From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:48451) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bwJUT-0001S6-8C for qemu-devel@nongnu.org; Mon, 17 Oct 2016 21:46:54 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bwJUS-0005mz-24 for qemu-devel@nongnu.org; Mon, 17 Oct 2016 21:46:53 -0400 Received: from ozlabs.org ([2401:3900:2:1::2]:49701) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1bwJUQ-0005gV-Qt for qemu-devel@nongnu.org; Mon, 17 Oct 2016 21:46:51 -0400 Date: Tue, 18 Oct 2016 12:40:02 +1100 From: David Gibson Message-ID: <20161018014002.GB25390@umbus.fritz.box> References: <1475541180-16363-1-git-send-email-aik@ozlabs.ru> <9a52afb0-79d1-0b53-a271-516724b766a6@ozlabs.ru> <3c486136-fee1-b0dc-4c7f-ec0e1ffe50bd@ozlabs.ru> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="3CF/MBslHFRhO8r/" Content-Disposition: inline In-Reply-To: <3c486136-fee1-b0dc-4c7f-ec0e1ffe50bd@ozlabs.ru> Subject: Re: [Qemu-devel] [PATCH qemu] sysemu: support up to 1024 vCPUs List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexey Kardashevskiy Cc: qemu-devel@nongnu.org, Greg Kurz --3CF/MBslHFRhO8r/ Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Oct 18, 2016 at 12:07:20PM +1100, Alexey Kardashevskiy wrote: > Ping, anyone? >=20 > I rather expected floods of mails on such a controversial topic :) I think it's the reverse of the bike-shed problem. Hardly anyone feels qualified to comment on it. It looks ok to me, but I just don't know if there are other subtle dependencies on the size of the cpumask buried in the code. Oh well, let's say: Reviewed-by: David Gibson and find any problems as they arise. Not sure who we need to convince to take this into their tree though. >=20 >=20 > On 11/10/16 09:19, Alexey Kardashevskiy wrote: > > Ping, anyone? > >=20 > >=20 > > On 04/10/16 11:33, Alexey Kardashevskiy wrote: > >> From: Greg Kurz > >> > >> Some systems can already provide more than 255 hardware threads. > >> > >> Bumping the QEMU limit to 1024 seems reasonable: > >> - it has no visible overhead in top; > >> - the limit itself has no effect on hot paths. > >> > >> Signed-off-by: Greg Kurz > >> Signed-off-by: Alexey Kardashevskiy > >> --- > >> include/sysemu/sysemu.h | 2 +- > >> 1 file changed, 1 insertion(+), 1 deletion(-) > >> > >> diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h > >> index ef2c50b..2ec0bd8 100644 > >> --- a/include/sysemu/sysemu.h > >> +++ b/include/sysemu/sysemu.h > >> @@ -173,7 +173,7 @@ extern int mem_prealloc; > >> * > >> * Note that cpu->get_arch_id() may be larger than MAX_CPUMASK_BITS. > >> */ > >> -#define MAX_CPUMASK_BITS 255 > >> +#define MAX_CPUMASK_BITS 1024 > >> =20 > >> #define MAX_OPTION_ROMS 16 > >> typedef struct QEMUOptionRom { > >> > >=20 > >=20 >=20 >=20 --=20 David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson --3CF/MBslHFRhO8r/ Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAEBCAAGBQJYBX1vAAoJEGw4ysog2bOS93UP/0GxDULF5zo9qUsfyna1Hury YaSn3ZVIZxIfDFpSAd+RQZZduW18wy3vhtUQZsOazv5bLTPwpy8/Idz4yPa9CWAn JZHwWMbWidEGrYwvUA/oNPObZkh83cpu2C1ngDKQYL79Pwrbn5H627sNFj2mfZAQ 39CYklP5k1XR2taecoc2qE1Y5dQm26P38LfYAKVqO2AWqyOo4OsRObB3LfZ+chBW ZErgTNYKfVlG7I50Jk5S2oXa/nhPXZM4F29N73YF083553KJJRAugapiwRGMWrvT vPu+C7Yv5eIc6v1ZgyY7oKmGWMCUK96kuiajTPuVdnwKZ7leHelFFszx8SF91tft fT3WkIqKSL5mPOeoqdjwSo5yOhhxvBJA/aEfAGqSlXI8hkQaTsfdQmSc/ez+1+jv t2uDqvApBZz/KYS7Pq1n0M7H41wTUwY9XiGgRVHYrTbwPQEGPdcj3+85hPICRXxL zY6XwlVgiBDAYWgLZ4mz/aCkvjErOoG0UTDomH8zuidz1F5ZOAyi621qEhYKSTJi acioxBFfkVBkswbKSXAIxd+n9NahFTqJOPhzD12p9lgnwUhiXHyF3OnZiFxzWwWn QlaFVfVJjCmZi1WUNV3UM4PNLvACRUIHZiEuSC3AE2LFkoSooE2O94xUIBccN4dH fH4g3DXxIVnXlh9/CFxa =ajDD -----END PGP SIGNATURE----- --3CF/MBslHFRhO8r/--