New sysctl tcp_frto_response is added to select amongst these
responses:
- Rate halving based; reuses CA_CWR state (default)
- Very conservative; used to be the only one available (=1)
- Undo cwr; undoes ssthresh and cwnd reductions (=2)
The response with rate halving requires a new parameter to
tcp_enter_cwr because FRTO has already reduced ssthresh and
doing a second reduction there has to be prevented. In addition,
to keep things nice on 80 cols screen, a local variable was
added.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
I noticed in oprofile study a cache miss in tcp_rcv_established() to read
copied_seq.
ffffffff80400a80 <tcp_rcv_established>: /* tcp_rcv_established total: 4034293
2.0400 */
55493 0.0281 :ffffffff80400bc9: mov 0x4c8(%r12),%eax copied_seq
543103 0.2746 :ffffffff80400bd1: cmp 0x3e0(%r12),%eax rcv_nxt
if (tp->copied_seq == tp->rcv_nxt &&
len - tcp_header_len <= tp->ucopy.len) {
In this function, the cache line 0x4c0 -> 0x500 is used only for this
reading 'copied_seq' field.
rcv_wup and copied_seq should be next to rcv_nxt field, to lower number of
active cache lines in hot paths. (tcp_rcv_established(), tcp_poll(), ...)
As you suggested, I changed tcp_create_openreq_child() so that these fields
are changed together, to avoid adding a new store buffer stall.
Patch is 64bit friendly (no new hole because of alignment constraints)
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This interpretation comes from RFC4138:
"If the sender implements some loss recovery algorithm other
than Reno or NewReno [FHG04], the F-RTO algorithm SHOULD
NOT be entered when earlier fast recovery is underway."
I think the RFC means to say (especially in the light of
Appendix B) that ...recovery is underway (not just fast recovery)
or was underway when it was interrupted by an earlier (F-)RTO
that hasn't yet been resolved (snd_una has not advanced enough).
Thus, my interpretation is that whenever TCP has ever
retransmitted other than head, basic version cannot be used
because then the order assumptions which are used as FRTO basis
do not hold.
NewReno has only the head segment retransmitted at a time.
Therefore, walk up to the segment that has not been SACKed, if
that segment is not retransmitted nor anything before it, we know
for sure, that nothing after the non-SACKed segment should be
either. This assumption is valid because TCPCB_EVER_RETRANS does
not leave holes but each non-SACKed segment is rexmitted
in-order.
Check for retrans_out > 1 avoids more expensive walk through the
skb list, as we can know the result beforehand: F-RTO will not be
allowed.
SACKed skb can turn into non-SACked only in the extremely rare
case of SACK reneging, in this case we might fail to detect
retransmissions if there were them for any other than head. To
get rid of that feature, whole rexmit queue would have to be
walked (always) or FRTO should be prevented when SACK reneging
happens. Of course RTO should still trigger after reneging which
makes this issue even less likely to show up. And as long as the
response is as conservative as it's now, nothing bad happens even
then.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
The ACPI spec defines the bit and Microsoft uses it,
so Linux must use it too.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Add input_set_capability() helper used to indicate that an input
device supports a certain event without need to manipulate bitmaps
directly.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
A security issue is emerging. Disallow Routing Header Type 0 by default
as we have been doing for IPv4.
Note: We allow RH2 by default because it is harmless.
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Replace uses with of_find_node_by_name and for_each_node_by_name.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This is an old interface and is replaced by of_find_compatible_node.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
BenH's commit a741e67969 in powerpc.git,
although (AFAICT) only intended to affect ppc64, also has side-effects
which break 44x. I think 40x, 8xx and Freescale Book E are also
affected, though I haven't tested them.
The problem lies in unconditionally removing flush_tlb_pending() from
the versions of flush_tlb_mm(), flush_tlb_range() and
flush_tlb_kernel_range() used on ppc64 - which are also used the
embedded platforms mentioned above.
The patch below cleans up the convoluted #ifdef logic in tlbflush.h,
in the process restoring the necessary flushes for the software TLB
platforms. There are three sets of definitions for the flushing
hooks: the software TLB versions (revised to avoid using names which
appear to related to TLB batching), the 32-bit hash based versions
(external functions) amd the 64-bit hash based versions (which
implement batching).
It also moves the declaration of update_mmu_cache() to always be in
tlbflush.h (previously it was in tlbflush.h except for PPC64, where it
was in pgtable.h).
Booted on Ebony (440GP) and compiled for 64-bit and 32-bit
multiplatform.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Save the trap number in the case of getting a bad stack in an exception
handler. It is sometimes useful to know what exception it was that caused
this to happen. Without this, no trap number is reported.
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Rename MPIC_BROKEN_U3 to something a little more descriptive. Its
effect is to enable support for HT irqs behind the PCI-X/HT bridge on
U3/U4 (aka. CPC9x5) parts.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This patch adds a driver to arch/powerpc/sysdev for the UIC, the
on-chip interrupt controller from IBM/AMCC 4xx chips. It uses the new
irq host mapping infrastructure.
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
For cases when probes are placed on instructions that can be emulated,
don't take the single-step exception.
Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Oprofile support for PA6T, kernel side.
Also rename the PA6T_SPRN.* defines to SPRN_PA6T.*.
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>
PowerPC 750CL has high BATs. The patch below adds a CPU_FTRS_750CL that
includes that. Without it, the original firmware mappings in the high BATs
aren't cleared which continue to override the linux translations.
It also adds CPU_FTR_COMMON to CPU_FTRS_750GX for completeness.
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The of_iomap function maps memory for a given
device_node and returns a pointer to that memory.
This is used at some places, so it makes sense to
a seperate function.
Signed-off-by: Christian Krafft <krafft@de.ibm.com>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
This patch adds code to deal with conversion of
logical cpu to cbe nodes. It removes code that
assummed there were two logical CPUs per CBE.
Signed-off-by: Christian Krafft <krafft@de.ibm.com>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Until now, we have always entered the spu page fault handler
with a mutex for the spu context held. This has multiple
bad side-effects:
- it becomes impossible to suspend the context during
page faults
- if an spu program attempts to access its own mmio
areas through DMA, we get an immediate livelock when
the nopage function tries to acquire the same mutex
This patch makes the page fault logic operate on a
struct spu_context instead of a struct spu, and moves it
from spu_base.c to a new file fault.c inside of spufs.
We now also need to copy the dar and dsisr contents
of the last fault into the saved context to have it
accessible in case we schedule out the context before
activating the page fault handler.
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
This patch removes the unnecessary bit number from CKENnn_XXXX
definitions for PXA, so that
CKEN0_PWM0 --> CKEN_PWM0
CKEN1_PWM1 --> CKEN_PWM1
...
CKEN24_CAMERA --> CKEN_CAMERA
The reasons for the change of these defitions are:
1. they do not scale - they are currently valid for pxa2xx, but
definitely not valid for pxa3xx, e.g., pxa3xx has bit 3 for camera
instead of bit 24
2. they are unnecessary - the peripheral name within the definition
has already announced its usage, we don't need those bit numbers
to know which peripheral we are going to enable/disable clock for
3. they are inconvenient - think about this: a driver programmer
for pxa has to remember which bit in the CKEN register to turn
on/off
Another change in the patch is to make the definitions equal to its
clock bit index, so that
#define CKEN_CAMERA (24)
instead of
#define CKEN_CAMERA (1 << 24)
this change, however, will add a run-time bit shift operation in
pxa_set_cken(), but the benefit of this change is that it scales
when bit index exceeds 32, e.g., pxa3xx has two registers CKENA
and CKENB, totally 64 bit for this, suppose CAMERA clock enabling
bit is CKENB:10, one can simply define CKEN_CAMERA to be (32 + 10)
and so that pxa_set_cken() need minimum change to adapt to that.
Signed-off-by: eric miao <eric.y.miao@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Remove the use of struct s3c24xx_board as
this is just as easily done by using the
platform device registration functions to
make the initialisation sequence easier.
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Remove the clocks from the s3c24xx_board as part
of the process of simplifying the initialisation
sequence by removing struct s3c24xx_board.
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The support for that machine is not yet complete, but it's enough to
be useful as a test platform for the serial and ethernet driver.
Moreover a typo in the product name is fixed that I missed in the
last patch.
Signed-off-by: Uwe Kleine-König <ukleinek@informatik.uni-freiburg.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Add Intel KIXRP435 Reference Platform based on IXP43x processor.
Fixed after review : access to cp15 removed in identification functions,
used access to global processor_id instead
Signed-off-by: Vladimir Barinov <vbarinov@ru.mvista.com>
Signed-off-by: Ruslan Sushko <rsushko@ru.mvista.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This patch brings generic gpio layer support to ixp4xx. It creates
functions needed for gpio->irq and irq->gpio translation.
It expects and initial value to be passed to
gpio_direction_output() which has been introduced by
commit 28735a7253 in Linus git tree.
Generic gpio layer is going to be used by pxa2xx_udc driver.
Signed-off-by: Milan Svoboda <msvoboda@ra.rockwell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The function attribute const is abused here as the PLL register is read. But I
think this is all right because the PLL register cannot change without a reset.
Note: This patch depends on 4293/1
Signed-off-by: Uwe Kleine-König <ukleinek@informatik.uni-freiburg.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This implies that REGGET gets a new parameter "var" to allow to hold the actual
register value in a variable.
Moreover REGGET was broken because it used "field" instead of
"reg ## _ ## field" which proves that there are no callers to fix :-)
Signed-off-by: Uwe Kleine-König <ukleinek@informatik.uni-freiburg.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Reposted patch for kernel 2.6.21-rc2.
The driver i2c-pxa doesn't set the class member in i2c_adapter, which
is used to register the I2C adapter. The hwmon (sensors) drivers (e.g.
adm1021) that are connected to a i2c-pxa adapter don't attach because
they expect that the adapter supports class I2C_CLASS_HWMON.
This patch adds functionality to allow platforms to set the class and
pass it as platform_data to the i2c-pxa driver. Sample usage in
platform code:
static struct i2c_pxa_platform_data my_i2c_platform_data = {
.class = I2C_CLASS_HWMON
};
static void __init my_platform_init(void)
{
(void) platform_add_devices(devices, ARRAY_SIZE(devices));
pxa_set_i2c_info(&my_i2c_platform_data);
}
Signed-off-by: Matej Kenda <matej.kenda@hermes-softlab.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
I've traced down an off-by-one TCP checksum calculation error under
the following conditions:
1) The TCP code needs to split a full-sized packet due to a reduced
MSS (typically due to the addition of TCP options mid-stream like
SACK).
_AND_
2) The checksum of the 2nd fragment is larger than the checksum of the
original packet. After subtraction this results in a checksum for
the 1st fragment with bits 16..31 set to 1. (this is ok)
_AND_
3) The checksum of the 1st fragment's TCP header plus the previously
32bit checksum of the 1st fragment DOES NOT cause a 32bit overflow
when added together. This results in a checksum of the TCP header
plus TCP data that still has the upper 16 bits as 1's.
_THEN_
4) The TCP+data checksum is added to the checksum of the pseudo IP
header with csum_tcpudp_nofold() incorrectly (the bug).
The problem is the checksum of the TCP+data is passed to
csum_tcpudp_nofold() as an 32bit unsigned value, however the assembly
code acts on it as if it is a 64bit unsigned value.
This causes an incorrect 32->64bit extension if the sum has bit 31
set. The resulting checksum is off by one.
This problems is data and TCP header dependent due to #2 and #3
above so it doesn't occur on every TCP packet split.
Signed-off-by: Dave Johnson <djohnson+linux-mips@sw.starentnetworks.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
With commit 63dc68a8cf, kernel can not
handle BUG() and BUG_ON() properly since get_user() returns false for
kernel code. Use __get_user() to skip unnecessary access_ok(). This
patch also make BRK_BUG code encoded in the TNE instruction.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The save_fp_context()/restore_fp_context() might sleep on accessing
user stack and therefore might lose FPU ownership in middle of them.
If these function failed due to "in_atomic" test in do_page_fault,
touch the sigcontext area in non-atomic context and retry these
save/restore operation.
This is a replacement of a (broken) fix which was titled "Allow CpU
exception in kernel partially".
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The commit 4d40bff7110e9e1a97ff8c01bdd6350e9867cc10 ("Allow CpU
exception in kernel partially") was broken. The commit was to fix
theoretical problem but broke usual case. Revert it for now.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Recent versions of the BCM112X processors aren't recognized by Linux
(preventing Linux from booting on those processors). This patch adds
support for those that are missing.
Signed-off-by: Mark Mason <mason@broadcom.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Add a 'quirks' module parameter for the usbhid module, so users can
add or modify quirks at module load time.
Signed-off-by: Paul Walmsley <paul@booyaka.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Add internal support for dynamically-allocated HID quirks, "dquirks"
(for "dynamic quirks"). Includes several functions to add/modify quirks
from the list. This code is used by the next patch to implement quirk
modification upon module load.
Signed-off-by: Paul Walmsley <paul@booyaka.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
