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
| ||
|
Message-ID: <1411025936.13381.183.camel@haakon3.risingtidesystems.com> Date: Thu, 18 Sep 2014 00:38:56 -0700 From: "Nicholas A. Bellinger" <nab@...ux-iscsi.org> To: Christoph Hellwig <hch@....de> Cc: Andy Grover <agrover@...hat.com>, target-devel@...r.kernel.org, linux-scsi@...r.kernel.org, linux-kernel@...r.kernel.org, Linus Torvalds <torvalds@...ux-foundation.org> Subject: Re: [PATCHv3 0/8] target: Save memory on unused se_dev_entrys and se_luns On Sat, 2014-09-13 at 21:55 +0200, Christoph Hellwig wrote: > On Tue, Jul 29, 2014 at 03:15:11PM +0200, Christoph Hellwig wrote: > > Nic, > > > > any progress on looking over these? Seems like there's actually > > nothing at all queued up for 3.17 in the target tree, or am І missing > > something? > > ping again. We're getting closer to the end of the 3.18 merge window > and there still hasn't been a response. Should Andy just send the patches > directly to Linus once 3.18 opens given that they have been out on the list > since Jun 23? (with a positive review from me and no negative one) > Removing unused per WWPN endpoint LUN + per NodeACL MappedLUN memory is a nice optimization to have, but I'm not yet convinced that extending existing control path spinlocks to support an array of pointers is ultimately worth the complexity it adds here. Another concern is how these changes effect active session + device I/O shutdown, which is an area of regressions I'd rather avoid if the primary benefit of this series is only reducing memory footprint for unused LUNs + MappedLUNs. Lowering the TRANSPORT_MAX_LUNS_PER_TPG value at compile time today is the simple way for reducing overall memory footprint for folks who need to scale up the number of targets using smaller individual LUN mappings. As for something smarter, given the mostly read-only nature of LUN + MappedLUN pointers to individual TPGT + NodeACLs context, I'd rather see something based on RCU arrays + percpu_ref counting to avoid this type of complexity to existing code, and move in the direction of dropping fast-path I_T ->device_list_lock access all together. Beyond these objections, there are some useful fixes + cleanups from this series that I'm OK with merging soon.. --nab -- 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