While testing an application using the xpmem (out of kernel) driver, we
noticed a significant page fault rate reduction of x86_64 with respect
to ia64. For one test running with 32 cpus, one thread per cpu, it
took 01:08 for each of the threads to vm_insert_pfn 2GB worth of pages.
For the same test running on 256 cpus, one thread per cpu, it took 14:48
to vm_insert_pfn 2 GB worth of pages.
The slowdown was tracked to lookup_memtype which acquires the
spinlock memtype_lock. This heavily contended lock was slowing down
vm_insert_pfn().
With the cmpxchg on page->flags method, both the 32 cpu and 256 cpu
cases take approx 00:01.3 seconds to complete.
Signed-off-by: Robin Holt <holt@sgi.com>
LKML-Reference: <20100423153627.751194346@gulag1.americas.sgi.com>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@gmail.com>
Cc: Rafael Wysocki <rjw@novell.com>
Reviewed-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Move pat backend to fully rbtree based implementation from the existing
rbtree and linked list hybrid.
New rbtree based solution uses interval trees (augmented rbtrees) in
order to store the PAT ranges. The new code seprates out the pat backend
to pat_rbtree.c file, making is cleaner. The change also makes the PAT
lookup, reserve and free operations more optimal, as we don't have to
traverse linear linked list of few tens of entries in normal case.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
LKML-Reference: <20100210232607.GB11465@linux-os.sc.intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Minor changes in pat.c to cleanup code and make it smoother to introduce
bigger rbtree only change in the following patch. The changes are cleaup
only and should not have any functional impact.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
LKML-Reference: <20100210195909.792781000@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/anholt/drm-intel:
drm/i915: hold ref on flip object until it completes
drm/i915: Fix crash while aborting hibernation
drm/i915: Correctly return -ENOMEM on allocation failure in cmdbuf ioctls.
drm/i915: fix pipe source image setting in flip command
drm/i915: fix flip done interrupt on Ironlake
drm/i915: untangle page flip completion
drm/i915: handle FBC and self-refresh better
drm/i915: Increase fb alignment to 64k
drm/i915: Update write_domains on active list after flush.
drm/i915: Rework DPLL calculation parameters for Ironlake
Replace the zero-division warning message with WARN_ON_ONCE() per the
advice by Linus. This shouldn't happen, but if it happens, it's
possible that the bug happens often due to buggy IRQs.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Mike Frysinger pointed out that calling tracehook_signal_handler with
stepping=0 missed testing the thread flags, resulting in not calling
ptrace_notify. Fix this by testing if we're single stepping or branch
stepping and setting the flag accordingly.
Tested, seems to work.
Reported-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/lrg/voltage-2.6:
regulator/lp3971: vol_map out of bounds in lp3971_{ldo,dcdc}_set_voltage()
regulator: Fix display of null constraints for regulators
After `for (val = LDO_VOL_MIN_IDX; val <= LDO_VOL_MAX_IDX; val++)', if no break
occurs, val reaches LDO_VOL_MIN_IDX + 1, which is out of bounds for
ldo45_voltage_map[] and ldo123_voltage_map[].
Similarly BUCK_TARGET_VOL_MAX_IDX + 1 is out of bounds for buck_voltage_map[].
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>
If the regulator constraints are empty and there is no voltage
reported then nothing will be added to the text displayed for the
constraints, leading to random stack data being printed. This is
unlikely to happen for practical regulators since most will at
least report a voltage but should still be fixed.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: stable@kernel.org
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>
This patch solves a corner case during allocation which occurs if both
metadata (indirect) and data blocks are required but there is an
obstacle in the filesystem (e.g. a resource group header or another
allocated block) such that when the allocation is requested only
enough blocks for the metadata are returned.
By changing the exit condition of this loop, we ensure that a
minimum of one data block will always be returned.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
We need this one-liner to signal the mount helper of the 'insufficient journals' condition.
Signed-off-by: Abhijith Das <adas@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
cciss: Make cciss_seq_show handle holes in the h->drv[] array
cfq-iosched: split seeky coop queues after one slice
* 'bugfixes' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6:
NFS: Fix the mapping of the NFSERR_SERVERFAULT error
NFS: Remove a redundant check for PageFsCache in nfs_migrate_page()
NFS: Fix a bug in nfs_fscache_release_page()
* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-rc-fixes-2.6:
[SCSI] qla2xxx: Obtain proper host structure during response-queue processing.
[SCSI] compat_ioct: fix bsg SG_IO
[SCSI] qla2xxx: make msix interrupt handler safe for irq
[SCSI] zfcp: Report FC BSG errors in correct field
[SCSI] mptfusion : mptscsih_abort return value should be SUCCESS instead of value 0.
* 'drm-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6: (30 commits)
vgaarb: fix incorrect dereference of userspace pointer.
drm/radeon/kms: retry auxch on 0x20 timeout value.
drm/radeon: Skip dma copy test in benchmark if card doesn't have dma engine.
drm/vmwgfx: Fix a circular locking dependency bug.
drm/vmwgfx: Drop scanout flag compat and add execbuf ioctl parameter members. Bumps major.
drm/vmwgfx: Report propper framebuffer_{max|min}_{width|height}
drm/vmwgfx: Update the user-space interface.
drm/radeon/kms: fix screen clearing before fbcon.
nouveau: fix state detection with switchable graphics
drm/nouveau: move dereferences after null checks
drm/nv50: make the pgraph irq handler loop like the pre-nv50 version
drm/nv50: delete ramfc object after disabling fifo, not before
drm/nv50: avoid unloading pgraph context when ctxprog is running
drm/nv50: align size of buffer object to the right boundaries.
drm/nv50: disregard dac outputs in nv50_sor_dpms()
drm/nv50: prevent multiple init tables being parsed at the same time
drm/nouveau: make dp auxch xfer len check for reads only
drm/nv40: make INIT_COMPUTE_MEM a NOP, just like nv50
drm/nouveau: Add proper vgaarb support.
drm/nouveau: Fix fbcon on mixed pre-NV50 + NV50 multicard.
...
Robin Holt
Pallipadi, Venkatesh
Linus Torvalds
Takashi Iwai
Kyle McMartin
Roel Kluin
Mark Brown
Steven Whitehouse
Abhijith Das