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2009-09-11[S390] kernel: always keep machine flags in lowcoreHeiko Carstens1-17/+11
Eleminate the local variable machine_flags and always change machine flags directly in the lowcore. This avoids confusion about when and why the two variables have to be synchronized. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-09-11[S390] clean up linker script using new linker script macros.Nelson Elhage1-76/+7
Note that this patch moves .data.init_task inside _edata. In addition, the alignment of .init.ramfs changes: It is now PAGE_ALIGNED and __initramfs_end is arbitrarily aligned; Previously it was only aligned to a 0x100-byte boundary, and always ended on an even byte. This change results in fewer output sections and in some data being reordered, but should have no functional effect. Signed-off-by: Nelson Elhage <nelhage@ksplice.com> Signed-off-by: Tim Abbott <tabbott@ksplice.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: linux-s390@vger.kernel.org Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-09-11[S390] Use macros for .data.page_aligned.Tim Abbott1-5/+1
.data.page_aligned should not need a separate output section, so as part of this cleanup I moved into the .data output section in the linker scripts in order to eliminate unnecessary references to the section name. Remove the reference to .data.idt, since nothing is put into the .data.idt section on the s390 architecture. It looks like Cyrill Gorcunov posted a patch to remove the .data.idt code on s390 previously: <http://lkml.indiana.edu/hypermail/linux/kernel/0802.2/2536.html> CCing him and the people who acked that patch in case there's a reason it wasn't applied. Signed-off-by: Tim Abbott <tabbott@ksplice.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Acked-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-09-11[S390] move (io|sysc)_restore_trace_psw into .data sectionHendrik Brueckner2-2/+18
The sysc_restore_trace_psw and io_restore_trace_psw storage locations are created in the .text section. When creating and IPLing from a named saved system (NSS), writing to these locations causes a protection exception (because the .text section is mapped as shared read-only in the NSS). To permit write access, move the storage locations into the .data section. The problem occurs only when CONFIG_TRACE_IRQFLAGS is set. The git commmit that has introduced these variables is: 411788ea7fca01ee803af8225ac35807b4d02050 Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-09-11[S390] kernel: Convert upper case scpdata to lower caseHendrik Brueckner1-2/+11
If the CP SET LOADDEV on the 3215 console has been used to specify SCPdata, all data is converted to upper case letters. When scpdata contains upper case letters only, convert all letters to lower case. Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-09-11[S390] kernel: Append scpdata to kernel boot command lineHendrik Brueckner4-27/+172
Append scpdata to the kernel boot command line. If scpdata starts with the equal sign (=), the kernel boot command line is replaced. (For consistency with zIPL and IPL PARM parameters.) To use scpdata for the kernel boot command line, scpdata must consist of ascii characters only. If scpdata contains other characters, scpdata is not appended to the kernel boot command line. In addition, re-IPL is extended for setting scpdata for the next Linux reboot. Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-09-11[S390] tape: use init_timer_on_stack() rather than init_timer()Frank Munzert1-1/+1
With CONFIG_DEBUG_OBJECTS_TIMERS=y "chccwdev --online" for a tape device will fail with message "ODEBUG: object is on stack, but not annotated". We now use init_timer_on_stack. Signed-off-by: Frank Munzert <munzert@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-09-11[S390] proper use of device registerSebastian Ott8-26/+25
Don't use kfree directly after device registration started. Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-09-11[S390] hibernation: merge files and move to kernel/Heiko Carstens6-53/+36
Merge the nearly empty C files and move everything from power/ to kernel/. That way the files are easier to handle. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-09-11[S390] hibernation: remove dead fileHeiko Carstens2-18/+0
There is no caller of do_after_copyback() anywhere. Remove it. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-09-11[S390] atomic ops: small cleanupsHeiko Carstens1-22/+19
Couple of coding style fixes, replace __inline__ with inline and remove #ifdef __KERNEL_- since the header file isn't exported. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-09-11[S390] atomic ops: add effecient atomic64 support for 31 bitHeiko Carstens2-38/+127
Use compare double and swap to implement efficient atomic64 ops for 31 bit. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-09-11[S390] improve mcount codeMartin Schwidefsky3-138/+89
Move the 64 bit mount code from mcount.S into mcount64.S and avoid code duplication. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-09-11[S390] convert/optimize csum_fold() to CHeiko Carstens1-21/+4
In the meantime gcc generates better code than the old inline assemblies do. Original inline assembly results in: lr %r1,%r2 sr %r3,%r3 lr %r2,%r1 srdl %r2,16 alr %r2,%r3 alr %r1,%r2 srl %r1,16 xilf %r1,65535 llghr %r2,%r1 br %r14 Out of the C code gcc generates this: rll %r1,%r2,16 ar %r1,%r2 srl %r1,16 xilf %r1,65535 llghr %r2,%r1 br %r14 In addition we don't have any static register allocations anymore and gcc is free to shuffle instructions around for better pipeline usage. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-09-11[S390] introduce get_clock_monotonicHeiko Carstens2-1/+16
Introduce get_clock_monotonic() function which can be used to get a (fast) timestamp. Resolution is the same as for get_clock(). The only difference is that the timestamps are monotonic and don't jump backward or forward. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-09-11[S390] dasd: fix message namingStefan Haberland8-20/+20
This patch fixes message naming so that generic dasd messages do not contain the device discipline. For this purpose the dev_ makros are replaced by pr_ makros for generic dasd messages. Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-09-11[S390] dasd: optimize cpu usage in goodcaseStefan Haberland7-51/+41
remove unnecessary dbf call, remove string operations for magic Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-09-11[S390] dasd: fail requests when device state is less then readyStefan Weinhuber1-1/+4
A DASD device that is not ready or online has no defined disk layout, so all requests that arrive in such a state need to be returned as failed. Signed-off-by: Stefan Weinhuber <wein@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-09-11[S390] cio: remove ccw_device init_nameSebastian Ott2-19/+6
We used the init_name to set the console ccw_device's name early at the boot stage. This patch moves the name setting (for all ccw devices) to the point where we actually register the device. At this time we can do dynamic allocations and therefore use dev_set_name. Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-09-11[S390] cio: move final put_device to ccw_device_unregisterSebastian Ott1-3/+4
We use a test_and_clear_bit to prevent a device from being unregistered twice. Unfortunately in this cases the "final" put_device (from device_initialize) was issued more than once, resulting in an use after free error. Fix this by moving this put_device to ccw_device_unregister. Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-09-11[S390] cio: remove subchannel init_nameSebastian Ott3-14/+2
We used the init_name to set the console subchannels name early at the boot stage. With the patch cio: fix memleak in subchannel validation we moved the name setting to the point where we actually register the console subchannel. At this time we can do dynamic allocations and therefore use dev_set_name. Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-09-11[S390] cio: fix memleak in subchannel validationSebastian Ott2-5/+5
When scanning for new subchannels we have a code path where we allocate memory for a struct subchannel, set the device name (which is dynamically allocated now) and do a check if the underlying device is blacklisted - if so we free the subchannel structure. Since we have not set up refcounting at this stage, the device name's memory is lost. Fix this by moving the dev_set_name after the blacklist test. Note: With this patch the init_name for the console subchannel becomes virtually obsolete. Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-09-11[S390] cio: fix use after free in s390 debug featureSebastian Ott1-5/+9
When using s390dbf with "%s" in sprintf format strings the string itself is not copied to the dbf buffer. Since in this case only pointers are stored in the s390dbf, we should not use dev_name - which is bound to the lifetime of the device. Reading this entry from s390dbf after the device was released will cause an use after free error. Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-09-11[S390] qdio: remove limited number of debugfs entriesJan Glauber2-41/+18
The number of qdio debugfs entries was limited. Remove this limit and group the queue files in a per device directory. Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-09-11[S390] cio: failing set online/offline processing.Michael Ernst2-35/+67
When unit checks trigger sensing the device state is set to W4SENSE until sense completion; then the device state is set back to ONLINE. If a unit check occurs while set online or set offline requests are processed then it might happen that the device's temporary W4SENSE state causes these functions to terminate, leaving the device in an inconsistent state when the state is set back to ONLINE later on so that the device cannot be set online or offline any longer. To solve this, set online/offline and related rollback or error routines are processed only if the device is in a final or DISCONNECTED state. Signed-off-by: Michael Ernst <mernst@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-09-11[S390] cio: ensure to hold a reference for deferred deregistrationSebastian Ott1-8/+6
Ensure to always hold an extra device reference for scheduling a subchannel deregistration, by moving the get_device to ccw_device_schedule_sch_unregister. This fixes an use after free error in ccw_device_call_sch_unregister where put_device was called on an already freed device structure. Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-09-11[S390] qdio: continue polling if the queue is not finishedJan Glauber1-1/+3
With commit c38f96080955854e54df9cb392bc674e1ae330e1 polling was stopped for the queue even if new data is available. Return immediately after scheduling the queue tasklet if the queue is not done. Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-09-11[S390] cio: increase trace levelSebastian Ott2-31/+17
Move debug traces for start I/O and interrupt events to exclusive trace levels. Also change tracing in hot-path from sprintf (costly) to hex. Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-09-11[S390] cio: fix not oper handling after failed [on|off]line processingSebastian Ott1-0/+7
If online/offline processing of a ccw device fails, resulting in not operational state, notify the driver and unregister the device in case the driver dosn't want to keep it. Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-09-11[S390] cio: consolidate subchannel intparm resetPeter Oberparleiter2-10/+3
Ensure that the hardware interruption parameter for a subchannel is reset when the associated subchannel data structure is freed. Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-09-11[S390] cio: move scsw helper functions to header fileHeiko Carstens5-363/+259
All scsw helper functions are very short and usage of them shouldn't result in function calls. Therefore we move them to a separate header file. Also saves a lot of EXPORT_SYMBOLs. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-09-11[S390] cio: fix ineffective verify eventPeter Oberparleiter1-1/+12
Path verification events occurring for offline devices are currently ignored. As a result, offline devices are not removed, even though they might no longer be accessible (for example because the last path to the device was varied offline). Fix this by scheduling a status evaluation for the affected subchannel when a path verification event occurs. Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-09-11writeback: check for registered bdi in flusher add and inode dirtyJens Axboe3-0/+16
Also a debugging aid. We want to catch dirty inodes being added to backing devices that don't do writeback. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-09-11writeback: add name to backing_dev_infoJens Axboe17-0/+18
This enables us to track who does what and print info. Its main use is catching dirty inodes on the default_backing_dev_info, so we can fix that up. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-09-11writeback: add some debug inode list counters to bdi statsJens Axboe1-4/+34
Add some debug entries to be able to inspect the internal state of the writeback details. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-09-11writeback: get rid of pdflush completelyJens Axboe4-282/+6
It is now unused, so kill it off. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-09-11writeback: switch to per-bdi threads for flushing dataJens Axboe10-472/+1120
This gets rid of pdflush for bdi writeout and kupdated style cleaning. pdflush writeout suffers from lack of locality and also requires more threads to handle the same workload, since it has to work in a non-blocking fashion against each queue. This also introduces lumpy behaviour and potential request starvation, since pdflush can be starved for queue access if others are accessing it. A sample ffsb workload that does random writes to files is about 8% faster here on a simple SATA drive during the benchmark phase. File layout also seems a LOT more smooth in vmstat: r b swpd free buff cache si so bi bo in cs us sy id wa 0 1 0 608848 2652 375372 0 0 0 71024 604 24 1 10 48 42 0 1 0 549644 2712 433736 0 0 0 60692 505 27 1 8 48 44 1 0 0 476928 2784 505192 0 0 4 29540 553 24 0 9 53 37 0 1 0 457972 2808 524008 0 0 0 54876 331 16 0 4 38 58 0 1 0 366128 2928 614284 0 0 4 92168 710 58 0 13 53 34 0 1 0 295092 3000 684140 0 0 0 62924 572 23 0 9 53 37 0 1 0 236592 3064 741704 0 0 4 58256 523 17 0 8 48 44 0 1 0 165608 3132 811464 0 0 0 57460 560 21 0 8 54 38 0 1 0 102952 3200 873164 0 0 4 74748 540 29 1 10 48 41 0 1 0 48604 3252 926472 0 0 0 53248 469 29 0 7 47 45 where vanilla tends to fluctuate a lot in the creation phase: r b swpd free buff cache si so bi bo in cs us sy id wa 1 1 0 678716 5792 303380 0 0 0 74064 565 50 1 11 52 36 1 0 0 662488 5864 319396 0 0 4 352 302 329 0 2 47 51 0 1 0 599312 5924 381468 0 0 0 78164 516 55 0 9 51 40 0 1 0 519952 6008 459516 0 0 4 78156 622 56 1 11 52 37 1 1 0 436640 6092 541632 0 0 0 82244 622 54 0 11 48 41 0 1 0 436640 6092 541660 0 0 0 8 152 39 0 0 51 49 0 1 0 332224 6200 644252 0 0 4 102800 728 46 1 13 49 36 1 0 0 274492 6260 701056 0 0 4 12328 459 49 0 7 50 43 0 1 0 211220 6324 763356 0 0 0 106940 515 37 1 10 51 39 1 0 0 160412 6376 813468 0 0 0 8224 415 43 0 6 49 45 1 1 0 85980 6452 886556 0 0 4 113516 575 39 1 11 54 34 0 2 0 85968 6452 886620 0 0 0 1640 158 211 0 0 46 54 A 10 disk test with btrfs performs 26% faster with per-bdi flushing. A SSD based writeback test on XFS performs over 20% better as well, with the throughput being very stable around 1GB/sec, where pdflush only manages 750MB/sec and fluctuates wildly while doing so. Random buffered writes to many files behave a lot better as well, as does random mmap'ed writes. A separate thread is added to sync the super blocks. In the long term, adding sync_supers_bdi() functionality could get rid of this thread again. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-09-11writeback: move dirty inodes from super_block to backing_dev_infoJens Axboe6-84/+165
This is a first step at introducing per-bdi flusher threads. We should have no change in behaviour, although sb_has_dirty_inodes() is now ridiculously expensive, as there's no easy way to answer that question. Not a huge problem, since it'll be deleted in subsequent patches. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-09-11writeback: get rid of generic_sync_sb_inodes() exportJens Axboe7-68/+58
This adds two new exported functions: - writeback_inodes_sb(), which only attempts to writeback dirty inodes on this super_block, for WB_SYNC_NONE writeout. - sync_inodes_sb(), which writes out all dirty inodes on this super_block and also waits for the IO to complete. Acked-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-09-11pata_rz1000: use printk_onceMarcin Slusarz1-3/+1
Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
2009-09-11ahci: kill @force_restart and refine CLO for ahci_kick_engine()Shane Huang1-12/+10
This patch refines ahci_kick_engine() after discussion with Tejun about FBS(FIS-based switching) support preparation: a. Kill @force_restart and always kick the engine. The only case where @force_restart is zero is when it's called from ahci_p5wdh_hardreset() Actually at that point, BSY is pretty much guaranteed to be set. b. If PMP is attached, ignore busy and always do CLO. (AHCI-1.3 9.2) Signed-off-by: Shane Huang <shane.huang@amd.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
2009-09-11pata_cs5535: add pci id for AMD based CS5535 controllersOtavio Salvador2-1/+3
Signed-off-by: Otavio Salvador <otavio@ossystems.com.br> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
2009-09-11ahci: Add AMD SB900 SATA/IDE controller device IDsShane Huang5-1/+14
Add AMD SB900 SATA/IDE controller device IDs. Signed-off-by: Shane Huang <shane.huang@amd.com> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
2009-09-11drivers/ata: use resource_sizeJulia Lawall4-7/+7
Use the function resource_size, which reduces the chance of introducing off-by-one errors in calculating the resource size. The semantic patch that makes this change is as follows: (http://www.emn.fr/x-info/coccinelle/) // <smpl> @@ struct resource *res; @@ - (res->end - res->start) + 1 + resource_size(res) // </smpl> Signed-off-by: Julia Lawall <julia@diku.dk> Cc: Jeff Garzik <jeff@garzik.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
2009-09-10Merge branch 'mad' into for-linusRoland Dreier3-8/+34
Conflicts: drivers/infiniband/core/mad.c
2009-09-10Merge branches 'cxgb3', 'ehca', 'ipath', 'ipoib', 'misc', 'mlx4', 'mthca' and 'nes' into for-linusRoland Dreier50-510/+1096
2009-09-11Merge branch 'next' into for-linusJames Morris97-609/+2245
2009-09-10md: Fix "strchr" [drivers/md/dm-log-userspace.ko] undefined!Geert Uytterhoeven1-1/+1
Commit b8313b6da7e2e7c7f47d93d8561969a3ff9ba0ea ("dm log: remove incorrect field from userspace table output") added a call to strstr() with a single-character "needle" string parameter. Unfortunately some versions of gcc replace such calls to strstr() by calls to strchr() behind our back. This causes linking errors if strchr() is defined as an inline function in <asm/string.h> (e.g. on m68k): | WARNING: "strchr" [drivers/md/dm-log-userspace.ko] undefined! Avoid this by explicitly calling strchr() instead. Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-10sched: Fix sched::sched_stat_wait tracepoint fieldIngo Molnar1-2/+1
This weird perf trace output: cc1-9943 [001] 2802.059479616: sched_stat_wait: task: as:9944 wait: 2801938766276 [ns] Is caused by setting one component field of the delta to zero a bit too early. Move it to later. ( Note, this does not affect the NEW_FAIR_SLEEPERS interactivity bug, it's just a reporting bug in essence. ) Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Nikos Chantziaras <realnc@arcor.de> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <4AA93D34.8040500@arcor.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-10sched: Disable NEW_FAIR_SLEEPERS for nowIngo Molnar1-1/+1
Nikos Chantziaras and Jens Axboe reported that turning off NEW_FAIR_SLEEPERS improves desktop interactivity visibly. Nikos described his experiences the following way: " With this setting, I can do "nice -n 19 make -j20" and still have a very smooth desktop and watch a movie at the same time. Various other annoyances (like the "logout/shutdown/restart" dialog of KDE not appearing at all until the background fade-out effect has finished) are also gone. So this seems to be the single most important setting that vastly improves desktop behavior, at least here. " Jens described it the following way, referring to a 10-seconds xmodmap scheduling delay he was trying to debug: " Then I tried switching NO_NEW_FAIR_SLEEPERS on, and then I get: Performance counter stats for 'xmodmap .xmodmap-carl': 9.009137 task-clock-msecs # 0.447 CPUs 18 context-switches # 0.002 M/sec 1 CPU-migrations # 0.000 M/sec 315 page-faults # 0.035 M/sec 0.020167093 seconds time elapsed Woot! " So disable it for now. In perf trace output i can see weird delta timestamps: cc1-9943 [001] 2802.059479616: sched_stat_wait: task: as:9944 wait: 2801938766276 [ns] That nsec field is not supposed to be that large. More digging is needed - but lets turn it off while the real bug is found. Reported-by: Nikos Chantziaras <realnc@arcor.de> Tested-by: Nikos Chantziaras <realnc@arcor.de> Reported-by: Jens Axboe <jens.axboe@oracle.com> Tested-by: Jens Axboe <jens.axboe@oracle.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <4AA93D34.8040500@arcor.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>