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* include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo2010-03-3027-10/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
* Merge branch 'core-fixes-for-linus' of ↵Linus Torvalds2010-03-261-13/+0
|\ | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86: Remove excessive early_res debug output softlockup: Stop spurious softlockup messages due to overflow rcu: Fix local_irq_disable() CONFIG_PROVE_RCU=y false positives rcu: Fix tracepoints & lockdep false positive rcu: Make rcu_read_lock_bh_held() allow for disabled BH
| * x86: Remove excessive early_res debug outputJiri Kosina2010-03-241-13/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 08677214e318297 ("x86: Make 64 bit use early_res instead of bootmem before slab") introduced early_res replacement for bootmem, but left code in __free_pages_memory() which dumps all the ranges that are beeing freed, without any additional information, causing some noise in dmesg during bootup. Just remove printing of the ranges, that doesn't provide anything useful anyway. While at it, remove other commented-out KERN_DEBUG messages in the NO_BOOTMEM code as well. Signed-off-by: Jiri Kosina <jkosina@suse.cz> Found-OK-by: Andrew Morton <akpm@linux-foundation.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Yinghai Lu <yinghai@kernel.org> LKML-Reference: <alpine.LNX.2.00.1003220931360.18642@pobox.suse.cz> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | NOMMU: Fix __get_user_pages() to pin last page on offset buffersDavid Howells2010-03-251-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix __get_user_pages() to make it pin the last page on a buffer that doesn't begin at the start of a page, but is a multiple of PAGE_SIZE in size. The problem is that __get_user_pages() advances the pointer too much when it iterates to the next page if the page it's currently looking at isn't used from the first byte. This can cause the end of a short VMA to be reached prematurely, resulting in the last page being lost. Signed-off-by: Steven J. Magnani <steve@digidescorp.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | NOMMU: Revert 'nommu: get_user_pages(): pin last page on non-page-aligned start'David Howells2010-03-251-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Revert the following patch: commit c08c6e1f54c85fc299cf9f88cf330d6dd28a9a1d Author: Steven J. Magnani <steve@digidescorp.com> Date: Fri Mar 5 13:42:24 2010 -0800 nommu: get_user_pages(): pin last page on non-page-aligned start As it assumes that the mappings begin at the start of pages - something that isn't necessarily true on NOMMU systems. On NOMMU systems, it is possible for a mapping to only occupy part of the page, and not necessarily touch either end of it; in fact it's also possible for multiple non-overlapping mappings to coexist on one page (consider direct mappings of ROMFS files, for example). Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Steven J. Magnani <steve@digidescorp.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mempolicy: fix get_mempolicy() for relative and static nodesLee Schermerhorn2010-03-241-3/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Discovered while testing other mempolicy changes: get_mempolicy() does not handle static/relative mode flags correctly. Return the value that the user specified so that it can be restored via set_mempolicy() if desired. Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk> Cc: Ravikiran Thirumalai <kiran@scalex86.org> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | exit: fix oops in sync_mm_rssMichael S. Tsirkin2010-03-242-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In 2.6.34-rc1, removing vhost_net module causes an oops in sync_mm_rss (called from do_exit) when workqueue is destroyed. This does not happen on net-next, or with vhost on top of to 2.6.33. The issue seems to be introduced by 34e55232e59f7b19050267a05ff1226e5cd122a5 ("mm: avoid false sharing of mm_counter) which added sync_mm_rss() that is passed task->mm, and dereferences it without checking. If task is a kernel thread, mm might be NULL. I think this might also happen e.g. with aio. This patch fixes the oops by calling sync_mm_rss when task->mm is set to NULL. I also added BUG_ON to detect any other cases where counters get incremented while mm is NULL. The oops I observed looks like this: BUG: unable to handle kernel NULL pointer dereference at 00000000000002a8 IP: [<ffffffff810b436d>] sync_mm_rss+0x33/0x6f PGD 0 Oops: 0002 [#1] SMP last sysfs file: /sys/devices/system/cpu/cpu7/cache/index2/shared_cpu_map CPU 2 Modules linked in: vhost_net(-) tun bridge stp sunrpc ipv6 cpufreq_ondemand acpi_cpufreq freq_table kvm_intel kvm i5000_edac edac_core rtc_cmos bnx2 button i2c_i801 i2c_core rtc_core e1000e sg joydev ide_cd_mod serio_raw pcspkr rtc_lib cdrom virtio_net virtio_blk virtio_pci virtio_ring virtio af_packet e1000 shpchp aacraid uhci_hcd ohci_hcd ehci_hcd [last unloaded: microcode] Pid: 2046, comm: vhost Not tainted 2.6.34-rc1-vhost #25 System Planar/IBM System x3550 -[7978B3G]- RIP: 0010:[<ffffffff810b436d>] [<ffffffff810b436d>] sync_mm_rss+0x33/0x6f RSP: 0018:ffff8802379b7e60 EFLAGS: 00010202 RAX: 0000000000000008 RBX: ffff88023f2390c0 RCX: 0000000000000000 RDX: ffff88023f2396b0 RSI: 0000000000000000 RDI: ffff88023f2390c0 RBP: ffff8802379b7e60 R08: 0000000000000000 R09: 0000000000000000 R10: ffff88023aecfbc0 R11: 0000000000013240 R12: 0000000000000000 R13: ffffffff81051a6c R14: ffffe8ffffc0f540 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff880001e80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 00000000000002a8 CR3: 000000023af23000 CR4: 00000000000406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process vhost (pid: 2046, threadinfo ffff8802379b6000, task ffff88023f2390c0) Stack: ffff8802379b7ee0 ffffffff81040687 ffffe8ffffc0f558 ffffffffa00a3e2d <0> 0000000000000000 ffff88023f2390c0 ffffffff81055817 ffff8802379b7e98 <0> ffff8802379b7e98 0000000100000286 ffff8802379b7ee0 ffff88023ad47d78 Call Trace: [<ffffffff81040687>] do_exit+0x147/0x6c4 [<ffffffffa00a3e2d>] ? handle_rx_net+0x0/0x17 [vhost_net] [<ffffffff81055817>] ? autoremove_wake_function+0x0/0x39 [<ffffffff81051a6c>] ? worker_thread+0x0/0x229 [<ffffffff810553c9>] kthreadd+0x0/0xf2 [<ffffffff810038d4>] kernel_thread_helper+0x4/0x10 [<ffffffff81055342>] ? kthread+0x0/0x87 [<ffffffff810038d0>] ? kernel_thread_helper+0x0/0x10 Code: 00 8b 87 6c 02 00 00 85 c0 74 14 48 98 f0 48 01 86 a0 02 00 00 c7 87 6c 02 00 00 00 00 00 00 8b 87 70 02 00 00 85 c0 74 14 48 98 <f0> 48 01 86 a8 02 00 00 c7 87 70 02 00 00 00 00 00 00 8b 87 74 RIP [<ffffffff810b436d>] sync_mm_rss+0x33/0x6f RSP <ffff8802379b7e60> CR2: 00000000000002a8 ---[ end trace 41603ba922beddd2 ]--- Fixing recursive fault but reboot is needed! (note: handle_rx_net is a work item using workqueue in question). sync_mm_rss+0x33/0x6f gave me a hint. I also tried reverting 34e55232e59f7b19050267a05ff1226e5cd122a5 and the oops goes away. The module in question calls use_mm and later unuse_mm from a kernel thread. It is when this kernel thread is destroyed that the crash happens. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Andrea Arcangeli <aarcange@redhat.com> Reviewed-by: Rik van Riel <riel@redhat.com> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | tmpfs: cleanup mpol_parse_str()KOSAKI Motohiro2010-03-241-12/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | mpol_parse_str() made lots 'err' variable related bug. Because it is ugly and reviewing unfriendly. This patch simplifies it. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Ravikiran Thirumalai <kiran@scalex86.org> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Mel Gorman <mel@csn.ul.ie> Acked-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | tmpfs: handle MPOL_LOCAL mount option properlyKOSAKI Motohiro2010-03-241-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 71fe804b6d5 (mempolicy: use struct mempolicy pointer in shmem_sb_info) added mpol=local mount option. but its feature is broken since it was born. because such code always return 1 (i.e. mount failure). This patch fixes it. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Ravikiran Thirumalai <kiran@scalex86.org> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Mel Gorman <mel@csn.ul.ie> Acked-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | tmpfs: mpol=bind:0 don't cause mount error.KOSAKI Motohiro2010-03-241-3/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, following mount operation cause mount error. % mount -t tmpfs -ompol=bind:0 none /tmp Because commit 71fe804b6d5 (mempolicy: use struct mempolicy pointer in shmem_sb_info) corrupted MPOL_BIND parse code. This patch restore the needed one. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Ravikiran Thirumalai <kiran@scalex86.org> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Mel Gorman <mel@csn.ul.ie> Acked-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | tmpfs: fix oops on mounts with mpol=defaultRavikiran G Thirumalai2010-03-241-2/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix an 'oops' when a tmpfs mount point is mounted with the mpol=default mempolicy. Upon remounting a tmpfs mount point with 'mpol=default' option, the mount code crashed with a null pointer dereference. The initial problem report was on 2.6.27, but the problem exists in mainline 2.6.34-rc as well. On examining the code, we see that mpol_new returns NULL if default mempolicy was requested. This 'NULL' mempolicy is accessed to store the node mask resulting in oops. The following patch fixes it. Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org> Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Mel Gorman <mel@csn.ul.ie> Acked-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm/ksm.c is doing an unneeded _notify in write_protect_page.Robin Holt2010-03-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ksm.c's write_protect_page implements a lockless means of verifying a page does not have any users of the page which are not accounted for via other kernel tracking means. It does this by removing the writable pte with TLB flushes, checking the page_count against the total known users, and then using set_pte_at_notify to make it a read-only entry. An unneeded mmu_notifier callout is made in the case where the known users does not match the page_count. In that event, we are inserting the identical pte and there is no need for the set_pte_at_notify, but rather the simpler set_pte_at suffices. Signed-off-by: Robin Holt <holt@sgi.com> Acked-by: Izik Eidus <ieidus@redhat.com> Acked-by: Andrea Arcangeli <aarcange@redhat.com> Acked-by: Hugh Dickins <hugh.dickins@tiscali.co.uk> Cc: Chris Wright <chrisw@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | nommu: fix an incorrect comment in the do_mmap_shared_file()David Howells2010-03-241-4/+3
| | | | | | | | | | | | | | | | | | | | | | Fix an incorrect comment in the do_mmap_shared_file(). If a mapping is requested MAP_SHARED, then a private copy cannot be made and still provide correct semantics. Signed-off-by: David Howells <dhowells@redhat.com> Reported-by: Dave Hudson <uclinux@blueteddy.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | memcontrol: fix potential null derefDan Carpenter2010-03-241-2/+4
| | | | | | | | | | | | | | | | | | | | There was a potential null deref introduced in c62b1a3b31b5 ("memcg: use generic percpu instead of private implementation"). Signed-off-by: Dan Carpenter <error27@gmail.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | memcg: disable move charge in no mmu caseDaisuke Nishimura2010-03-241-22/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In commit 02491447 ("memcg: move charges of anonymous swap"), I tried to disable move charge feature in no mmu case by enclosing all the related functions with "#ifdef CONFIG_MMU", but the commit places these ifdefs in wrong place. (it seems that it's mangled while handling some fixes...) This patch fixes it up. Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@in.ibm.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | memcg: avoid use cmpxchg in swap cgroup maintainanceKAMEZAWA Hiroyuki2010-03-171-4/+16
|/ | | | | | | | | | | | | | | swap_cgroup uses 2bytes data and uses cmpxchg in a new operation. 2byte cmpxchg/xchg is not available on some archs. This patch replaces cmpxchg/xchg with operations under lock. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reported-by: Sachin Sant <sachinp@in.ibm.com> wrote: Acked-by: Balbir Singh <balbir@in.ibm.com> Acked-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'core-fixes-for-linus' of ↵Linus Torvalds2010-03-131-0/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: locking: Make sparse work with inline spinlocks and rwlocks x86/mce: Fix RCU lockdep splats rcu: Increase RCU CPU stall timeouts if PROVE_RCU ftrace: Replace read_barrier_depends() with rcu_dereference_raw() rcu: Suppress RCU lockdep warnings during early boot rcu, ftrace: Fix RCU lockdep splat in ftrace_perf_buf_prepare() rcu: Suppress __mpol_dup() false positive from RCU lockdep rcu: Make rcu_read_lock_sched_held() handle !PREEMPT rcu: Add control variables to lockdep_rcu_dereference() diagnostics rcu, cgroup: Relax the check in task_subsys_state() as early boot is now handled by lockdep-RCU rcu: Use wrapper function instead of exporting tasklist_lock sched, rcu: Fix rcu_dereference() for RCU-lockdep rcu: Make task_subsys_state() RCU-lockdep checks handle boot-time use rcu: Fix holdoff for accelerated GPs for last non-dynticked CPU x86/gart: Unexport gart_iommu_aperture Fix trivial conflicts in kernel/trace/ftrace.c
| * rcu: Suppress __mpol_dup() false positive from RCU lockdepPaul E. McKenney2010-03-041-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Common code is used during task creation and after the task has started running. RCU protection is not needed during task creation because no other CPU has access to the under-construction task. Provide the RCU protection anyway to suppress the false positive, as there does not appear to be a good way for the common code to recognize that the task is only accessible to the CPU creating it. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Menage <menage@google.com> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: dhowells@redhat.com LKML-Reference: <1267667418-32233-2-git-send-email-paulmck@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | Merge branch 'for-linus' of ↵Linus Torvalds2010-03-122-2/+2
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (56 commits) doc: fix typo in comment explaining rb_tree usage Remove fs/ntfs/ChangeLog doc: fix console doc typo doc: cpuset: Update the cpuset flag file Fix of spelling in arch/sparc/kernel/leon_kernel.c no longer needed Remove drivers/parport/ChangeLog Remove drivers/char/ChangeLog doc: typo - Table 1-2 should refer to "status", not "statm" tree-wide: fix typos "ass?o[sc]iac?te" -> "associate" in comments No need to patch AMD-provided drivers/gpu/drm/radeon/atombios.h devres/irq: Fix devm_irq_match comment Remove reference to kthread_create_on_cpu tree-wide: Assorted spelling fixes tree-wide: fix 'lenght' typo in comments and code drm/kms: fix spelling in error message doc: capitalization and other minor fixes in pnp doc devres: typo fix s/dev/devm/ Remove redundant trailing semicolons from macros fix typo "definetly" -> "definitely" in comment tree-wide: s/widht/width/g typo in comments ... Fix trivial conflict in Documentation/laptops/00-INDEX
| * \ Merge branch 'for-next' into for-linusJiri Kosina2010-03-082-2/+2
| |\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: Documentation/filesystems/proc.txt arch/arm/mach-u300/include/mach/debug-macro.S drivers/net/qlge/qlge_ethtool.c drivers/net/qlge/qlge_main.c drivers/net/typhoon.c
| | * | grammar fix in commentUwe Kleine-König2010-02-051-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Cc: Nicolas Pitre <nico@marvell.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
| | * | Fix misspelling of "should" and "shouldn't" in comments.Adam Buchbinder2010-02-051-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Some comments misspell "should" or "shouldn't"; this fixes them. No code changes. Signed-off-by: Adam Buchbinder <adam.buchbinder@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* | | | memcg: fix oom kill behaviorKAMEZAWA Hiroyuki2010-03-122-35/+107
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In current page-fault code, handle_mm_fault() -> ... -> mem_cgroup_charge() -> map page or handle error. -> check return code. If page fault's return code is VM_FAULT_OOM, page_fault_out_of_memory() is called. But if it's caused by memcg, OOM should have been already invoked. Then, I added a patch: a636b327f731143ccc544b966cfd8de6cb6d72c6. That patch records last_oom_jiffies for memcg's sub-hierarchy and prevents page_fault_out_of_memory from being invoked in near future. But Nishimura-san reported that check by jiffies is not enough when the system is terribly heavy. This patch changes memcg's oom logic as. * If memcg causes OOM-kill, continue to retry. * remove jiffies check which is used now. * add memcg-oom-lock which works like perzone oom lock. * If current is killed(as a process), bypass charge. Something more sophisticated can be added but this pactch does fundamental things. TODO: - add oom notifier - add permemcg disable-oom-kill flag and freezer at oom. - more chances for wake up oom waiter (when changing memory limit etc..) Reviewed-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Tested-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | cgroups: remove events before destroying subsystem state objectsKirill A. Shutemov2010-03-121-9/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Events should be removed after rmdir of cgroup directory, but before destroying subsystem state objects. Let's take reference to cgroup directory dentry to do that. Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hioryu@jp.fujitsu.com> Cc: Paul Menage <menage@google.com> Acked-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Dan Malek <dan@embeddedalley.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | memcg: handle panic_on_oom=always caseKAMEZAWA Hiroyuki2010-03-121-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Presently, if panic_on_oom=2, the whole system panics even if the oom happend in some special situation (as cpuset, mempolicy....). Then, panic_on_oom=2 means painc_on_oom_always. Now, memcg doesn't check panic_on_oom flag. This patch adds a check. BTW, how it's useful ? kdump+panic_on_oom=2 is the last tool to investigate what happens in oom-ed system. When a task is killed, the sysytem recovers and there will be few hint to know what happnes. In mission critical system, oom should never happen. Then, panic_on_oom=2+kdump is useful to avoid next OOM by knowing precise information via snapshot. TODO: - For memcg, it's for isolate system's memory usage, oom-notiifer and freeze_at_oom (or rest_at_oom) should be implemented. Then, management daemon can do similar jobs (as kdump) or taking snapshot per cgroup. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: David Rientjes <rientjes@google.com> Cc: Nick Piggin <npiggin@suse.de> Reviewed-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | memcg : share event counter rather than duplicateKAMEZAWA Hiroyuki2010-03-121-45/+41
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Memcg has 2 eventcountes which counts "the same" event. Just usages are different from each other. This patch tries to reduce event counter. Now logic uses "only increment, no reset" counter and masks for each checks. Softlimit chesk was done per 1000 evetns. So, the similar check can be done by !(new_counter & 0x3ff). Threshold check was done per 100 events. So, the similar check can be done by (!new_counter & 0x7f) ALL event checks are done right after EVENT percpu counter is updated. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Kirill A. Shutemov <kirill@shutemov.name> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | memcg: update threshold and softlimit at commitKAMEZAWA Hiroyuki2010-03-121-20/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Presently, move_task does "batched" precharge. Because res_counter or css's refcnt are not-scalable jobs for memcg, try_charge_().. tend to be done in batched manner if allowed. Now, softlimit and threshold check their event counter in try_charge, but the charge is not a per-page event. And event counter is not updated at charge(). Moreover, precharge doesn't pass "page" to try_charge() and softlimit tree will be never updated until uncharge() causes an event." So the best place to check the event counter is commit_charge(). This is per-page event by its nature. This patch move checks to there. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Kirill A. Shutemov <kirill@shutemov.name> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | memcg: use generic percpu instead of private implementationKAMEZAWA Hiroyuki2010-03-121-121/+63
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When per-cpu counter for memcg was implemneted, dynamic percpu allocator was not very good. But now, we have good one and useful macros. This patch replaces memcg's private percpu counter implementation with generic dynamic percpu allocator. The benefits are - We can remove private implementation. - The counters will be NUMA-aware. (Current one is not...) - This patch makes sizeof struct mem_cgroup smaller. Then, struct mem_cgroup may be fit in page size on small config. - About basic performance aspects, see below. [Before] # size mm/memcontrol.o text data bss dec hex filename 24373 2528 4132 31033 7939 mm/memcontrol.o [page-fault-throuput test on 8cpu/SMP in root cgroup] # /root/bin/perf stat -a -e page-faults,cache-misses --repeat 5 ./multi-fault-fork 8 Performance counter stats for './multi-fault-fork 8' (5 runs): 45878618 page-faults ( +- 0.110% ) 602635826 cache-misses ( +- 0.105% ) 61.005373262 seconds time elapsed ( +- 0.004% ) Then cache-miss/page fault = 13.14 [After] #size mm/memcontrol.o text data bss dec hex filename 23913 2528 4132 30573 776d mm/memcontrol.o # /root/bin/perf stat -a -e page-faults,cache-misses --repeat 5 ./multi-fault-fork 8 Performance counter stats for './multi-fault-fork 8' (5 runs): 48179400 page-faults ( +- 0.271% ) 588628407 cache-misses ( +- 0.136% ) 61.004615021 seconds time elapsed ( +- 0.004% ) Then cache-miss/page fault = 12.22 Text size is reduced. This performance improvement is not big and will be invisible in real world applications. But this result shows this patch has some good effect even on (small) SMP. Here is a test program I used. 1. fork() processes on each cpus. 2. do page fault repeatedly on each process. 3. after 60secs, kill all childredn and exit. (3 is necessary for getting stable data, this is improvement from previous one.) #define _GNU_SOURCE #include <stdio.h> #include <sched.h> #include <sys/mman.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <signal.h> #include <stdlib.h> /* * For avoiding contention in page table lock, FAULT area is * sparse. If FAULT_LENGTH is too large for your cpus, decrease it. */ #define FAULT_LENGTH (2 * 1024 * 1024) #define PAGE_SIZE 4096 #define MAXNUM (128) void alarm_handler(int sig) { } void *worker(int cpu, int ppid) { void *start, *end; char *c; cpu_set_t set; int i; CPU_ZERO(&set); CPU_SET(cpu, &set); sched_setaffinity(0, sizeof(set), &set); start = mmap(NULL, FAULT_LENGTH, PROT_READ|PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, 0, 0); if (start == MAP_FAILED) { perror("mmap"); exit(1); } end = start + FAULT_LENGTH; pause(); //fprintf(stderr, "run%d", cpu); while (1) { for (c = (char*)start; (void *)c < end; c += PAGE_SIZE) *c = 0; madvise(start, FAULT_LENGTH, MADV_DONTNEED); } return NULL; } int main(int argc, char *argv[]) { int num, i, ret, pid, status; int pids[MAXNUM]; if (argc < 2) return 0; setpgid(0, 0); signal(SIGALRM, alarm_handler); num = atoi(argv[1]); pid = getpid(); for (i = 0; i < num; ++i) { ret = fork(); if (!ret) { worker(i, pid); exit(0); } pids[i] = ret; } sleep(1); kill(-pid, SIGALRM); sleep(60); for (i = 0; i < num; i++) kill(pids[i], SIGKILL); for (i = 0; i < num; i++) waitpid(pids[i], &status, 0); return 0; } Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | memcg: typo in comment to mem_cgroup_print_oom_info()Kirill A. Shutemov2010-03-121-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | s/mem_cgroup_print_mem_info/mem_cgroup_print_oom_info/ Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | memcg: implement memory thresholdsKirill A. Shutemov2010-03-121-0/+309
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It allows to register multiple memory and memsw thresholds and gets notifications when it crosses. To register a threshold application need: - create an eventfd; - open memory.usage_in_bytes or memory.memsw.usage_in_bytes; - write string like "<event_fd> <memory.usage_in_bytes> <threshold>" to cgroup.event_control. Application will be notified through eventfd when memory usage crosses threshold in any direction. It's applicable for root and non-root cgroup. It uses stats to track memory usage, simmilar to soft limits. It checks if we need to send event to userspace on every 100 page in/out. I guess it's good compromise between performance and accuracy of thresholds. [akpm@linux-foundation.org: coding-style fixes] [nishimura@mxp.nes.nec.co.jp: fix documentation merge issue] Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Dan Malek <dan@embeddedalley.com> Cc: Vladislav Buzov <vbuzov@embeddedalley.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Alexander Shishkin <virtuoso@slind.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | memcg: rework usage of stats by soft limitKirill A. Shutemov2010-03-121-8/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of incrementing counter on each page in/out and comparing it with constant, we set counter to constant, decrement counter on each page in/out and compare it with zero. We want to make comparing as fast as possible. On many RISC systems (probably not only RISC) comparing with zero is more effective than comparing with a constant, since not every constant can be immediate operand for compare instruction. Also, I've renamed MEM_CGROUP_STAT_EVENTS to MEM_CGROUP_STAT_SOFTLIMIT, since really it's not a generic counter. Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Dan Malek <dan@embeddedalley.com> Cc: Vladislav Buzov <vbuzov@embeddedalley.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Alexander Shishkin <virtuoso@slind.org> Cc: Davide Libenzi <davidel@xmailserver.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | memcg: extract mem_group_usage() from mem_cgroup_read()Kirill A. Shutemov2010-03-121-22/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Helper to get memory or mem+swap usage of the cgroup. Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Dan Malek <dan@embeddedalley.com> Cc: Vladislav Buzov <vbuzov@embeddedalley.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Alexander Shishkin <virtuoso@slind.org> Cc: Davide Libenzi <davidel@xmailserver.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | memcg: improve performance in moving swap chargeDaisuke Nishimura2010-03-121-15/+60
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Try to reduce overheads in moving swap charge by: - Adds a new function(__mem_cgroup_put), which takes "count" as a arg and decrement mem->refcnt by "count". - Removed res_counter_uncharge, css_put, and mem_cgroup_put from the path of moving swap account, and consolidate all of them into mem_cgroup_clear_mc. We cannot do that about mc.to->refcnt. These changes reduces the overhead from 1.35sec to 0.9sec to move charges of 1G anonymous memory(including 500MB swap) in my test environment. Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | memcg: move charges of anonymous swapDaisuke Nishimura2010-03-123-38/+210
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch is another core part of this move-charge-at-task-migration feature. It enables moving charges of anonymous swaps. To move the charge of swap, we need to exchange swap_cgroup's record. In current implementation, swap_cgroup's record is protected by: - page lock: if the entry is on swap cache. - swap_lock: if the entry is not on swap cache. This works well in usual swap-in/out activity. But this behavior make the feature of moving swap charge check many conditions to exchange swap_cgroup's record safely. So I changed modification of swap_cgroup's recored(swap_cgroup_record()) to use xchg, and define a new function to cmpxchg swap_cgroup's record. This patch also enables moving charge of non pte_present but not uncharged swap caches, which can be exist on swap-out path, by getting the target pages via find_get_page() as do_mincore() does. [kosaki.motohiro@jp.fujitsu.com: fix ia64 build] [akpm@linux-foundation.org: fix typos] Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | memcg: avoid oom during moving chargeDaisuke Nishimura2010-03-121-2/+51
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This move-charge-at-task-migration feature has extra charges on "to"(pre-charges) and "from"(left-over charges) during moving charge. This means unnecessary oom can happen. This patch tries to avoid such oom. Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | memcg: improve performance in moving chargeDaisuke Nishimura2010-03-121-54/+98
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Try to reduce overheads in moving charge by: - Instead of calling res_counter_uncharge() against the old cgroup in __mem_cgroup_move_account() everytime, call res_counter_uncharge() at the end of task migration once. - removed css_get(&to->css) from __mem_cgroup_move_account() because callers should have already called css_get(). And removed css_put(&to->css) too, which was called by callers of move_account on success of move_account. - Instead of calling __mem_cgroup_try_charge(), i.e. res_counter_charge(), repeatedly, call res_counter_charge(PAGE_SIZE * count) in can_attach() if possible. - Instead of calling css_get()/css_put() repeatedly, make use of coalesce __css_get()/__css_put() if possible. These changes reduces the overhead from 1.7sec to 0.6sec to move charges of 1G anonymous memory in my test environment. Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | memcg: move charges of anonymous pageDaisuke Nishimura2010-03-121-10/+284
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch is the core part of this move-charge-at-task-migration feature. It implements functions to move charges of anonymous pages mapped only by the target task. Implementation: - define struct move_charge_struct and a valuable of it(mc) to remember the count of pre-charges and other information. - At can_attach(), get anon_rss of the target mm, call __mem_cgroup_try_charge() repeatedly and count up mc.precharge. - At attach(), parse the page table, find a target page to be move, and call mem_cgroup_move_account() about the page. - Cancel all precharges if mc.precharge > 0 on failure or at the end of task move. [akpm@linux-foundation.org: a little simplification] Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | memcg: add interface to move charge at task migrationDaisuke Nishimura2010-03-121-4/+93
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In current memcg, charges associated with a task aren't moved to the new cgroup at task migration. Some users feel this behavior to be strange. These patches are for this feature, that is, for charging to the new cgroup and, of course, uncharging from the old cgroup at task migration. This patch adds "memory.move_charge_at_immigrate" file, which is a flag file to determine whether charges should be moved to the new cgroup at task migration or not and what type of charges should be moved. This patch also adds read and write handlers of the file. This patch also adds no-op handlers for this feature. These handlers will be implemented in later patches. And you cannot write any values other than 0 to move_charge_at_immigrate yet. Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | Add generic sys_old_mmap()Christoph Hellwig2010-03-122-0/+48
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a generic implementation of the old mmap() syscall, which expects its argument in a memory block and switch all architectures over to use it. Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Jeff Dike <jdike@addtoit.com> Cc: Hirokazu Takata <takata@linux-m32r.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Reviewed-by: H. Peter Anvin <hpa@zytor.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: James Morris <jmorris@namei.org> Cc: Andreas Schwab <schwab@linux-m68k.org> Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> Acked-by: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Greg Ungerer <gerg@uclinux.org> Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | mm: introduce dump_page() and print symbolic flag namesWu Fengguang2010-03-123-13/+84
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - introduce dump_page() to print the page info for debugging some error condition. - convert three mm users: bad_page(), print_bad_pte() and memory offline failure. - print an extra field: the symbolic names of page->flags Example dump_page() output: [ 157.521694] page:ffffea0000a7cba8 count:2 mapcount:1 mapping:ffff88001c901791 index:0x147 [ 157.525570] page flags: 0x100000000100068(uptodate|lru|active|swapbacked) Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Alex Chiang <achiang@hp.com> Cc: Rik van Riel <riel@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Mel Gorman <mel@linux.vnet.ibm.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | mm: do not iterate over NR_CPUS in __zone_pcp_update()Thomas Gleixner2010-03-121-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | __zone_pcp_update() iterates over NR_CPUS instead of limiting the access to the possible cpus. This might result in access to uninitialized areas as the per cpu allocator only populates the per cpu memory for possible cpus. This problem was created as a result of the dynamic allocation of pagesets from percpu memory that went in during the merge window - commit 99dcc3e5a94ed491fbef402831d8c0bbb267f995 ("this_cpu: Page allocator conversion"). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Christoph Lameter <cl@linux-foundation.org> Acked-by: Mel Gorman <mel@csn.ul.ie> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | nommu: fix build breakageKAMEZAWA Hiroyuki2010-03-121-3/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 34e55232e59f7b19050267a05ff1226e5cd122a5 ("mm: avoid false sharing of mm_counter") added sync_mm_rss() for syncing loosely accounted rss counters. It's for CONFIG_MMU but sync_mm_rss is called even in NOMMU enviroment (kerne/exit.c, fs/exec.c). Above commit doesn't handle it well. This patch changes SPLIT_RSS_COUNTING depends on SPLIT_PTLOCKS && CONFIG_MMU And for avoid unnecessary function calls, sync_mm_rss changed to be inlined noop function in header file. Reported-by: David Howells <dhowells@redhat.com> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Michal Simek <monstr@monstr.eu> Signed-off-by: David Howells <dhowells@redhat.com> Cc: Greg Ungerer <gerg@snapgear.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | Driver core: Constify struct sysfs_ops in struct kobj_typeEmese Revfy2010-03-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Constify struct sysfs_ops. This is part of the ops structure constification effort started by Arjan van de Ven et al. Benefits of this constification: * prevents modification of data that is shared (referenced) by many other structure instances at runtime * detects/prevents accidental (but not intentional) modification attempts on archs that enforce read-only kernel data at runtime * potentially better optimized code as the compiler can assume that the const data cannot be changed * the compiler/linker move const data into .rodata and therefore exclude them from false sharing Signed-off-by: Emese Revfy <re.emese@gmail.com> Acked-by: David Teigland <teigland@redhat.com> Acked-by: Matt Domsch <Matt_Domsch@dell.com> Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Acked-by: Hans J. Koch <hjk@linutronix.de> Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> Acked-by: Jens Axboe <jens.axboe@oracle.com> Acked-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* | | | kobject: Constify struct kset_uevent_opsEmese Revfy2010-03-071-1/+1
|/ / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Constify struct kset_uevent_ops. This is part of the ops structure constification effort started by Arjan van de Ven et al. Benefits of this constification: * prevents modification of data that is shared (referenced) by many other structure instances at runtime * detects/prevents accidental (but not intentional) modification attempts on archs that enforce read-only kernel data at runtime * potentially better optimized code as the compiler can assume that the const data cannot be changed * the compiler/linker move const data into .rodata and therefore exclude them from false sharing Signed-off-by: Emese Revfy <re.emese@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* | | mm: add comment on swap_duplicate's error codeHugh Dickins2010-03-061-1/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | swap_duplicate()'s loop appears to miss out on returning the error code from __swap_duplicate(), except when that's -ENOMEM. In fact this is intentional: prior to -ENOMEM for swap_count_continuation, swap_duplicate() was void (and the case only occurs when copy_one_pte() hits a corrupt pte). But that's surprising behaviour, which certainly deserves a comment. Signed-off-by: Hugh Dickins <hughd@google.com> Reported-by: Huang Shijie <shijie8@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | nommu: get_user_pages(): pin last page on non-page-aligned startSteven J. Magnani2010-03-061-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The noMMU version of get_user_pages() fails to pin the last page when the start address isn't page-aligned. The patch fixes this in a way that makes find_extend_vma() congruent to its MMU cousin. Signed-off-by: Steven J. Magnani <steve@digidescorp.com> Acked-by: Paul Mundt <lethal@linux-sh.org> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | vmscan: detect mapped file pages used only onceJohannes Weiner2010-03-062-13/+35
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The VM currently assumes that an inactive, mapped and referenced file page is in use and promotes it to the active list. However, every mapped file page starts out like this and thus a problem arises when workloads create a stream of such pages that are used only for a short time. By flooding the active list with those pages, the VM quickly gets into trouble finding eligible reclaim canditates. The result is long allocation latencies and eviction of the wrong pages. This patch reuses the PG_referenced page flag (used for unmapped file pages) to implement a usage detection that scales with the speed of LRU list cycling (i.e. memory pressure). If the scanner encounters those pages, the flag is set and the page cycled again on the inactive list. Only if it returns with another page table reference it is activated. Otherwise it is reclaimed as 'not recently used cache'. This effectively changes the minimum lifetime of a used-once mapped file page from a full memory cycle to an inactive list cycle, which allows it to occur in linear streams without affecting the stable working set of the system. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: OSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Lee Schermerhorn <lee.schermerhorn@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | vmscan: drop page_mapping_inuse()Johannes Weiner2010-03-061-23/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | page_mapping_inuse() is a historic predicate function for pages that are about to be reclaimed or deactivated. According to it, a page is in use when it is mapped into page tables OR part of swap cache OR backing an mmapped file. This function is used in combination with page_referenced(), which checks for young bits in ptes and the page descriptor itself for the PG_referenced bit. Thus, checking for unmapped swap cache pages is meaningless as PG_referenced is not set for anonymous pages and unmapped pages do not have young ptes. The test makes no difference. Protecting file pages that are not by themselves mapped but are part of a mapped file is also a historic leftover for short-lived things like the exec() code in libc. However, the VM now does reference accounting and activation of pages at unmap time and thus the special treatment on reclaim is obsolete. This patch drops page_mapping_inuse() and switches the two callsites to use page_mapped() directly. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: OSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Lee Schermerhorn <lee.schermerhorn@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | vmscan: factor out page reference checksJohannes Weiner2010-03-061-13/+43
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The used-once mapped file page detection patchset. It is meant to help workloads with large amounts of shortly used file mappings, like rtorrent hashing a file or git when dealing with loose objects (git gc on a bigger site?). Right now, the VM activates referenced mapped file pages on first encounter on the inactive list and it takes a full memory cycle to reclaim them again. When those pages dominate memory, the system no longer has a meaningful notion of 'working set' and is required to give up the active list to make reclaim progress. Obviously, this results in rather bad scanning latencies and the wrong pages being reclaimed. This patch makes the VM be more careful about activating mapped file pages in the first place. The minimum granted lifetime without another memory access becomes an inactive list cycle instead of the full memory cycle, which is more natural given the mentioned loads. This test resembles a hashing rtorrent process. Sequentially, 32MB chunks of a file are mapped into memory, hashed (sha1) and unmapped again. While this happens, every 5 seconds a process is launched and its execution time taken: python2.4 -c 'import pydoc' old: max=2.31s mean=1.26s (0.34) new: max=1.25s mean=0.32s (0.32) find /etc -type f old: max=2.52s mean=1.44s (0.43) new: max=1.92s mean=0.12s (0.17) vim -c ':quit' old: max=6.14s mean=4.03s (0.49) new: max=3.48s mean=2.41s (0.25) mplayer --help old: max=8.08s mean=5.74s (1.02) new: max=3.79s mean=1.32s (0.81) overall hash time (stdev): old: time=1192.30 (12.85) thruput=25.78mb/s (0.27) new: time=1060.27 (32.58) thruput=29.02mb/s (0.88) (-11%) I also tested kernbench with regular IO streaming in the background to see whether the delayed activation of frequently used mapped file pages had a negative impact on performance in the presence of pressure on the inactive list. The patch made no significant difference in timing, neither for kernbench nor for the streaming IO throughput. The first patch submission raised concerns about the cost of the extra faults for actually activated pages on machines that have no hardware support for young page table entries. I created an artificial worst case scenario on an ARM machine with around 300MHz and 64MB of memory to figure out the dimensions involved. The test would mmap a file of 20MB, then 1. touch all its pages to fault them in 2. force one full scan cycle on the inactive file LRU -- old: mapping pages activated -- new: mapping pages inactive 3. touch the mapping pages again -- old and new: fault exceptions to set the young bits 4. force another full scan cycle on the inactive file LRU 5. touch the mapping pages one last time -- new: fault exceptions to set the young bits The test showed an overall increase of 6% in time over 100 iterations of the above (old: ~212sec, new: ~225sec). 13 secs total overhead / (100 * 5k pages), ignoring the execution time of the test itself, makes for about 25us overhead for every page that gets actually activated. Note: 1. File mapping the size of one third of main memory, _completely_ in active use across memory pressure - i.e., most pages referenced within one LRU cycle. This should be rare to non-existant, especially on such embedded setups. 2. Many huge activation batches. Those batches only occur when the working set fluctuates. If it changes completely between every full LRU cycle, you have problematic reclaim overhead anyway. 3. Access of activated pages at maximum speed: sequential loads from every single page without doing anything in between. In reality, the extra faults will get distributed between actual operations on the data. So even if a workload manages to get the VM into the situation of activating a third of memory in one go on such a setup, it will take 2.2 seconds instead 2.1 without the patch. Comparing the numbers (and my user-experience over several months), I think this change is an overall improvement to the VM. Patch 1 is only refactoring to break up that ugly compound conditional in shrink_page_list() and make it easy to document and add new checks in a readable fashion. Patch 2 gets rid of the obsolete page_mapping_inuse(). It's not strictly related to #3, but it was in the original submission and is a net simplification, so I kept it. Patch 3 implements used-once detection of mapped file pages. This patch: Moving the big conditional into its own predicate function makes the code a bit easier to read and allows for better commenting on the checks one-by-one. This is just cleaning up, no semantics should have been changed. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: OSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Lee Schermerhorn <lee.schermerhorn@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | mm: suppress pfn range output for zones without pagesDavid Rientjes2010-03-061-2/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | free_area_init_nodes() emits pfn ranges for all zones on the system. There may be no pages on a higher zone, however, due to memory limitations or the use of the mem= kernel parameter. For example: Zone PFN ranges: DMA 0x00000001 -> 0x00001000 DMA32 0x00001000 -> 0x00100000 Normal 0x00100000 -> 0x00100000 The implementation copies the previous zone's highest pfn, if any, as the next zone's lowest pfn. If its highest pfn is then greater than the amount of addressable memory, the upper memory limit is used instead. Thus, both the lowest and highest possible pfn for higher zones without memory may be the same. The pfn range for zones without memory is now shown as "empty" instead. Signed-off-by: David Rientjes <rientjes@google.com> Cc: Mel Gorman <mel@csn.ul.ie> Reviewed-by: Christoph Lameter <cl@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-29 15:19:00 +0000