix will be published when Luigi does the next commit on FreeBSD. >> >> Cheers, >> Vincenzo >> >> 2016-12-19 20:05 GMT+01:00 Navdeep Parhar : >>> IFNET_RLOCK will work, thanks. >>> >>> Navdeep >>> >>> On Mon, Dec 19, 2016 at 3:21 AM, Vincenzo Maffione wrote: >>>> Hi Navdeep, >>>> >>>> Indeed, we have reviewed the code, and we think it is ok to >>>> implement nm_os_ifnet_lock() with IFNET_RLOCK(), instead of using >>>> IFNET_WLOCK(). >>>> Since IFNET_RLOCK() results into sx_slock(), this should fix the issue. >>>> >>>> On FreeBSD, this locking is needed to protect a flag read by nm_iszombie(). >>>> However, on Linux the same lock is also needed to protect the call to >>>> the nm_hw_register() callback, so we prefer to have an "unified" >>>> locking scheme, i.e. always calling nm_hw_register under the lock. >>>> >>>> Does this make sense to you? Would it be easy for you to make a quick >>>> test by replacing IFNET_WLOCK with IFNET_RLOCK? >>>> >>>> Thanks, >>>> Vincenzo >>>> >>>> 2016-12-17 23:28 GMT+01:00 Navdeep Parhar : >>>>> Luigi, Vincenzo, >>>>> >>>>> The last major update to netmap (r307394 and followups) broke cxgbe's >>>>> native netmap support. The problem is that netmap_hw_reg now holds an >>>>> rw_lock around the driver's netmap_on/off routines. It has always been >>>>> safe for the driver to sleep during these operations but now it panics >>>>> instead. >>>>> >>>>> Why is IFNET_WLOCK needed here? It seems like a regression to disallow >>>>> sleep on the control path. >>>>> >>>>> Regards, >>>>> Navdeep >>>>> >>>>> begin_synchronized_op with the following non-sleepable locks held: >>>>> exclusive rw ifnet_rw (ifnet_rw) r = 0 (0xffffffff8271d680) locked @ >>>>> /root/ws/head/sys/dev/netmap/netmap_freebsd.c:95 >>>>> stack backtrace: >>>>> #0 0xffffffff810837a5 at witness_debugger+0xe5 >>>>> #1 0xffffffff81084d88 at witness_warn+0x3b8 >>>>> #2 0xffffffff83ef2bcc at begin_synchronized_op+0x6c >>>>> #3 0xffffffff83f14beb at cxgbe_netmap_reg+0x5b >>>>> #4 0xffffffff809846f1 at netmap_hw_reg+0x81 >>>>> #5 0xffffffff809806de at netmap_do_regif+0x19e >>>>> #6 0xffffffff8098121d at netmap_ioctl+0x7ad >>>>> #7 0xffffffff8098682f at freebsd_netmap_ioctl+0x5f >>>> >>>> >>>> >>>> -- >>>> Vincenzo Maffione >>>> _______________________________________________ >>>> freebsd-net@freebsd.org mailing list >>>> https://lists.freebsd.org/mailman/listinfo/freebsd-net >>>> To unsubscribe, send any mail to "freebsd-net-unsubscribe@freebsd.org" >> >> >> >> -- >> Vincenzo Maffione >> _______________________________________________ >> freebsd-net@freebsd.org mailing list >> https://lists.freebsd.org/mailman/listinfo/freebsd-net >> To unsubscribe, send any mail to "freebsd-net-unsubscribe@freebsd.org" -- Vincenzo Maffione