Date: Fri, 4 Jan 2008 16:18:57 +0200 From: Kostik Belousov <kostikbel@gmail.com> To: Skip Ford <skip@menantico.com> Cc: Dag-Erling =?koi8-r?B?U23DuHJncmF2?= <des@des.no>, freebsd-current@FreeBSD.org, Robert Watson <rwatson@FreeBSD.org>, Jason Evans <jasone@FreeBSD.org>, Poul-Henning Kamp <phk@FreeBSD.org> Subject: Re: sbrk(2) broken Message-ID: <20080104141857.GC57756@deviant.kiev.zoral.com.ua> In-Reply-To: <20080104141133.GB788@menantico.com> References: <477C82F0.5060809@freebsd.org> <863ateemw2.fsf@ds4.des.no> <20080104002002.L30578@fledge.watson.org> <86wsqqaqbe.fsf@ds4.des.no> <20080104110511.S77222@fledge.watson.org> <20080104135438.GA788@menantico.com> <20080104135912.GB57756@deviant.kiev.zoral.com.ua> <20080104141133.GB788@menantico.com>
next in thread | previous in thread | raw e-mail | index | archive | help
--h8+hH1OQkST14sOt Content-Type: text/plain; charset=koi8-r Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Jan 04, 2008 at 09:11:33AM -0500, Skip Ford wrote: > Kostik Belousov wrote: > > On Fri, Jan 04, 2008 at 08:54:38AM -0500, Skip Ford wrote: > > > Robert Watson wrote: > > > > On Fri, 4 Jan 2008, Dag-Erling Sm=F8rgrav wrote: > > > > >Robert Watson <rwatson@FreeBSD.org> writes: > > > > >>The right answer is presumably to introduce a new LIMIT_SWAP, whi= ch > > > > >>limits the allocation of anonymous memory by processes, and size = it to > > > > >>something like 90% of swap space by default. > > > > > > > > > >Not a good solution on its own. You need a per-process limit as w= ell,=20 > > > > >otherwise a malloc() bomb will still cause other processes to fail= =20 > > > > >randomly. > > > >=20 > > > > That was what I had in mind, the above should read RLIMIT_SWAP. > > >=20 > > > Are you referring to the implementation of RLIMIT_SWAP in the > > > overcommit-disable patch at: > > >=20 > > > http://people.freebsd.org/~kib/overcommit/index.html > > >=20 > > > ...or some other as yet unwritten implementation? That patch doesn't > > > currently do 90% of swap but easily can. That's been available for a= lmost 3 > > > years now. I tested it at one point but not lately and it never went= into > > > production. Do you, and others, have a problem with that implementat= ion? > > Oh, I thought that I was the sole user of the patch. What problems did = you > > encountered while testing it ? >=20 > Nope, there are two of us. :-) >=20 > I don't remember encountering problems. I never put it into production > because maintaining it in a local branch was beyond my ability. I just d= idn't > know enough to know what it did and didn't do, or how it would have to be > modified to work with future changes. I just didn't understand it enough > to go with it and maintain it. >=20 > > What you mean by "do 90% of swap" ? >=20 > I was referring only to what Robert said above, that he thinks RLIMIT_SWAP > should limit anon memory size to ~90% of swap by default. Your patch, > last I looked, limits it to 100% of swap by design but could be easily > changed I think. Ok. The patch really imposes two kind of limits: - the total amount of anon memory that could be allocated in the whole system (this is what I called "disabling overcommit") - per-user RLIMIT_SWAP limit, that account the allocation by the uid. This has some obvious problems with setuid(2) syscall. AFAIR, I ended up not moving the accounted numbers to the new uid. Both limits can be turned on/off independently. May be, time to revive it. --h8+hH1OQkST14sOt Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.7 (FreeBSD) iD8DBQFHfkBRC3+MBN1Mb4gRAuIKAKCqu7wKHFsS4zsrOKezEd6DeYQ0mgCfRwAV UjCx3JJfxU6zL01EJ5Iq4/s= =tHbx -----END PGP SIGNATURE----- --h8+hH1OQkST14sOt--
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20080104141857.GC57756>