| 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: <xr9362vvwfr8.fsf@ninji.mtv.corp.google.com> Date: Wed, 17 Nov 2010 18:02:35 -0800 From: Greg Thelen <gthelen@...gle.com> To: Andrew Morton <akpm@...ux-foundation.org> Cc: linux-kernel@...r.kernel.org, linux-mm@...ck.org, containers@...ts.osdl.org, Andrea Righi <arighi@...eler.com>, Balbir Singh <balbir@...ux.vnet.ibm.com>, KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com>, Daisuke Nishimura <nishimura@....nes.nec.co.jp>, Minchan Kim <minchan.kim@...il.com>, Ciju Rajan K <ciju@...ux.vnet.ibm.com>, David Rientjes <rientjes@...gle.com>, Wu Fengguang <fengguang.wu@...el.com> Subject: Re: [PATCH v4 05/11] writeback: create dirty_info structure Andrew Morton <akpm@...ux-foundation.org> writes: > On Fri, 29 Oct 2010 00:09:08 -0700 > Greg Thelen <gthelen@...gle.com> wrote: > >> Bundle dirty limits and dirty memory usage metrics into a dirty_info >> structure to simplify interfaces of routines that need all. > > Problems... > > These patches interact pretty badly with Fengguang's "IO-less dirty > throttling v2" patches. I fixed up > writeback-create-dirty_info-structure.patch pretty mechanically but > when it got to memcg-check-memcg-dirty-limits-in-page-writeback.patch > things got sticky and I gave up. > > As your stuff was merged first, I'd normally send the bad news to > Fengguang, but the memcg code is logically built upon the core > writeback code so I do think these patches should be staged after the > changes to core writeback. > > Also, while I was there it seemed that the chosen members of the > dirty_info structure were a bit random. Perhaps we should be putting > nr_dirty in there as well, perhaps other things. Please have a think > about that. > > Also, in ratelimit_pages() we call global_dirty_info() to return four > items, but that caller only actually uses two of them. Wasted effort? > > > So I'm afraid I'm going to have to request that you redo and retest > these patches: > > writeback-create-dirty_info-structure.patch > memcg-add-dirty-page-accounting-infrastructure.patch > memcg-add-kernel-calls-for-memcg-dirty-page-stats.patch > memcg-add-dirty-limits-to-mem_cgroup.patch > memcg-add-dirty-limits-to-mem_cgroup-use-native-word-to-represent-dirtyable-pages.patch > memcg-add-dirty-limits-to-mem_cgroup-catch-negative-per-cpu-sums-in-dirty-info.patch > memcg-add-dirty-limits-to-mem_cgroup-avoid-overflow-in-memcg_hierarchical_free_pages.patch > memcg-add-dirty-limits-to-mem_cgroup-correct-memcg_hierarchical_free_pages-return-type.patch > memcg-add-dirty-limits-to-mem_cgroup-avoid-free-overflow-in-memcg_hierarchical_free_pages.patch > memcg-cpu-hotplug-lockdep-warning-fix.patch > memcg-add-cgroupfs-interface-to-memcg-dirty-limits.patch > memcg-break-out-event-counters-from-other-stats.patch > memcg-check-memcg-dirty-limits-in-page-writeback.patch > memcg-use-native-word-page-statistics-counters.patch > memcg-use-native-word-page-statistics-counters-fix.patch > # > memcg-add-mem_cgroup-parameter-to-mem_cgroup_page_stat.patch > memcg-pass-mem_cgroup-to-mem_cgroup_dirty_info.patch > #memcg-make-throttle_vm_writeout-memcg-aware.patch: "troublesome": Kamezawa > memcg-make-throttle_vm_writeout-memcg-aware.patch > memcg-make-throttle_vm_writeout-memcg-aware-fix.patch > memcg-simplify-mem_cgroup_page_stat.patch > memcg-simplify-mem_cgroup_dirty_info.patch > memcg-make-mem_cgroup_page_stat-return-value-unsigned.patch > > against the http://userweb.kernel.org/~akpm/mmotm/ which I just > uploaded, sorry. I've uploaded my copy of all the above to > http://userweb.kernel.org/~akpm/stuff/gthelen.tar.gz. I think only the > two patches need fixing and retesting. > > Also, while wrangling the above patches, I stumbled across rejects such > as: > > > *************** > *** 99,106 **** > "state: %8lx\n", > (unsigned long) K(bdi_stat(bdi, BDI_WRITEBACK)), > (unsigned long) K(bdi_stat(bdi, BDI_RECLAIMABLE)), > - K(bdi_thresh), K(dirty_thresh), > - K(background_thresh), nr_dirty, nr_io, nr_more_io, > !list_empty(&bdi->bdi_list), bdi->state); > #undef K > > --- 98,106 ---- > "state: %8lx\n", > (unsigned long) K(bdi_stat(bdi, BDI_WRITEBACK)), > (unsigned long) K(bdi_stat(bdi, BDI_RECLAIMABLE)), > + K(bdi_thresh), K(dirty_info.dirty_thresh), > + K(dirty_info.background_thresh), > + nr_dirty, nr_io, nr_more_io, > !list_empty(&bdi->bdi_list), bdi->state); > > Please, if you discover crud like this, just fix it up. One item per > line: > > "state: %8lx\n", > (unsigned long) K(bdi_stat(bdi, BDI_WRITEBACK)), > (unsigned long) K(bdi_stat(bdi, BDI_RECLAIMABLE)), > K(bdi_thresh), > K(dirty_info.dirty_thresh), > K(dirty_info.background_thresh), > nr_dirty, > nr_io, > nr_more_io, > !list_empty(&bdi->bdi_list), bdi->state); > > all very simple. And while you're there, fix up the > tab-tab-space-space-space indenting - just use tabs. > > > The other area where code maintenance is harder than it needs to be is > in definitions of locals: > > long nr_reclaimable; > long nr_dirty, bdi_dirty; /* = file_dirty + writeback + unstable_nfs */ > long bdi_prev_dirty = 0; > > again, that's just dopey. Change it to > > long nr_reclaimable; > long nr_dirty; > long bdi_dirty; /* = file_dirty + writeback + unstable_nfs */ > long bdi_prev_dirty = 0; > > All very simple. > > Thanks. I am leaving on vacation until Mon. Once I return, this will be one of the first things I get to. I will resubmit patches based on whatever the latest mmotm on Mon. -- 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