From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1JtRRY-0002cF-PF for qemu-devel@nongnu.org; Tue, 06 May 2008 13:59:12 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1JtRRX-0002bm-79 for qemu-devel@nongnu.org; Tue, 06 May 2008 13:59:12 -0400 Received: from [199.232.76.173] (port=60489 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1JtRRX-0002bi-2f for qemu-devel@nongnu.org; Tue, 06 May 2008 13:59:11 -0400 Received: from fmmailgate01.web.de ([217.72.192.221]) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1JtRRW-0003JW-Ky for qemu-devel@nongnu.org; Tue, 06 May 2008 13:59:10 -0400 Message-ID: <48209C67.9010801@web.de> Date: Tue, 06 May 2008 19:59:03 +0200 From: Jan Kiszka MIME-Version: 1.0 References: <481B6626.7010603@web.de> <481B80F0.8050705@web.de> <481D670D.6070602@web.de> <481DF561.4050709@web.de> <481E1001.3010703@web.de> <481F554B.1020100@web.de> In-Reply-To: Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enigD65D24BF156230C4582D5948" Sender: jan.kiszka@web.de Subject: [Qemu-devel] Re: [PATCH] alsaaudio: increase default buffer sizes Reply-To: qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: malc Cc: qemu-devel@nongnu.org This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enigD65D24BF156230C4582D5948 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable malc wrote: > On Mon, 5 May 2008, Jan Kiszka wrote: >=20 >> malc wrote: >>> On Sun, 4 May 2008, Jan Kiszka wrote: >>> >>>> Jan Kiszka wrote: >>>>> malc wrote: >>>>>> On Sun, 4 May 2008, Jan Kiszka wrote: >>>>>> >>> >>> [..snip..] >>> >>>>> >>>>> Yeah, great, that was the key! Find below the version that works >>>>> for me >>>>> (on 64 bit 8) ). It even obsoletes my buffer size patch. Please mer= ge! >>>> >>>> Declaring the buffer size tweak obsolete was too quick. I still need= >>>> more under certain guest load, but now I'm already fine with >>>> DEFAULT_BUFFER_SIZE=3D4096. Or all in one: >>> >>> I wonder if everyone will be happy with quadrupled latency, apart fro= m >> >> Hmm, I wonder about the scenario where this latency may actually hurt.= >> QEMU is not /that/ fast anyway. ;) >=20 > You would be surprised. Tell me more! :-> >=20 >> >>> you and this other user on some (kvm was it) mailing list there are n= o >>> huge outcries of dissatisfaction, then again i'm not sure how many >>> people >>> use ALSA+QEMU or QEMUs+AUDIO in general. >> >> I don't think many users are actually running QEMU (or KVM) against >> ALSA. You have to >> - manually enable it during configure >> - pass QEMU_AUDIO_DRV=3Dalsa (OSS remains default even if ALSA is on -= I >> ran into this trap first.) >=20 > I don't see how it's a trap. You can also enable esd or fmod drivers > in configure along with alsa, which one should be the default? For sure, you need this mechanism with >1 audio backends being enabled in parallel. It's just the question how one is supposed to find out about this additional requirement: $ grep -r QEMU_AUDIO_DRV qemu qemu/audio/audio.c: " set QEMU_AUDIO_DRV=3Dwav\n" qemu/audio/audio.c: " export QEMU_AUDIO_DRV=3Dwav\n" qemu/audio/audio.c: drvname =3D audio_get_conf_str ("QEMU_AUDIO_DR= V", NULL, &def); Am I missing some reference? Then sorry in advance. >=20 >> - possibly have to fix up your configuration with FIXED_FREQ and >> BUFFER_SIZE (as reported by >1 kvm users) until >> >> As OSS does not give us shared sound device access and, in the end, is= a >> deprecated API under Linux, my goal is to overcome remaining issues of= >> the ALSA support and then make /this/ the default one (under Linux). >> >=20 > Huh? Even OSS/lite that is/was shipping with default Linux gave me > "shared" sound, though i had a decent sound card with possibility to > open the same /dev/dsp 16 times (it actually had 16 sigmatel chips on > board). And the real OSS has vmix. And fwiw to have this wonderful > "shared" sound you have to configure "dmix" (or whatever its called) > too. Well, probably configurable as well with compat-OSS (real OSS is dead on Linux). The fact is that - not only for me - this sharing does not work out-of-the-box with OSS, while it does with ALSA. Don't ask me why, I'm not an expert on this, I'm rather looking at it from a "normal" user perspective. Jan --------------enigD65D24BF156230C4582D5948 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.4-svn0 (GNU/Linux) Comment: Using GnuPG with SUSE - http://enigmail.mozdev.org iD8DBQFIIJxsniDOoMHTA+kRAglbAKCDUpyW43AKDV0oAzvavLX6rdNFYQCfZbk1 5cZdp4PXVMrko1HOyEHjUIM= =PYDl -----END PGP SIGNATURE----- --------------enigD65D24BF156230C4582D5948--