Add an API to return free tags, blk-mq-tag will use it.
Note, this just returns a snapshot of free tags number. blk-mq-tag has
two usages of it. One is for info output for diagnosis. The other is to
quickly check if there are free tags for request dispatch checking.
Neither requires very precise.
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Add a new API to iterate free ids. blk-mq-tag will use it.
Note, this doesn't guarantee to iterate all free ids restrictly. Caller
should be aware of this. blk-mq uses it to do sanity check for request
timedout, so can tolerate the limitation.
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Make percpu_ida percpu size/batch configurable. The block-mq-tag will
use it.
After block-mq uses percpu_ida to manage tags, performance is improved.
My test is done in a 2 sockets machine, 12 process cross the 2 sockets.
So if there is lock contention or ipi, should be stressed heavily.
Testing is done for null-blk.
hw_queue_depth nopatch iops patch iops
64 ~800k/s ~1470k/s
2048 ~4470k/s ~4340k/s
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
In my usage, sometimes the percpu APIs are called with irq locked,
sometimes not. lockdep complains there is potential deadlock. Let's
always use percpucounter lock in irq safe way. There should be no
performance penality, as all those are slow code path.
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Useful for locating buggy drivers on kernel oops.
It may add dozens of new lines to boot dmesg. DEBUG_KOBJECT_RELEASE is
hopefully only enabled in debug kernels (like maybe the Fedora rawhide
one, or at developers), so being a bit more verbose is likely ok.
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull networking changes from David Miller:
1) Multiply in netfilter IPVS can overflow when calculating destination
weight. From Simon Kirby.
2) Use after free fixes in IPVS from Julian Anastasov.
3) SFC driver bug fixes from Daniel Pieczko.
4) Memory leak in pcan_usb_core failure paths, from Alexey Khoroshilov.
5) Locking and encapsulation fixes to serial line CAN driver, from
Andrew Naujoks.
6) Duplex and VF handling fixes to bnx2x driver from Yaniv Rosner,
Eilon Greenstein, and Ariel Elior.
7) In lapb, if no other packets are outstanding, T1 timeouts actually
stall things and no packet gets sent. Fix from Josselin Costanzi.
8) ICMP redirects should not make it to the socket error queues, from
Duan Jiong.
9) Fix bugs in skge DMA mapping error handling, from Nikulas Patocka.
10) Fix setting of VLAN priority field on via-rhine driver, from Roget
Luethi.
11) Fix TX stalls and VLAN promisc programming in be2net driver from
Ajit Khaparde.
12) Packet padding doesn't get handled correctly in new usbnet SG
support code, from Ming Lei.
13) Fix races in netdevice teardown wrt. network namespace closing.
From Eric W. Biederman.
14) Fix potential missed initialization of net_secret if not TCP
connections are openned. From Eric Dumazet.
15) Cinterion PLXX product ID in qmi_wwan driver is wrong, from
Aleksander Morgado.
16) skb_cow_head() can change skb->data and thus packet header pointers,
don't use stale ip_hdr reference in ip_tunnel code.
17) Backend state transition handling fixes in xen-netback, from Paul
Durrant.
18) Packet offset for AH protocol is handled wrong in flow dissector,
from Eric Dumazet.
19) Taking down an fq packet scheduler instance can leave stale packets
in the queues, fix from Eric Dumazet.
20) Fix performance regressions introduced by TCP Small Queues. From
Eric Dumazet.
21) IPV6 GRE tunneling code calculates max_headroom incorrectly, from
Hannes Frederic Sowa.
22) Multicast timer handlers in ipv4 and ipv6 can be the last and final
reference to the ipv4/ipv6 specific network device state, so use the
reference put that will check and release the object if the
reference hits zero. From Salam Noureddine.
23) Fix memory corruption in ip_tunnel driver, and use skb_push()
instead of __skb_push() so that similar bugs are less hard to find.
From Steffen Klassert.
24) Add forgotten hookup of rtnl_ops in SIT and ip6tnl drivers, from
Nicolas Dichtel.
25) fq scheduler doesn't accurately rate limit in certain circumstances,
from Eric Dumazet.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (103 commits)
pkt_sched: fq: rate limiting improvements
ip6tnl: allow to use rtnl ops on fb tunnel
sit: allow to use rtnl ops on fb tunnel
ip_tunnel: Remove double unregister of the fallback device
ip_tunnel_core: Change __skb_push back to skb_push
ip_tunnel: Add fallback tunnels to the hash lists
ip_tunnel: Fix a memory corruption in ip_tunnel_xmit
qlcnic: Fix SR-IOV configuration
ll_temac: Reset dma descriptors indexes on ndo_open
skbuff: size of hole is wrong in a comment
ipv6 mcast: use in6_dev_put in timer handlers instead of __in6_dev_put
ipv4 igmp: use in_dev_put in timer handlers instead of __in_dev_put
ethernet: moxa: fix incorrect placement of __initdata tag
ipv6: gre: correct calculation of max_headroom
powerpc/83xx: gianfar_ptp: select 1588 clock source through dts file
Revert "powerpc/83xx: gianfar_ptp: select 1588 clock source through dts file"
bonding: Fix broken promiscuity reference counting issue
tcp: TSQ can use a dynamic limit
dm9601: fix IFF_ALLMULTI handling
pkt_sched: fq: qdisc dismantle fixes
...
Make use of arch_mutex_cpu_relax() so architectures can override the
default cpu_relax() semantics.
This is especially useful for s390, where cpu_relax() means that we
yield() the current (virtual) cpu and therefore is very expensive,
and would contradict the whole purpose of the lockless cmpxchg loop.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
In kobj_ns_current_may_mount the default should be to allow the mount.
The test is only for a single kobj_ns_type at a time, and unless there
is a reason to prevent it the mounting sysfs should be allowed.
Subsystems that are not registered can't have are not involved so can't
have a reason to prevent mounting sysfs.
This is a bug-fix to commit 7dc5dbc879 ("sysfs: Restrict mounting
sysfs") that came in via the userns tree during the 3.12 merge window.
Reported-and-tested-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The 64-bit cmpxchg operation on the lockref is ordered by virtue of
hazarding between the cmpxchg operation and the reference count
manipulation. On weakly ordered memory architectures (such as ARM), it
can be of great benefit to omit the barrier instructions where they are
not needed.
This patch moves the lockless lockref code over to a cmpxchg64_relaxed
operation, which doesn't provide barrier semantics. If the operation
isn't defined, we simply #define it as the usual 64-bit cmpxchg macro.
Cc: Waiman Long <Waiman.Long@hp.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
To be able to use the hex ascii functions in case sensitive environments
the array hex_asc_upper[] and the needed functions for hex_byte_pack_upper()
are introduced.
Signed-off-by: Andre Naujoks <nautsch2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The cmpxchg() function tends not to support 64-bit arguments on 32-bit
architectures. This could be either due to use of unsigned long
arguments (like on ARM) or lack of instruction support (cmpxchgq on
x86). However, these architectures may implement a specific cmpxchg64()
function to provide 64-bit cmpxchg support instead.
Since the lockref code requires a 64-bit cmpxchg and relies on the
architecture selecting ARCH_USE_CMPXCHG_LOCKREF, move to using cmpxchg64
instead of cmpxchg and allow 32-bit architectures to make use of the
lockless lockref implementation.
Cc: Waiman Long <Waiman.Long@hp.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull generic hardirq option removal from Martin Schwidefsky:
"All architectures now use generic hardirqs, s390 has been last to
switch.
With that the code under !CONFIG_GENERIC_HARDIRQS and the related
HAVE_GENERIC_HARDIRQS and GENERIC_HARDIRQS config options can be
removed. Yay!"
* 'genirq' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
Remove GENERIC_HARDIRQ config option
Pull crypto fixes from Herbert Xu:
"This fixes a 7+ year race condition in the crypto API that causes
sporadic crashes when multiple threads load the same algorithm.
It also fixes the crct10dif algorithm again to prevent boot failures
on systems where the initramfs tool ignores module softdeps"
* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
crypto: crct10dif - Add fallback for broken initrds
crypto: api - Fix race condition in larval lookup
After the last architecture switched to generic hard irqs the config
options HAVE_GENERIC_HARDIRQS & GENERIC_HARDIRQS and the related code
for !CONFIG_GENERIC_HARDIRQS can be removed.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Pull SCSI target updates from Nicholas Bellinger:
"Lots of activity again this round for I/O performance optimizations
(per-cpu IDA pre-allocation for vhost + iscsi/target), and the
addition of new fabric independent features to target-core
(COMPARE_AND_WRITE + EXTENDED_COPY).
The main highlights include:
- Support for iscsi-target login multiplexing across individual
network portals
- Generic Per-cpu IDA logic (kent + akpm + clameter)
- Conversion of vhost to use per-cpu IDA pre-allocation for
descriptors, SGLs and userspace page pointer list
- Conversion of iscsi-target + iser-target to use per-cpu IDA
pre-allocation for descriptors
- Add support for generic COMPARE_AND_WRITE (AtomicTestandSet)
emulation for virtual backend drivers
- Add support for generic EXTENDED_COPY (CopyOffload) emulation for
virtual backend drivers.
- Add support for fast memory registration mode to iser-target (Vu)
The patches to add COMPARE_AND_WRITE and EXTENDED_COPY support are of
particular significance, which make us the first and only open source
target to support the full set of VAAI primitives.
Currently Linux clients are lacking upstream support to actually
utilize these primitives. However, with server side support now in
place for folks like MKP + ZAB working on the client, this logic once
reserved for the highest end of storage arrays, can now be run in VMs
on their laptops"
* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: (50 commits)
target/iscsi: Bump versions to v4.1.0
target: Update copyright ownership/year information to 2013
iscsi-target: Bump default TCP listen backlog to 256
target: Fix >= v3.9+ regression in PR APTPL + ALUA metadata write-out
iscsi-target; Bump default CmdSN Depth to 64
iscsi-target: Remove unnecessary wait_for_completion in iscsi_get_thread_set
iscsi-target: Add thread_set->ts_activate_sem + use common deallocate
iscsi-target: Fix race with thread_pre_handler flush_signals + ISCSI_THREAD_SET_DIE
target: remove unused including <linux/version.h>
iser-target: introduce fast memory registration mode (FRWR)
iser-target: generalize rdma memory registration and cleanup
iser-target: move rdma wr processing to a shared function
target: Enable global EXTENDED_COPY setup/release
target: Add Third Party Copy (3PC) bit in INQUIRY response
target: Enable EXTENDED_COPY setup in spc_parse_cdb
target: Add support for EXTENDED_COPY copy offload emulation
target: Avoid non-existent tg_pt_gp_mem in target_alua_state_check
target: Add global device list for EXTENDED_COPY
target: Make helpers non static for EXTENDED_COPY command setup
target: Make spc_parse_naa_6h_vendor_specific non static
...
Unfortunately, even with a softdep some distros fail to include
the necessary modules in the initrd. Therefore this patch adds
a fallback path to restore existing behaviour where we cannot
load the new crypto crct10dif algorithm.
In order to do this, the underlying crct10dif has been split out
from the crypto implementation so that it can be used on the
fallback path.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
With users of radix_tree_preload() run from interrupt (block/blk-ioc.c is
one such possible user), the following race can happen:
radix_tree_preload()
...
radix_tree_insert()
radix_tree_node_alloc()
if (rtp->nr) {
ret = rtp->nodes[rtp->nr - 1];
<interrupt>
...
radix_tree_preload()
...
radix_tree_insert()
radix_tree_node_alloc()
if (rtp->nr) {
ret = rtp->nodes[rtp->nr - 1];
And we give out one radix tree node twice. That clearly results in radix
tree corruption with different results (usually OOPS) depending on which
two users of radix tree race.
We fix the problem by making radix_tree_node_alloc() always allocate fresh
radix tree nodes when in interrupt. Using preloading when in interrupt
doesn't make sense since all the allocations have to be atomic anyway and
we cannot steal nodes from process-context users because some users rely
on radix_tree_insert() succeeding after radix_tree_preload().
in_interrupt() check is somewhat ugly but we cannot simply key off passed
gfp_mask as that is acquired from root_gfp_mask() and thus the same for
all preload users.
Another part of the fix is to avoid node preallocation in
radix_tree_preload() when passed gfp_mask doesn't allow waiting. Again,
preallocation in such case doesn't make sense and when preallocation would
happen in interrupt we could possibly leak some allocated nodes. However,
some users of radix_tree_preload() require following radix_tree_insert()
to succeed. To avoid unexpected effects for these users,
radix_tree_preload() only warns if passed gfp mask doesn't allow waiting
and we provide a new function radix_tree_maybe_preload() for those users
which get different gfp mask from different call sites and which are
prepared to handle radix_tree_insert() failure.
Signed-off-by: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <jaxboe@fusionio.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Postorder iteration yields all of a node's children prior to yielding the
node itself, and this particular implementation also avoids examining the
leaf links in a node after that node has been yielded.
In what I expect will be its most common usage, postorder iteration allows
the deletion of every node in an rbtree without modifying the rbtree nodes
(no _requirement_ that they be nulled) while avoiding referencing child
nodes after they have been "deleted" (most commonly, freed).
I have only updated zswap to use this functionality at this point, but
numerous bits of code (most notably in the filesystem drivers) use a hand
rolled postorder iteration that NULLs child links as it traverses the
tree. Each of those instances could be replaced with this common
implementation.
1 & 2 add rbtree postorder iteration functions.
3 adds testing of the iteration to the rbtree runtime tests
4 allows building the rbtree runtime tests as builtins
5 updates zswap.
This patch:
Add postorder iteration functions for rbtree. These are useful for safely
freeing an entire rbtree without modifying the tree at all.
Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com>
Reviewed-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Cc: David Woodhouse <David.Woodhouse@intel.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Michel Lespinasse <walken@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When decompressing into memory, the output buffer length is set to some
arbitrarily high value (0x7fffffff) to indicate the output is, virtually,
unlimited in size.
The problem with this is that some platforms have their physical memory at
high physical addresses (0x80000000 or more), and that the output buffer
address and its "unlimited" length cannot be added without overflowing.
An example of this can be found in inflate_fast():
/* next_out is the output buffer address */
out = strm->next_out - OFF;
/* avail_out is the output buffer size. end will overflow if the output
* address is >= 0x80000104 */
end = out + (strm->avail_out - 257);
This has huge consequences on the performance of kernel decompression,
since the following exit condition of inflate_fast() will be always true:
} while (in < last && out < end);
Indeed, "end" has overflowed and is now always lower than "out". As a
result, inflate_fast() will return after processing one single byte of
input data, and will thus need to be called an unreasonably high number of
times. This probably went unnoticed because kernel decompression is fast
enough even with this issue.
Nonetheless, adjusting the output buffer length in such a way that the
above pointer arithmetic never overflows results in a kernel decompression
that is about 3 times faster on affected machines.
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Tested-by: Jon Medhurst <tixy@linaro.org>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The documentation mentions a "name" parameter, which does not exist. This
commit removes such mention from the function documentation.
Signed-off-by: Emilio López <emilio@elopez.com.ar>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
