Date: Tue, 18 Sep 2007 07:33:35 +0300 From: Kostik Belousov <kostikbel@gmail.com> To: Jeff Roberson <jroberson@chesapeake.net> Cc: arch@freebsd.org Subject: Re: Changing p_swtime and td_slptime to ticks Message-ID: <20070918043335.GR79542@deviant.kiev.zoral.com.ua> In-Reply-To: <20070917165657.B558@10.0.0.1> References: <20070917165657.B558@10.0.0.1>
next in thread | previous in thread | raw e-mail | index | archive | help
--kAOhhqH5290wydqT Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Sep 17, 2007 at 05:05:57PM -0700, Jeff Roberson wrote: > Enclosed is a patch that fixes swapping with ULE. ULE has never properly= =20 > set p_swtime and td_slptime which are used by the swapout/swapin code to= =20 > select the appropriate thread to swap. >=20 > In 4BSD these two variables are increment once per-second as schedcpu()= =20 > iterates over all threads. ULE does not have a once per-second loop=20 > iterating over all threads. So I have changed p_swtime to p_swtick and= =20 > td_slptime to td_slptick. These record the value of 'ticks' when the=20 > thread slept or was last swapped in or out. >=20 > For backwards compatibility I leave the values in kinfo_proc with the=20 > legacy meaning by subtracting from ticks and dividing by hz. I perform a= =20 > similar transformation in the swapout code to convert to seconds. This= =20 > change does make it possible to use sub-second granular decisions in the= =20 > swap code, however I'm not sure if that's really necessary. >=20 > So that I did not disturb the 4BSD mechanism I kept the original=20 > td_slptime in the td_sched area. It should be possible to use td_slptick= =20 > directly but especially this close to release I did not want to change=20 > 4BSD. >=20 > Feedback and testing welcome. Purely cosmetic request: please make the ticks and hz variables in the libkvm/kvm_proc.c static. Or, even better, move it into the struct __kvm. --kAOhhqH5290wydqT Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.4 (FreeBSD) iD8DBQFG71UeC3+MBN1Mb4gRAhVLAJ4o2OWJfJJhUKRmIyGwrBArUvjO1wCguCF2 W1KjYYG1qcDbpc5l82GZBTE= =4GbX -----END PGP SIGNATURE----- --kAOhhqH5290wydqT--
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20070918043335.GR79542>