lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Mon, 11 Jun 2007 19:08:06 -0700 From: "Siddha, Suresh B" <suresh.b.siddha@...el.com> To: Arjan van de Ven <arjan@...ux.intel.com> Cc: Andrew Morton <akpm@...ux-foundation.org>, "Keshavamurthy, Anil S" <anil.s.keshavamurthy@...el.com>, Andi Kleen <ak@...e.de>, Christoph Lameter <clameter@....com>, linux-kernel@...r.kernel.org, gregkh@...e.de, muli@...ibm.com, asit.k.mallick@...el.com, suresh.b.siddha@...el.com, ashok.raj@...el.com, shaohua.li@...el.com, davem@...emloft.net Subject: Re: [Intel-IOMMU 02/10] Library routine for pre-allocat pool handling On Mon, Jun 11, 2007 at 06:55:46PM -0700, Arjan van de Ven wrote: > Andrew Morton wrote: > >On Mon, 11 Jun 2007 18:10:40 -0700 Arjan van de Ven > ><arjan@...ux.intel.com> wrote: > > > >>Andrew Morton wrote: > >>>>Where as resource pool is exactly opposite of mempool, where each > >>>>time it looks for an object in the pool and if it exist then we > >>>>return that object else we try to get the memory for OS while > >>>>scheduling the work to grow the pool objects. In fact, the work > >>>>is schedule to grow the pool when the low threshold point is hit. > >>>I realise all that. But I'd have thought that the mempool approach is > >>>actually better: use the page allocator and only deplete your reserve > >>>pool > >>>when the page allocator fails. > >>the problem with that is that if anything downstream from the iommu > >>layer ALSO needs memory, we've now eaten up the last free page and > >>things go splat. > > > >If that happens, we still have the mempool reserve to fall back to. > > we do, except that we just ate the memory the downstream code would > use and get ... so THAT can't get any. Then this problem can happen, irrespective of the changes we are reviewing in this patch set. Is n't it? thanks, suresh - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists