From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <4CD33F0C.1050403@domain.hid> Date: Fri, 05 Nov 2010 00:17:32 +0100 From: Jan Kiszka MIME-Version: 1.0 References: <4CC82C8D.3080808@domain.hid> <4CD14B1E.4000707@domain.hid> <4CD14C92.90901@domain.hid> <4CD14DBC.3060505@domain.hid> <4CD1509A.3000908@domain.hid> <4CD152F3.4080203@domain.hid> <4CD16654.6080704@domain.hid> <4CD18782.7090607@domain.hid> <4CD191EE.7000604@domain.hid> <4CD1936E.50203@domain.hid> <4CD1BA29.9000303@domain.hid> <1288816871.1842.84.camel@domain.hid> <4CD1DC1B.8060407@domain.hid> <4CD1DE12.5010309@domain.hid> <4CD1E890.5010702@domain.hid> <4CD1EC2F.4040603@domain.hid> <4CD1ED16.8030103@domain.hid> <4CD1EDA8.10007@domain.hid> <4CD1F33C.5070208@domain.hid> <4CD1F3F5.5080505@domain.hid> <4CD1F4FE.9020908@domain.hid> <4CD1F69B.9070100@domain.hid> <4CD1F906.1070703@domain.hid> <4CD1FABD.1080301@domain.hid> <4CD2612C.2070507@domain.hid> <4CD279F7.7070502@domain.hid> <4CD27C46.8010302@domain.hid> <4CD27DC2.7060607@domain.hid> <4CD2A96B.3080001@domain.hid> <4CD2B2A7.9010900@domain.hid> <4CD2C50F.1090604@domain.hid> <4CD32E76.3080004@domain.hid> In-Reply-To: <4CD32E76.3080004@domain.hid> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig1525102AEEEDE03C4491194C" Sender: jan.kiszka@domain.hid Subject: Re: [Xenomai-core] Potential problem with rt_eepro100 List-Id: Xenomai life and development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Gilles Chanteperdrix Cc: "xenomai@xenomai.org" This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig1525102AEEEDE03C4491194C Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Am 04.11.2010 23:06, Gilles Chanteperdrix wrote: > Jan Kiszka wrote: >>>> At first sight, here you are more breaking things than cleaning them= =2E >>> Still, it has the SMP record for my test program, still runs with ftr= ace=20 >>> on (after 2 hours, where it previously failed after maximum 23 minute= s). >> >> My version was indeed still buggy, I'm reworking it ATM. >> >>> If I get the gist of Jan's changes, they are (using the IPI to transf= er=20 >>> one bit of information: your cpu needs to reschedule): >>> >>> xnsched_set_resched: >>> - setbits((__sched__)->status, XNRESCHED); >>> >>> xnpod_schedule_handler: >>> + xnsched_set_resched(sched); >>> =09 >>> If you (we?) decide to keep the debug checks, under what circumstance= s=20 >>> would the current check trigger (in laymans language, that I'll be ab= le=20 >>> to understand)? >> >> That's actually what /me is wondering as well. I do not see yet how yo= u >> can reliably detect a missed reschedule reliably (that was the purpose= >> of the debug check) given the racy nature between signaling resched an= d >> processing the resched hints. >=20 > The purpose of the debugging change is to detect a change of the > scheduler state which was not followed by setting the XNRESCHED bit. But that is nucleus business, nothing skins can screw up (as long as they do not misuse APIs). > Getting it to work is relatively simple: we add a "scheduler change set= > remotely" bit to the sched structure which is NOT in the status bit, se= t > this bit when changing a remote sched (under nklock). In the debug chec= k > code, if the scheduler state changed, and the XNRESCHED bit is not set,= > only consider this a but if this new bit is not set. All this is > compiled out if the debug is not enabled. I still see no benefit in this check. Where to you want to place the bit set? Aren't that just the same locations where xnsched_set_[self_]resched already is today? But maybe you can provide some motivating bug scenarios, real ones of the past or realistic ones of the future. Jan --------------enig1525102AEEEDE03C4491194C Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.15 (GNU/Linux) Comment: Using GnuPG with SUSE - http://enigmail.mozdev.org/ iEYEARECAAYFAkzTPxEACgkQitSsb3rl5xSYoACeLXleakLsOXZ+ATtPMS0iyNmE 6qMAnihPNZ4KOE5MaXxs9Kc+JgJ95bW3 =u8Vk -----END PGP SIGNATURE----- --------------enig1525102AEEEDE03C4491194C--