In 2009, While running "cache read" performance test of drives behind
SII PMP we encountered a "all 5 drives" timeout on more than 30% of the
machines under test. This patch reduces the rate by a factor of about 70.
Low enough that we didn't care to further investigate the issue.
Performance impact with any sort of "normal" use was ~2%+ CPU and less
than 1% throughput degradation. Worst case impact (cached read) was
6% IOPS reduction. This is with NCQ off (q=1) but I believe FIS based
switching enabled in the SATA driver.
The patch disables "Early ACK" in the 3726 port multiplier.
"Early ACK" is issued when device sends a FIS to the host (via PMP)
and the PMP sends an ACK immediately back to the device - well before
the host gets the response. Under worst case IOPs load (cached read
test) and more than 2 PMPs connected to a 4-port SATA controller,
I suspect the time to service all of the PMPs is exceeding the PMPs
ability to keep track of outstanding FIS it owes the Host. Reducing
the number of PMPs to 2 (or 1) reduces the frequency by several orders
of magnitude. Kudos to Gwendal for initial debugging of this issue.
[Any errors in the description are mine, not his.]
Patch is currently in production on Google servers.
Signed-off-by: Grant Grundler <grundler@google.com>
Signed-off-by: Gwendal Grignou <gwendal@google.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Implicit slab.h inclusion via percpu.h is about to go away. Make sure
gfp.h or slab.h is included as necessary.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Jeff Garzik <jgarzik@pobox.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
It turns out different generations of MCPs have differing quirks.
* MCP 65-73 : FPDMA AA broken, lies about PMP support, forgets to report NCQ
* MCP 77-79 : FPDMA AA broken, lies about PMP support
* MCP 89 : FPDMA AA broken
Instead of turngin off FPDMA AA on all NVIDIAs, implement
HFLAG_NO_FPDMA_AA, define additional board IDs and apply necessary
quirks.
This fixes bko#15481 and the list of quirks is verified by Peer Chen.
http://bugzilla.kernel.org/show_bug.cgi?id=15481
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Peer Chen <pchen@nvidia.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
I've prepared a totally simple patch that, if I did it and measured it
correctly, reduces the text size as of the ppc-6xx-size command of
pata-mpc52xx by more than 10%, by reducing the rodata size from 0x4a4
to 0x17e bytes. This is simply done by changing the data types of the
ATA timing constants.
If you are interested at all, and it's worth the trouble, here the
details:
ppc-6xx-size:
text data bss dec hex filename
old: 6532 1068 0 7600 1db0 pata-mpc52xx.o
new: 5718 1068 0 6786 1a82 pata-mpc52xx.o
The (assembler) code itself doesn't really change very much. I double
checked the final results inside mpc52xx-ata-apply-timings() and they
match. The driver is still working fine of course.
Signed-off-by: Roman Fietze <roman.fietze@telemotive.de>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
ahci over time has grown a number of board IDs and it's a bit of mess
right now. Clean it up such that,
* board_id_* now live in a separate enum board_ids and numbers are
assigned automatically.
* Board IDs assigned to features are separated from the ones assigned
to specific implementations and both are ordered alphabetically.
* For NV MCPs, define per-generation alias board_ids and assign
matching aliases in the pci id table. This makes mcp_linux, 67-73
use board_ahci_mcp65 instead of board_ahci_yesncq. Both are
identical in content.
* Kill now unused board_ahci_nopmp and board_ahci_yesncq.
This patch doesn't cause any functional change but will make future
changes to board_ids and quirks much less painful.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Peer Chen <pchen@nvidia.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
According to section 10.3.1 of the AHCI spec, PxCMD.ST must not be set
unless there's a device attached. Following this saves us a measurable
quantity of power and does not impair hotplug support. Based on a patch
by Kristen Carlson Accardi.
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Cc: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
This can be used for AHCI-compatible interfaces implemented inside
System-On-Chip solutions, or AHCI devices connected via localbus.
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
This patch should contain no functional changes, just moves code
around.
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Factor out some ahci_em_messages handling code from ahci_init_one().
We would like to reuse it for non-PCI devices.
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
To make the function bus-independand we have to get rid of
"struct pci_dev *", so let's pass just "struct devce *".
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
To make the function generic we have to get rid of "struct pci_dev *",
so let's pass just a "struct devce *".
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Make ahci_save_initial_config() a bit more generic by introducing
force_port_map and mask_port_map arguments.
Move PCI stuff into ahci_pci_save_initial_config().
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Currently the driver uses host->iomap to store all the iomapped BARs
of a PCI device (while AHCI devices actually use just a single memory
window).
We're going to teach AHCI to work with non-PCI buses, so there are two
options to make this work:
1. "fake" host->iomap array for non-PCI devices, and place the needed
address at iomap[AHCI_PCI_BAR];
2. Get rid of host->iomap usage, instead introduce a private mmio
field.
This patch implements the second option.
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* 'for-linus' of git://git.infradead.org/users/eparis/notify:
inotify: don't leak user struct on inotify release
inotify: race use after free/double free in inotify inode marks
inotify: clean up the inotify_add_watch out path
Inotify: undefined reference to `anon_inode_getfd'
Manual merge to remove duplicate "select ANON_INODES" from Kconfig file
DA8xx OHCI driver fails to load due to failing clk_get() call for the USB 2.0
clock. Arrange matching USB 2.0 clock by the clock name instead of the device.
(Adding another CLK() entry for "ohci.0" device won't do -- in the future I'll
also have to enable USB 2.0 clock to configure CPPI 4.1 module, in which case
I won't have any device at all.)
Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
inotify_new_group() receives a get_uid-ed user_struct and saves the
reference on group->inotify_data.user. The problem is that free_uid() is
never called on it.
Issue seem to be introduced by 63c882a0 (inotify: reimplement inotify
using fsnotify) after 2.6.30.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Eric Paris <eparis@parisplace.org>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Eric Paris <eparis@redhat.com>
There is a race in the inotify add/rm watch code. A task can find and
remove a mark which doesn't have all of it's references. This can
result in a use after free/double free situation.
Task A Task B
------------ -----------
inotify_new_watch()
allocate a mark (refcnt == 1)
add it to the idr
inotify_rm_watch()
inotify_remove_from_idr()
fsnotify_put_mark()
refcnt hits 0, free
take reference because we are on idr
[at this point it is a use after free]
[time goes on]
refcnt may hit 0 again, double free
The fix is to take the reference BEFORE the object can be found in the
idr.
Signed-off-by: Eric Paris <eparis@redhat.com>
Cc: <stable@kernel.org>
inotify_add_watch explictly frees the unused inode mark, but it can just
use the generic code. Just do that.
Signed-off-by: Eric Paris <eparis@redhat.com>
