From nobody Wed Jan 5 06:39:01 2022 X-Original-To: freebsd-current@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 1FAEC192FC3F for ; Wed, 5 Jan 2022 06:39:13 +0000 (UTC) (envelope-from wlosh@bsdimp.com) Received: from mail-ua1-x92f.google.com (mail-ua1-x92f.google.com [IPv6:2607:f8b0:4864:20::92f]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (2048 bits) client-digest SHA256) (Client CN "smtp.gmail.com", Issuer "GTS CA 1D4" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4JTKZn02H6z3hF7 for ; Wed, 5 Jan 2022 06:39:12 +0000 (UTC) (envelope-from wlosh@bsdimp.com) Received: by mail-ua1-x92f.google.com with SMTP id v12so55487348uar.7 for ; Tue, 04 Jan 2022 22:39:12 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bsdimp-com.20210112.gappssmtp.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=/DRo01XLJkRFPG6vauwFaUHGieZtXM/VxYPMkp8EMuM=; b=4P7hGxvsY+MjR0JYy9psojqOqe/C6RT/M/31Ibc/cmXAdyprVBwqja4GOJK981zkOc IezWCAcQFQp4d+cLRCl3RPJsnSj+D4gF8SjPam4jpZ1QlERcBeeCcoaNp/jWERAujrJG dMIw23ikk588OCk5YtTQ3vSqNVYETT8TlL3Tm5nzTADQ2fsoqHBZI4amOFdXMAshpQHF PaSQjuiSpdWK3yUN+qp8FHa3EvRpUrQAq4E7ni45/jVod5MKec3Na7NAIwmkfZSD+wjM JU6vH8SihOTGTouuVII51d8nuPE9zG5OpRDpfIZlx8WlGcpg39jCta/XEtm2RsZ1BlYb mZVg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=/DRo01XLJkRFPG6vauwFaUHGieZtXM/VxYPMkp8EMuM=; b=e4koJTiJFkxvTghrJGdQsMnax7GraBVkOhWnJfxZg+OZPlREWUgl2r1ZDKRqDKNaLj LuTVg6IL0Ti+bF3ei2juF2QTjKnaJw3/OdF4V7A4/u5DfPbhaRxJqCw865axiyz6Irch aNHSllRZhFh5ijAtlIzZ1FEQIT5q6VU4QAHDTH9yRi4TURrn219uoZ9Rl6sdImbDJSOO 1zu0vip6S/J6OH3s6C39gG96M/w9lQKbseQvA4J6DgEpi3R6a74ZWP0warAiWa9b9+Sx 70kZhiw+7hBYM02YU+CxUL+sUeiULlFA87RlIHjwbAcx/ql7QTnte1vnxrRUreCU1ngN wf6A== X-Gm-Message-State: AOAM533xHmWPemls4MkDuy/04QCXsmrKOHNcTEnCwk95FO9IywOmzk/S vrvL6Qlpvm63haojeCLbWcU3OyEqPRhGx3b5akr4dD3RCWU= X-Google-Smtp-Source: ABdhPJzwaFjb5QX87Zvr3IZCl63SOc2+KwrByarEyMJbHYEnLI6sZy2JiKTGaeqZTBVdkFiyQ7clrKbgDwc12LjhpoQ= X-Received: by 2002:a05:6102:ed3:: with SMTP id m19mr17154074vst.68.1641364752144; Tue, 04 Jan 2022 22:39:12 -0800 (PST) List-Id: Discussions about the use of FreeBSD-current List-Archive: https://lists.freebsd.org/archives/freebsd-current List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-current@freebsd.org MIME-Version: 1.0 References: In-Reply-To: From: Warner Losh Date: Tue, 4 Jan 2022 23:39:01 -0700 Message-ID: Subject: Re: atkbd_timeout() period? To: Alexander Motin Cc: "freebsd-current@freebsd.org" Content-Type: multipart/alternative; boundary="000000000000ffafd105d4d002a1" X-Rspamd-Queue-Id: 4JTKZn02H6z3hF7 X-Spamd-Bar: ---- Authentication-Results: mx1.freebsd.org; none X-Spamd-Result: default: False [-4.00 / 15.00]; REPLY(-4.00)[] X-ThisMailContainsUnwantedMimeParts: N --000000000000ffafd105d4d002a1 Content-Type: text/plain; charset="UTF-8" On Tue, Jan 4, 2022 at 10:42 PM Alexander Motin wrote: > Hi, > > As I see, one of the most active threaded callouts on idle VMware VM and > some hardware is atkbd_timeout(), called 10 times per second. Plus it > is also one of few remaining non-MP-safe callouts. According to the > comment it seems to be only a workaround for some lost interrupts. That > makes me thing: is it really needed to run so often and so accurate, or > may be we could reduce it to 1-2 times per second? Or may be it can be > avoided somehow 20 years later? > Yea, we can likely just trash it and wait for people to complain about the keyboard being hung. I doubt we'll get any complaints because Xaccel 2.1 was quite a long time ago... It is no longer relevant and the original conditions that caused the lost interrupts are likely long gone... And if they aren't, we'll get a reproducible test case to judge what the right workaround should be. Warner --000000000000ffafd105d4d002a1 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable


=
On Tue, Jan 4, 2022 at 10:42 PM Alexa= nder Motin <mav@freebsd.org> w= rote:
Hi,

As I see, one of the most active threaded callouts on idle VMware VM and some hardware is atkbd_timeout(), called 10 times per second.=C2=A0 Plus it=
is also one of few remaining non-MP-safe callouts.=C2=A0 According to the comment it seems to be only a workaround for some lost interrupts.=C2=A0 Th= at
makes me thing: is it really needed to run so often and so accurate, or
may be we could reduce it to 1-2 times per second?=C2=A0 Or may be it can b= e
avoided somehow 20 years later?

Yea, we= can likely just trash it and wait for people to complain about the
keyboard being hung. I doubt we'll get any complaints because=C2=A0X= accel 2.1
was quite a long time ago... It is no longer relevant a= nd the original conditions
that caused the lost interrupts are li= kely long gone...

And if they aren't, we'l= l get a reproducible test case to judge what the right workaround
should be.

Warner

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