On small systems, in the absence of readers, expedited SRCU grace
periods can complete in less than a microsecond. This means that an
eight-CPU system can have all CPUs doing synchronize_srcu() in a tight
loop and almost always expedite. This might actually be desirable in
some situations, but in general it is a good way to needlessly burn
CPU cycles. And in those situations where it is desirable, your friend
is the function synchronize_srcu_expedited().
For other situations, this commit adds a kernel parameter that specifies
a holdoff between completing the last SRCU grace period and auto-expediting
the next. If the next grace period starts before the holdoff expires,
auto-expediting is disabled. The holdoff is 50 microseconds by default,
and can be tuned to the desired number of nanoseconds. A value of zero
disables auto-expediting.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Mike Galbraith <efault@gmx.de>
Classic SRCU in effect expedites the first synchronize_srcu() when SRCU
is idle, and Mike Galbraith demonstrated that some use cases do in fact
rely on this behavior. In particular, Mike showed that Steven Rostedt's
hotplug stress script takes 55 seconds with Classic SRCU and more than
16 -minutes- when running Tree SRCU. Assuming that each Tree SRCU's call
to synchronize_srcu() takes four milliseconds, this implies that Steven's
test invokes synchronize_srcu() in isolation, but more than once per
200 microseconds. Mike used ftrace to demonstrate that the time between
successive calls to synchronize_srcu() ranged from 118 to 342 microseconds,
with one outlier at 80 milliseconds. This data clearly indicates that
Tree SRCU needs to expedite the first invocation of synchronize_srcu()
during an SRCU idle period.
This commit therefor introduces a srcu_might_be_idle() function that
probabilistically checks whether or not SRCU is idle. This function is
used by synchronize_rcu() as an additional criterion in deciding whether
or not to expedite.
(Hat trick to Peter Zijlstra for his earlier suggestion that this might
in fact be a problem. Which for all I know might have motivated Mike to
look into it.)
Reported-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Mike Galbraith <efault@gmx.de>
Commit f60d231a87 ("srcu: Crude control of expedited grace periods")
introduced a per-srcu_struct atomic counter to track outstanding
requests for grace periods. This works, but represents a memory-contention
bottleneck. This commit therefore uses the srcu_node combining tree
to remove this bottleneck.
This commit adds new ->srcu_gp_seq_needed_exp fields to the
srcu_data, srcu_node, and srcu_struct structures, which track the
farthest-in-the-future grace period that must be expedited, which in
turn requires that all nearer-term grace periods also be expedited.
Requests for expediting start with the srcu_data structure, run up
through the srcu_node tree, and end at the srcu_struct structure.
Note that it may be necessary to expedite a grace period that just
now started, and this is handled by a new srcu_funnel_exp_start()
function, which is invoked when the grace period itself is already
in its way, but when that grace period was not marked as expedited.
A new srcu_get_delay() function returns zero if there is at least one
expedited SRCU grace period in flight, or SRCU_INTERVAL otherwise.
This function is used to calculate delays: Normal grace periods
are allowed to extend in order to cover more requests with a given
grace-period computation, which decreases per-request overhead.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Mike Galbraith <efault@gmx.de>
In the past, SRCU was simple enough that there was little point in
making the rcutorture writer stall messages print the SRCU grace-period
number state. With the advent of Tree SRCU, this has changed. This
commit therefore makes Classic, Tiny, and Tree SRCU report this state
to rcutorture as needed.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Mike Galbraith <efault@gmx.de>
The current Tree SRCU implementation schedules a workqueue for every
srcu_data covered by a given leaf srcu_node structure having callbacks,
even if only one of those srcu_data structures actually contains
callbacks. This is clearly inefficient for workloads that don't feature
callbacks everywhere all the time. This commit therefore adds an array
of masks that are used by the leaf srcu_node structures to track exactly
which srcu_data structures contain callbacks.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Mike Galbraith <efault@gmx.de>
SRCU is optional, and included only if there is a "select SRCU" in effect.
However, we now have Tiny SRCU, so this commit defaults CONFIG_SRCU=y.
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
If the CONFIG_SRCU option is not selected, for example, when building
arch/tile allnoconfig, the following build errors appear:
kernel/rcu/tree.o: In function `srcu_online_cpu':
tree.c:(.text+0x4248): multiple definition of `srcu_online_cpu'
kernel/rcu/srcutree.o:srcutree.c:(.text+0x2120): first defined here
kernel/rcu/tree.o: In function `srcu_offline_cpu':
tree.c:(.text+0x4250): multiple definition of `srcu_offline_cpu'
kernel/rcu/srcutree.o:srcutree.c:(.text+0x2160): first defined here
The corresponding .config file shows CONFIG_TREE_SRCU=y, but no sign
of CONFIG_SRCU, which fatally confuses SRCU's #ifdefs, resulting in
the above errors. The reason this occurs is the folowing line in
init/Kconfig's definition for TREE_SRCU:
default y if !TINY_RCU && !CLASSIC_SRCU
If CONFIG_CLASSIC_SRCU=n, as it will be in for allnoconfig, and if
CONFIG_SMP=y, then we will get CONFIG_TREE_SRCU=y but no CONFIG_SRCU,
as seen in the .config file, and which will result in the above errors.
This error did not show up during rcutorture testing because rcutorture
forces CONFIG_SRCU=y, as it must to prevent build errors in rcutorture.c.
This commit therefore conditions TREE_SRCU (and TINY_SRCU, while it is
at it) with SRCU, like this:
default y if SRCU && !TINY_RCU && !CLASSIC_SRCU
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/20170423162205.GP3956@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
unsupported NFSv4 compound op.
-----BEGIN PGP SIGNATURE-----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=mSBF
-----END PGP SIGNATURE-----
Merge tag 'nfsd-4.11-2' of git://linux-nfs.org/~bfields/linux
Pull nfsd bugfix from Bruce Fields:
"Fix a 4.11 regression that triggers a BUG() on an attempt to use an
unsupported NFSv4 compound op"
* tag 'nfsd-4.11-2' of git://linux-nfs.org/~bfields/linux:
nfsd: fix oops on unsupported operation
Pull networking fixes from David Miller:
1) Don't race in IPSEC dumps, from Yuejie Shi.
2) Verify lengths properly in IPSEC reqeusts, from Herbert Xu.
3) Fix out of bounds access in ipv6 segment routing code, from David
Lebrun.
4) Don't write into the header of cloned SKBs in smsc95xx driver, from
James Hughes.
5) Several other drivers have this bug too, fix them. From Eric
Dumazet.
6) Fix access to uninitialized data in TC action cookie code, from
Wolfgang Bumiller.
7) Fix double free in IPV6 segment routing, again from David Lebrun.
8) Don't let userspace set the RTF_PCPU flag, oops. From David Ahern.
9) Fix use after free in qrtr code, from Dan Carpenter.
10) Don't double-destroy devices in ip6mr code, from Nikolay
Aleksandrov.
11) Don't pass out-of-range TX queue indices into drivers, from Tushar
Dave.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (30 commits)
netpoll: Check for skb->queue_mapping
ip6mr: fix notification device destruction
bpf, doc: update bpf maintainers entry
net: qrtr: potential use after free in qrtr_sendmsg()
bpf: Fix values type used in test_maps
net: ipv6: RTF_PCPU should not be settable from userspace
gso: Validate assumption of frag_list segementation
kaweth: use skb_cow_head() to deal with cloned skbs
ch9200: use skb_cow_head() to deal with cloned skbs
lan78xx: use skb_cow_head() to deal with cloned skbs
sr9700: use skb_cow_head() to deal with cloned skbs
cx82310_eth: use skb_cow_head() to deal with cloned skbs
smsc75xx: use skb_cow_head() to deal with cloned skbs
ipv6: sr: fix double free of skb after handling invalid SRH
MAINTAINERS: Add "B:" field for networking.
net sched actions: allocate act cookie early
qed: Fix issue in populating the PFC config paramters.
qed: Fix possible system hang in the dcbnl-getdcbx() path.
qed: Fix sending an invalid PFC error mask to MFW.
qed: Fix possible error in populating max_tc field.
...
Add various related files that have been missing under
BPF entry covering essential parts of its infrastructure
and also add myself as co-maintainer.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
If skb_pad() fails then it frees the skb so we should check for errors.
Fixes: bdabad3e36 ("net: Add Qualcomm IPC router")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Maps of per-cpu type have their value element size adjusted to 8 if it
is specified smaller during various map operations.
This makes test_maps as a 32-bit binary fail, in fact the kernel
writes past the end of the value's array on the user's stack.
To be quite honest, I think the kernel should reject creation of a
per-cpu map that doesn't have a value size of at least 8 if that's
what the kernel is going to silently adjust to later.
If the user passed something smaller, it is a sizeof() calcualtion
based upon the type they will actually use (just like in this testcase
code) in later calls to the map operations.
Fixes: df570f5772 ("samples/bpf: unit test for BPF_MAP_TYPE_PERCPU_ARRAY")
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Andrey reported a fault in the IPv6 route code:
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] SMP KASAN
Modules linked in:
CPU: 1 PID: 4035 Comm: a.out Not tainted 4.11.0-rc7+ #250
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
task: ffff880069809600 task.stack: ffff880062dc8000
RIP: 0010:ip6_rt_cache_alloc+0xa6/0x560 net/ipv6/route.c:975
RSP: 0018:ffff880062dced30 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: ffff8800670561c0 RCX: 0000000000000006
RDX: 0000000000000003 RSI: ffff880062dcfb28 RDI: 0000000000000018
RBP: ffff880062dced68 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: ffff880062dcfb28 R14: dffffc0000000000 R15: 0000000000000000
FS: 00007feebe37e7c0(0000) GS:ffff88006cb00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000205a0fe4 CR3: 000000006b5c9000 CR4: 00000000000006e0
Call Trace:
ip6_pol_route+0x1512/0x1f20 net/ipv6/route.c:1128
ip6_pol_route_output+0x4c/0x60 net/ipv6/route.c:1212
...
Andrey's syzkaller program passes rtmsg.rtmsg_flags with the RTF_PCPU bit
set. Flags passed to the kernel are blindly copied to the allocated
rt6_info by ip6_route_info_create making a newly inserted route appear
as though it is a per-cpu route. ip6_rt_cache_alloc sees the flag set
and expects rt->dst.from to be set - which it is not since it is not
really a per-cpu copy. The subsequent call to __ip6_dst_alloc then
generates the fault.
Fix by checking for the flag and failing with EINVAL.
Fixes: d52d3997f8 ("ipv6: Create percpu rt6_info")
Reported-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Tested-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit 07b26c9454 ("gso: Support partial splitting at the frag_list
pointer") assumes that all SKBs in a frag_list (except maybe the last
one) contain the same amount of GSO payload.
This assumption is not always correct, resulting in the following
warning message in the log:
skb_segment: too many frags
For example, mlx5 driver in Striding RQ mode creates some RX SKBs with
one frag, and some with 2 frags.
After GRO, the frag_list SKBs end up having different amounts of payload.
If this frag_list SKB is then forwarded, the aforementioned assumption
is violated.
Validate the assumption, and fall back to software GSO if it not true.
Change-Id: Ia03983f4a47b6534dd987d7a2aad96d54d46d212
Fixes: 07b26c9454 ("gso: Support partial splitting at the frag_list pointer")
Signed-off-by: Ilan Tayari <ilant@mellanox.com>
Signed-off-by: Ilya Lesokhin <ilyal@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Eric Dumazet says:
====================
net: use skb_cow_head() to deal with cloned skbs
James Hughes found an issue with smsc95xx driver. Same problematic code
is found in other drivers.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
We can use skb_cow_head() to properly deal with clones,
especially the ones coming from TCP stack that allow their head being
modified. This avoids a copy.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: James Hughes <james.hughes@raspberrypi.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
We need to ensure there is enough headroom to push extra header,
but we also need to check if we are allowed to change headers.
skb_cow_head() is the proper helper to deal with this.
Fixes: 4a476bd6d1 ("usbnet: New driver for QinHeng CH9200 devices")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: James Hughes <james.hughes@raspberrypi.org>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
We need to ensure there is enough headroom to push extra header,
but we also need to check if we are allowed to change headers.
skb_cow_head() is the proper helper to deal with this.
Fixes: 55d7de9de6 ("Microchip's LAN7800 family USB 2/3 to 10/100/1000 Ethernet device driver")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: James Hughes <james.hughes@raspberrypi.org>
Cc: Woojung Huh <woojung.huh@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We need to ensure there is enough headroom to push extra header,
but we also need to check if we are allowed to change headers.
skb_cow_head() is the proper helper to deal with this.
Fixes: c9b37458e9 ("USB2NET : SR9700 : One chip USB 1.1 USB2NET SR9700Device Driver Support")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: James Hughes <james.hughes@raspberrypi.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
We need to ensure there is enough headroom to push extra header,
but we also need to check if we are allowed to change headers.
skb_cow_head() is the proper helper to deal with this.
Fixes: cc28a20e77 ("introduce cx82310_eth: Conexant CX82310-based ADSL router USB ethernet driver")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: James Hughes <james.hughes@raspberrypi.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
We need to ensure there is enough headroom to push extra header,
but we also need to check if we are allowed to change headers.
skb_cow_head() is the proper helper to deal with this.
Fixes: d0cad87170 ("smsc75xx: SMSC LAN75xx USB gigabit ethernet adapter driver")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: James Hughes <james.hughes@raspberrypi.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The icmpv6_param_prob() function already does a kfree_skb(),
this patch removes the duplicate one.
Fixes: 1ababeba4a ("ipv6: implement dataplane support for rthdr type 4 (Segment Routing Header)")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David Lebrun <david.lebrun@uclouvain.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
Just two fixes. The first fixes kprobing a stdu, and is marked for stable as
it's been broken for ~ever. In hindsight this could have gone in next.
The other is a fix for a change we merged this cycle, where if we take a certain
exception when the kernel is running relocated (currently only used for kdump),
we checkstop the box.
Thanks to:
Ravi Bangoria.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1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=yUj5
-----END PGP SIGNATURE-----
Merge tag 'powerpc-4.11-8' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc fixes from Michael Ellerman:
"Just two fixes.
The first fixes kprobing a stdu, and is marked for stable as it's been
broken for ~ever. In hindsight this could have gone in next.
The other is a fix for a change we merged this cycle, where if we take
a certain exception when the kernel is running relocated (currently
only used for kdump), we checkstop the box.
Thanks to Ravi Bangoria"
* tag 'powerpc-4.11-8' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc/64: Fix HMI exception on LE with CONFIG_RELOCATABLE=y
powerpc/kprobe: Fix oops when kprobed on 'stdu' instruction
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1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=qqfj
-----END PGP SIGNATURE-----
Merge tag 'pci-v4.11-fixes-5' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci
Pull PCI fix from Bjorn Helgaas:
"Sorry this is so late. It's been in -next for over a week, but I
forgot to send it on until now.
A single fix to the DT binding of the HiSilicon PCIe host support"
* tag 'pci-v4.11-fixes-5' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
PCI: hisi: Fix DT binding (hisi-pcie-almost-ecam)
Pull block layer fixes from Jens Axboe:
"A couple of last minute fixes for regressions in this cycle. More
specifically:
- Two patches from Andy, adjusting the NVMe APST quirks to avoid some
issues specific to one Toshiba drive, and some variant of Samsung
on two specific Dell laptops.
- A fix for mtip32xx, turning off mq scheduling on that device. We
have a real fix for this, but it's too late in the cycle.
Thankfully we already have a NO_SCHED flag we can apply here. A
prep patch for this is ensuring that we honor the NO_SCHED flag
when attempting to online switch schedulers, previsouly we only did
so for drive load time. From Ming.
- Fixing an oops in blk-mq polling with scheduling attached. This one
is easily reproducible, it would be a shame to release 4.11 with
that issue. From me.
I'd prefer not having to send in patches at this point in time, but
the above are all things that have regressed in this cycle and the
fixes are relatively straight forward"
* 'for-linus' of git://git.kernel.dk/linux-block:
blk-mq: fix potential oops with polling and blk-mq scheduler
nvme: Quirk APST off on "THNSF5256GPUK TOSHIBA"
nvme: Adjust the Samsung APST quirk
mtip32xx: pass BLK_MQ_F_NO_SCHED
block: respect BLK_MQ_F_NO_SCHED
- Avoid a false-positive warning regarding a variable that may not
be initialized that started to trigger after a previous general
build fix (Arnd Bergmann).
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2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=W+qr
-----END PGP SIGNATURE-----
Merge tag 'acpi-4.11-final' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull ACPI build fix from Rafael Wysocki:
"This avoids a false-positive build warning from the compiler.
Specifics:
- Avoid a false-positive warning regarding a variable that may not be
initialized that started to trigger after a previous general build
fix (Arnd Bergmann)"
* tag 'acpi-4.11-final' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
ACPI / power: Avoid maybe-uninitialized warning
- kmalloc sdio scratch buffer to make it DMA-friendly
MMC host:
- dw_mmc: Fix behaviour for SDIO IRQs when runtime PM is used
- sdhci-esdhc-imx: Correct pad I/O drive strength for UHS-DDR50 cards
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1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=XYxi
-----END PGP SIGNATURE-----
Merge tag 'mmc-v4.11-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc
Pull MMC fixes from Ulf Hansson:
"MMC core:
- kmalloc sdio scratch buffer to make it DMA-friendly
MMC host:
- dw_mmc: Fix behaviour for SDIO IRQs when runtime PM is used
- sdhci-esdhc-imx: Correct pad I/O drive strength for UHS-DDR50
cards"
* tag 'mmc-v4.11-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc:
mmc: sdhci-esdhc-imx: increase the pad I/O drive strength for DDR50 card
mmc: dw_mmc: Don't allow Runtime PM for SDIO cards
mmc: sdio: fix alignment issue in struct sdio_func
Pull input fixlet from Dmitry Torokhov:
"An update to Elan PS/2 driver to allow working on yet another
Lifebook"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
Input: elantech - add Fujitsu Lifebook E547 to force crc_enabled
Currently, a call to schedule() acts as a Tasks RCU quiescent state
only if a context switch actually takes place. However, just the
call to schedule() guarantees that the calling task has moved off of
whatever tracing trampoline that it might have been one previously.
This commit therefore plumbs schedule()'s "preempt" parameter into
rcu_note_context_switch(), which then records the Tasks RCU quiescent
state, but only if this call to schedule() was -not- due to a preemption.
To avoid adding overhead to the common-case context-switch path,
this commit hides the rcu_note_context_switch() check under an existing
non-common-case check.
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Although Tree SRCU does reduce delays when there is at least one
synchronize_srcu_expedited() invocation pending, srcu_schedule_cbs_snp()
still waits for SRCU_INTERVAL before invoking callbacks. Since
synchronize_srcu_expedited() now posts a callback and waits for
that callback to do a wakeup, this destroys the expedited nature of
synchronize_srcu_expedited(). This destruction became apparent to
Marc Zyngier in the guise of a guest-OS bootup slowdown from five
seconds to no fewer than forty seconds.
This commit therefore invokes callbacks immediately at the end of the
grace period when there is at least one synchronize_srcu_expedited()
invocation pending. This brought Marc's guest-OS bootup times back
into the realm of reason.
Reported-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Marc Zyngier <marc.zyngier@arm.com>
Peter Zijlstra proposed using SRCU to reduce mmap_sem contention [1,2],
however, there are workloads that could result in a high volume of
concurrent invocations of call_srcu(), which with current SRCU would
result in excessive lock contention on the srcu_struct structure's
->queue_lock, which protects SRCU's callback lists. This commit therefore
moves SRCU to per-CPU callback lists, thus greatly reducing contention.
Because a given SRCU instance no longer has a single centralized callback
list, starting grace periods and invoking callbacks are both more complex
than in the single-list Classic SRCU implementation. Starting grace
periods and handling callbacks are now handled using an srcu_node tree
that is in some ways similar to the rcu_node trees used by RCU-bh,
RCU-preempt, and RCU-sched (for example, the srcu_node tree shape is
controlled by exactly the same Kconfig options and boot parameters that
control the shape of the rcu_node tree).
In addition, the old per-CPU srcu_array structure is now named srcu_data
and contains an rcu_segcblist structure named ->srcu_cblist for its
callbacks (and a spinlock to protect this). The srcu_struct gets
an srcu_gp_seq that is used to associate callback segments with the
corresponding completion-time grace-period number. These completion-time
grace-period numbers are propagated up the srcu_node tree so that the
grace-period workqueue handler can determine whether additional grace
periods are needed on the one hand and where to look for callbacks that
are ready to be invoked.
The srcu_barrier() function must now wait on all instances of the per-CPU
->srcu_cblist. Because each ->srcu_cblist is protected by ->lock,
srcu_barrier() can remotely add the needed callbacks. In theory,
it could also remotely start grace periods, but in practice doing so
is complex and racy. And interestingly enough, it is never necessary
for srcu_barrier() to start a grace period because srcu_barrier() only
enqueues a callback when a callback is already present--and it turns out
that a grace period has to have already been started for this pre-existing
callback. Furthermore, it is only the callback that srcu_barrier()
needs to wait on, not any particular grace period. Therefore, a new
rcu_segcblist_entrain() function enqueues the srcu_barrier() function's
callback into the same segment occupied by the last pre-existing callback
in the list. The special case where all the pre-existing callbacks are
on a different list (because they are in the process of being invoked)
is handled by enqueuing srcu_barrier()'s callback into the RCU_DONE_TAIL
segment, relying on the done-callbacks check that takes place after all
callbacks are inovked.
Note that the readers use the same algorithm as before. Note that there
is a separate srcu_idx that tells the readers what counter to increment.
This unfortunately cannot be combined with srcu_gp_seq because they
need to be incremented at different times.
This commit introduces some ugly #ifdefs in rcutorture. These will go
away when I feel good enough about Tree SRCU to ditch Classic SRCU.
Some crude performance comparisons, courtesy of a quickly hacked rcuperf
asynchronous-grace-period capability:
Callback Queuing Overhead
-------------------------
# CPUS Classic SRCU Tree SRCU
------ ------------ ---------
2 0.349 us 0.342 us
16 31.66 us 0.4 us
41 --------- 0.417 us
The times are the 90th percentiles, a statistic that was chosen to reject
the overheads of the occasional srcu_barrier() call needed to avoid OOMing
the test machine. The rcuperf test hangs when running Classic SRCU at 41
CPUs, hence the line of dashes. Despite the hacks to both the rcuperf code
and that statistics, this is a convincing demonstration of Tree SRCU's
performance and scalability advantages.
[1] https://lwn.net/Articles/309030/
[2] https://patchwork.kernel.org/patch/5108281/
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
[ paulmck: Fix initialization if synchronize_srcu_expedited() called first. ]
Parallelizing SRCU callback handling will increase the size of
srcu_struct, which will move the kvm structure's kvm_arch field out
of reach of powerpc's current assembly code, which will result in the
following sort of build error:
arch/powerpc/kvm/book3s_hv_rmhandlers.S:617: Error: operand out of range (0x000000000000b328 is not between 0xffffffffffff8000 and 0x0000000000007fff)
This commit moves the srcu_struct fields in the kvm structure to follow
the kvm_arch field, which will allow powerpc's assembly code to continue
to be able to reach the kvm_arch field.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reported-by: Michael Ellerman <michaele@au1.ibm.com>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
[ paulmck: Moved this commit to precede SRCU callback parallelization,
and reworded the commit log into future tense, all in the name of
bisectability. ]
Merge two mm fixes from Andrew Morton.
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
mm: prevent NR_ISOLATE_* stats from going negative
Revert "mm, page_alloc: only use per-cpu allocator for irq-safe requests"
Commit 6afcf8ef0c ("mm, compaction: fix NR_ISOLATED_* stats for pfn
based migration") moved the dec_node_page_state() call (along with the
page_is_file_cache() call) to after putback_lru_page().
But page_is_file_cache() can change after putback_lru_page() is called,
so it should be called before putback_lru_page(), as it was before that
patch, to prevent NR_ISOLATE_* stats from going negative.
Without this fix, non-CONFIG_SMP kernels end up hanging in the
while(too_many_isolated()) { congestion_wait() } loop in
shrink_active_list() due to the negative stats.
Mem-Info:
active_anon:32567 inactive_anon:121 isolated_anon:1
active_file:6066 inactive_file:6639 isolated_file:4294967295
^^^^^^^^^^
unevictable:0 dirty:115 writeback:0 unstable:0
slab_reclaimable:2086 slab_unreclaimable:3167
mapped:3398 shmem:18366 pagetables:1145 bounce:0
free:1798 free_pcp:13 free_cma:0
Fixes: 6afcf8ef0c ("mm, compaction: fix NR_ISOLATED_* stats for pfn based migration")
Link: http://lkml.kernel.org/r/1492683865-27549-1-git-send-email-rabin.vincent@axis.com
Signed-off-by: Rabin Vincent <rabinv@axis.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Ming Ling <ming.ling@spreadtrum.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This reverts commit 374ad05ab6.
While the patch worked great for userspace allocations, the fact that
softirq loses the per-cpu allocator caused problems. It needs to be
redone taking into account that a separate list is needed for hard/soft
IRQs or alternatively find a cheap way of detecting reentry due to an
interrupt. Both are possible but sufficiently tricky that it shouldn't
be rushed.
Jesper had one method for allowing softirqs but reported that the cost
was high enough that it performed similarly to a plain revert. His
figures for netperf TCP_STREAM were as follows
Baseline v4.10.0 : 60316 Mbit/s
Current 4.11.0-rc6: 47491 Mbit/s
Jesper's patch : 60662 Mbit/s
This patch : 60106 Mbit/s
As this is a regression, I wish to revert to noirq allocator for now and
go back to the drawing board.
Link: http://lkml.kernel.org/r/20170415145350.ixy7vtrzdzve57mh@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reported-by: Tariq Toukan <ttoukan.linux@gmail.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If we have a scheduler attached, blk_mq_tag_to_rq() on the
scheduled tags will return NULL if a request is no longer
in flight. This is different than using the normal tags,
where it will always return the fixed request. Check for
this condition for polling, in case we happen to enter
polling for a completed request.
The request address remains valid, so this check and return
should be perfectly safe.
Fixes: bd166ef183 ("blk-mq-sched: add framework for MQ capable IO schedulers")
Tested-by: Stephen Bates <sbates@raithlin.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
There's a report that it malfunctions with APST on.
See https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1678184
Cc: Kai-Heng Feng <kai.heng.feng@canonical.com>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
I got a couple more reports: the Samsung APST issues appears to
affect multiple 950-series devices in Dell XPS 15 9550 and Precision
5510 laptops. Change the quirk: rather than blacklisting the
firmware on the first problematic SSD that was reported, disable
APST on all 144d:a802 devices if they're installed in the two
affected Dell models. While we're at it, disable only the deepest
sleep state instead of all of them -- the reporters say that this is
sufficient to fix the problem.
(I have a device that appears to be entirely identical to one of the
affected devices, but I have a different Dell laptop, so it's not
the case that all Samsung devices with firmware BXW75D0Q are broken
under all circumstances.)
Samsung engineers have an affected system, and hopefully they'll
give us a better workaround some time soon. In the mean time, this
should minimize regressions.
See https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1678184
Cc: Kai-Heng Feng <kai.heng.feng@canonical.com>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
Policing filters do not use the TCA_ACT_* enum and the tb[]
nlattr array in tcf_action_init_1() doesn't get filled for
them so we should not try to look for a TCA_ACT_COOKIE
attribute in the then uninitialized array.
The error handling in cookie allocation then calls
tcf_hash_release() leading to invalid memory access later
on.
Additionally, if cookie allocation fails after an already
existing non-policing filter has successfully been changed,
tcf_action_release() should not be called, also we would
have to roll back the changes in the error handling, so
instead we now allocate the cookie early and assign it on
success at the end.
CVE-2017-7979
Fixes: 1045ba77a5 ("net sched actions: Add support for user cookies")
Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Sudarsana Reddy Kalluru says:
====================
qed: Dcbx bug fixes
The series has set of bug fixes for dcbx implementation of qed driver.
Please consider applying this to 'net' branch.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Change ieee_setpfc() callback implementation to populate traffic class
count with the user provided value.
Signed-off-by: Sudarsana Reddy Kalluru <Sudarsana.Kalluru@cavium.com>
Signed-off-by: Yuval Mintz <Yuval.Mintz@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
qed_dcbnl_get_dcbx() API uses kmalloc in GFT_KERNEL mode. The API gets
invoked in the interrupt context by qed_dcbnl_getdcbx callback. Need
to invoke this kmalloc in atomic mode.
Signed-off-by: Sudarsana Reddy Kalluru <Sudarsana.Kalluru@cavium.com>
Signed-off-by: Yuval Mintz <Yuval.Mintz@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
PFC error-mask value is not supported by MFW, but this bit could be
set in the pfc bit-map of the operational parameters if remote device
supports it. These operational parameters are used as basis for
populating the dcbx config parameters. User provided configs will be
applied on top of these parameters and then send them to MFW when
requested. Driver need to clear the error-mask bit before sending the
config parameters to MFW.
Signed-off-by: Sudarsana Reddy Kalluru <Sudarsana.Kalluru@cavium.com>
Signed-off-by: Yuval Mintz <Yuval.Mintz@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Some adapters may not publish the max_tc value. Populate the default
value for max_tc field in case the mfw didn't provide one.
Signed-off-by: Sudarsana Reddy Kalluru <Sudarsana.Kalluru@cavium.com>
Signed-off-by: Yuval Mintz <Yuval.Mintz@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The driver was failing to check that the SKB wasn't cloned
before adding checksum data.
Replace existing handling to extend/copy the header buffer
with skb_cow_head.
Signed-off-by: James Hughes <james.hughes@raspberrypi.org>
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-by: Woojung Huh <Woojung.Huh@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
