In its <asm/elf.h> ia64 defines SET_PERSONALITY in a way that unconditionally
sets the personality of the current process to PER_LINUX, losing any flag bits
from the upper 3 bytes of current->personality. This is wrong. Those bits are
intended to be inherited across exec (other code takes care of ensuring that
security sensitive bits like ADDR_NO_RANDOMIZE are not passed to unsuspecting
setuid/setgid applications).
Signed-off-by: Tony Luck <tony.luck@intel.com>
__per_cpu_idtrs is statically allocated ... on CONFIG_NR_CPUS=4096
systems it hogs 16MB of memory. This is way too much for a quite
probably unused facility (only KVM uses dynamic TR registers).
Change to an array of pointers, and allocate entries as needed on
a per cpu basis. Change the name too as the __per_cpu_ prefix is
confusing (this isn't a classic <linux/percpu.h> type object).
Signed-off-by: Tony Luck <tony.luck@intel.com>
pcibus_to_node can return -1 if we cannot determine which node a pci bus
is on. If passed -1, cpumask_of_node will negatively index the lookup array
and pull in random data:
# cat /sys/devices/pci0000:00/0000:00:01.0/local_cpus
00000000,00000003,00000000,00000000
# cat /sys/devices/pci0000:00/0000:00:01.0/local_cpulist
64-65
Change cpumask_of_node to check for -1 and return cpu_all_mask in this
case:
# cat /sys/devices/pci0000:00/0000:00:01.0/local_cpus
ffffffff,ffffffff,ffffffff,ffffffff
# cat /sys/devices/pci0000:00/0000:00:01.0/local_cpulist
0-127
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>
The only thing arch-specific about calling _PDC is what bits get
set in the input obj_list buffer.
There's no need for several levels of indirection to twiddle those
bits. Additionally, since we're just messing around with a buffer,
we can simplify the interface; no need to pass around the entire
struct acpi_processor * just to get at the buffer.
Cc: Tony Luck <tony.luck@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>
arch dependent helper function that tells us if we should attempt to
evaluate _PDC on this machine or not.
The x86 implementation assumes that the CPUs in the machine must be
homogeneous, and that you cannot mix CPUs of different vendors.
Cc: Tony Luck <tony.luck@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>
* 'for-33' of git://repo.or.cz/linux-kbuild: (29 commits)
net: fix for utsrelease.h moving to generated
gen_init_cpio: fixed fwrite warning
kbuild: fix make clean after mismerge
kbuild: generate modules.builtin
genksyms: properly consider EXPORT_UNUSED_SYMBOL{,_GPL}()
score: add asm/asm-offsets.h wrapper
unifdef: update to upstream revision 1.190
kbuild: specify absolute paths for cscope
kbuild: create include/generated in silentoldconfig
scripts/package: deb-pkg: use fakeroot if available
scripts/package: add KBUILD_PKG_ROOTCMD variable
scripts/package: tar-pkg: use tar --owner=root
Kbuild: clean up marker
net: add net_tstamp.h to headers_install
kbuild: move utsrelease.h to include/generated
kbuild: move autoconf.h to include/generated
drop explicit include of autoconf.h
kbuild: move compile.h to include/generated
kbuild: drop include/asm
kbuild: do not check for include/asm-$ARCH
...
Fixed non-conflicting clean merge of modpost.c as per comments from
Stephen Rothwell (modpost.c had grown an include of linux/autoconf.h
that needed to be changed to generated/autoconf.h)
* git://git.infradead.org/iommu-2.6:
implement early_io{re,un}map for ia64
Revert "Intel IOMMU: Avoid memory allocation failures in dma map api calls"
intel-iommu: ignore page table validation in pass through mode
intel-iommu: Fix oops with intel_iommu=igfx_off
intel-iommu: Check for an RMRR which ends before it starts.
intel-iommu: Apply BIOS sanity checks for interrupt remapping too.
intel-iommu: Detect DMAR in hyperspace at probe time.
dmar: Fix build failure without NUMA, warn on bogus RHSA tables and don't abort
iommu: Allocate dma-remapping structures using numa locality info
intr_remap: Allocate intr-remapping table using numa locality info
dmar: Allocate queued invalidation structure using numa locality info
dmar: support for parsing Remapping Hardware Static Affinity structure
dma_mask is, when interpreted as address, the last valid byte, and hence
comparison msut also be done using the last valid of the buffer in
question.
Also fix the open-coded instances in lib/swiotlb.c.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Becky Bruce <beckyb@kernel.crashing.org>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently all architectures but microblaze unconditionally define
USE_ELF_CORE_DUMP. The microblaze omission seems like an error to me, so
let's kill this ifdef and make sure we are the same everywhere.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: <linux-arch@vger.kernel.org>
Cc: Michal Simek <michal.simek@petalogix.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Needed for commit 2c992208 ("intel-iommu: Detect DMAR in hyperspace at
probe time.) to build on IA64.
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
* 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (26 commits)
clockevents: Convert to raw_spinlock
clockevents: Make tick_device_lock static
debugobjects: Convert to raw_spinlocks
perf_event: Convert to raw_spinlock
hrtimers: Convert to raw_spinlocks
genirq: Convert irq_desc.lock to raw_spinlock
smp: Convert smplocks to raw_spinlocks
rtmutes: Convert rtmutex.lock to raw_spinlock
sched: Convert pi_lock to raw_spinlock
sched: Convert cpupri lock to raw_spinlock
sched: Convert rt_runtime_lock to raw_spinlock
sched: Convert rq->lock to raw_spinlock
plist: Make plist debugging raw_spinlock aware
bkl: Fixup core_lock fallout
locking: Cleanup the name space completely
locking: Further name space cleanups
alpha: Fix fallout from locking changes
locking: Implement new raw_spinlock
locking: Convert raw_rwlock functions to arch_rwlock
locking: Convert raw_rwlock to arch_rwlock
...
Move definition of NUMA_NO_NODE from ia64 and x86_64 arch specific headers
to generic header 'linux/numa.h' for use in generic code. NUMA_NO_NODE
replaces bare '-1' where it's used in this series to indicate "no node id
specified". Ultimately, it can be used to replace the -1 elsewhere where
it is used similarly.
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Andi Kleen <andi@firstfloor.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Nishanth Aravamudan <nacc@us.ibm.com>
Cc: Adam Litke <agl@us.ibm.com>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: Eric Whitney <eric.whitney@hp.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
SPIN_LOCK_UNLOCKED is deprecated. Use __SPIN_LOCK_UNLOCKED instead.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-ia64@vger.kernel.org
Signed-off-by: Tony Luck <tony.luck@intel.com>
This is a patch related to this discussion.
http://www.spinics.net/lists/linux-ia64/msg07605.html
When INIT is sent, ip/psr/pfs register is stored to the I-resources
(iip/ipsr/ifs registers), and they are copied in the min-state save
area(pmsa_{iip,ipsr,ifs}).
Therefore, in creating pt_regs at ia64_mca_modify_original_stack(),
cr_{iip,ipsr,ifs} should be derived from pmsa_{iip,ipsr,ifs}. But
current code copies pmsa_{xip,xpsr,xfs} to cr_{iip,ipsr,ifs}
when PSR.ic is 0.
finish_pt_regs(struct pt_regs *regs, const pal_min_state_area_t *ms,
unsigned long *nat)
{
(snip)
if (ia64_psr(regs)->ic) {
regs->cr_iip = ms->pmsa_iip;
regs->cr_ipsr = ms->pmsa_ipsr;
regs->cr_ifs = ms->pmsa_ifs;
} else {
regs->cr_iip = ms->pmsa_xip;
regs->cr_ipsr = ms->pmsa_xpsr;
regs->cr_ifs = ms->pmsa_xfs;
}
It's ok when PSR.ic is not 0. But when PSR.ic is 0, this could be
a problem when we investigate kernel as the value of regs->cr_iip does
not point to where INIT really interrupted.
At first I tried to change finish_pt_regs() so that it uses always
pmsa_{iip,ipsr,ifs} for cr_{iip,ipsr,ifs}, but Keith Owens pointed out
it could cause another problem if I change it.
>The only problem I can think of is an MCA/INIT
>arriving while code like SAVE_MIN or SAVE_REST is executing. Back
>tracing at that point using pmsa_iip is going to be a problem, you have
>no idea what state the registers or stack are in.
I confirmed he was right, so I decided to keep it as-is and to
save pmsa_{iip,ipsr,ifs} to ia64_sal_os_state for debugging.
An attached patch is just adding new members into ia64_sal_os_state to
save pmsa_{iip,ipsr,ifs}.
Signed-off-by: Takao Indoh <indou.takao@jp.fujitsu.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Previously, we tried to use IA64_DEF_FIRST_DEVICE_VECTOR (0x30) as the
IA64_IRQ_MOVE_VECTOR. However, we allocate other IRQs from the device
vector range, so there's no guarantee that IA64_DEF_FIRST_DEVICE_VECTOR
will still be available when we register IA64_IRQ_MOVE_VECTOR.
This patch statically allocates 0x30 for IA64_IRQ_MOVE_VECTOR and
removes it from the device vector range.
Without this patch, we crash on machines like the HP rx3600 that use
vector 48 (0x30) as the ACPI SCI interrupt:
kernel BUG at arch/ia64/kernel/irq_ia64.c:647!
swapper[0]: bugcheck! 0 [1]
Modules linked in:
Pid: 0, CPU 0, comm: swapper
psr : 00001010084a2018 ifs : 800000000000030e ip : [<a000000100012ed0>] Not tainted (2.6.32-rc8-00184-gd5d4ec8)
ip is at ia64_native_register_percpu_irq+0x110/0x1e0
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Tested-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Tested-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Name space cleanup for rwlock functions. No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: linux-arch@vger.kernel.org
Not strictly necessary for -rt as -rt does not have non sleeping
rwlocks, but it's odd to not have a consistent naming convention.
No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: linux-arch@vger.kernel.org
Name space cleanup. No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: linux-arch@vger.kernel.org
Further name space cleanup. No functional change
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: linux-arch@vger.kernel.org
The raw_spin* namespace was taken by lockdep for the architecture
specific implementations. raw_spin_* would be the ideal name space for
the spinlocks which are not converted to sleeping locks in preempt-rt.
Linus suggested to convert the raw_ to arch_ locks and cleanup the
name space instead of using an artifical name like core_spin,
atomic_spin or whatever
No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: linux-arch@vger.kernel.org
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (34 commits)
m68k: rename global variable vmalloc_end to m68k_vmalloc_end
percpu: add missing per_cpu_ptr_to_phys() definition for UP
percpu: Fix kdump failure if booted with percpu_alloc=page
percpu: make misc percpu symbols unique
percpu: make percpu symbols in ia64 unique
percpu: make percpu symbols in powerpc unique
percpu: make percpu symbols in x86 unique
percpu: make percpu symbols in xen unique
percpu: make percpu symbols in cpufreq unique
percpu: make percpu symbols in oprofile unique
percpu: make percpu symbols in tracer unique
percpu: make percpu symbols under kernel/ and mm/ unique
percpu: remove some sparse warnings
percpu: make alloc_percpu() handle array types
vmalloc: fix use of non-existent percpu variable in put_cpu_var()
this_cpu: Use this_cpu_xx in trace_functions_graph.c
this_cpu: Use this_cpu_xx for ftrace
this_cpu: Use this_cpu_xx in nmi handling
this_cpu: Use this_cpu operations in RCU
this_cpu: Use this_cpu ops for VM statistics
...
Fix up trivial (famous last words) global per-cpu naming conflicts in
arch/x86/kvm/svm.c
mm/slab.c
Avoid generating files in the now deprecated asm-ia64 dir
Simplified the logic in the Makefile when editing stuff in the area
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
The simplest method was to add an extra asm-offsets.h
file in arch/$ARCH/include/asm that references the generated file.
We can now migrate the architectures one-by-one to reference
the generated file direct - and when done we can delete the
temporary arch/$ARCH/include/asm/asm-offsets.h file.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Michal Marek <mmarek@suse.cz>
Build warning:
<stdin>:1523:2: warning: #warning syscall recvmmsg not implemented
Because when recvmmesg was added, the previous syscall define was
cut&pasted, and a spurious "rt_" left in the name of the define.
Signed-off-by: Tony Luck <tony.luck@intel.com>
* 'for-2.6.33' of git://git.kernel.dk/linux-2.6-block: (113 commits)
cfq-iosched: Do not access cfqq after freeing it
block: include linux/err.h to use ERR_PTR
cfq-iosched: use call_rcu() instead of doing grace period stall on queue exit
blkio: Allow CFQ group IO scheduling even when CFQ is a module
blkio: Implement dynamic io controlling policy registration
blkio: Export some symbols from blkio as its user CFQ can be a module
block: Fix io_context leak after failure of clone with CLONE_IO
block: Fix io_context leak after clone with CLONE_IO
cfq-iosched: make nonrot check logic consistent
io controller: quick fix for blk-cgroup and modular CFQ
cfq-iosched: move IO controller declerations to a header file
cfq-iosched: fix compile problem with !CONFIG_CGROUP
blkio: Documentation
blkio: Wait on sync-noidle queue even if rq_noidle = 1
blkio: Implement group_isolation tunable
blkio: Determine async workload length based on total number of queues
blkio: Wait for cfq queue to get backlogged if group is empty
blkio: Propagate cgroup weight updation to cfq groups
blkio: Drop the reference to queue once the task changes cgroup
blkio: Provide some isolation between groups
...
* 'kvm-updates/2.6.33' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (84 commits)
KVM: VMX: Fix comparison of guest efer with stale host value
KVM: s390: Fix prefix register checking in arch/s390/kvm/sigp.c
KVM: Drop user return notifier when disabling virtualization on a cpu
KVM: VMX: Disable unrestricted guest when EPT disabled
KVM: x86 emulator: limit instructions to 15 bytes
KVM: s390: Make psw available on all exits, not just a subset
KVM: x86: Add KVM_GET/SET_VCPU_EVENTS
KVM: VMX: Report unexpected simultaneous exceptions as internal errors
KVM: Allow internal errors reported to userspace to carry extra data
KVM: Reorder IOCTLs in main kvm.h
KVM: x86: Polish exception injection via KVM_SET_GUEST_DEBUG
KVM: only clear irq_source_id if irqchip is present
KVM: x86: disallow KVM_{SET,GET}_LAPIC without allocated in-kernel lapic
KVM: x86: disallow multiple KVM_CREATE_IRQCHIP
KVM: VMX: Remove vmx->msr_offset_efer
KVM: MMU: update invlpg handler comment
KVM: VMX: move CR3/PDPTR update to vmx_set_cr3
KVM: remove duplicated task_switch check
KVM: powerpc: Fix BUILD_BUG_ON condition
KVM: VMX: Use shared msr infrastructure
...
Trivial conflicts due to new Kconfig options in arch/Kconfig and kernel/Makefile
Maintain back mapping from irqchip/pin to gsi to speedup
interrupt acknowledgment notifications.
[avi: build fix on non-x86/ia64]
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Mtdblock driver doesn't call flush_dcache_page for pages in request. So,
this causes problems on architectures where the icache doesn't fill from
the dcache or with dcache aliases. The patch fixes this.
The ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE symbol was introduced to avoid
pointless empty cache-thrashing loops on architectures for which
flush_dcache_page() is a no-op. Every architecture was provided with this
flush pages on architectires where ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE is
equal 1 or do nothing otherwise.
See "fix mtd_blkdevs problem with caches on some architectures" discussion
on LKML for more information.
Signed-off-by: Ilya Loginov <isloginov@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Peter Horton <phorton@bitbox.co.uk>
Cc: "Ed L. Cashin" <ecashin@coraid.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This patch fixes the following compilation error introduced by a PCI related
features.
The change set of 5dd1af9f84c79bedd589db89e71ca733f3bf0ebd moves some
xen related definitions from the arch header file
(x86/include/asm/xen/hypervisor.h) to the common header file
(include/xen/xen.h). So ia64/xen also follows it.
In file included from linux-next/include/xen/grant_table.h:41,
from linux-next/drivers/block/xen-blkfront.c:48:
linux-next/arch/ia64/include/asm/xen/hypervisor.h:43: error: nested redefinition of 'enum xen_domain_type'
linux-next/arch/ia64/include/asm/xen/hypervisor.h:43: error: redeclaration of 'enum xen_domain_type'
linux-next/arch/ia64/include/asm/xen/hypervisor.h:44: error: redeclaration of enumerator 'XEN_NATIVE'
linux-next/include/xen/xen.h:5: error: previous definition of 'XEN_NATIVE' was here
linux-next/arch/ia64/include/asm/xen/hypervisor.h:45: error: redeclaration of enumerator 'XEN_PV_DOMAIN'
linux-next/include/xen/xen.h:6: error: previous definition of 'XEN_PV_DOMAIN' was here
linux-next/arch/ia64/include/asm/xen/hypervisor.h:46: error: redeclaration of enumerator 'XEN_HVM_DOMAIN'
linux-next/include/xen/xen.h:7: error: previous definition of 'XEN_HVM_DOMAIN' was here
Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
This reverts commit b94b08081f.
genksyms currently cannot handle complicated types for exported
percpu variables. Drop this patch for now as it prevents a
module from being loaded on sn2 systems:
xpc: no symbol version for per_cpu____sn_cnodeid_to_nasid
xpc: Unknown symbol per_cpu____sn_cnodeid_to_nasid
Signed-off-by: Tony Luck <tony.luck@intel.com>
This patch updates percpu related symbols in ia64 such that percpu
symbols are unique and don't clash with local symbols. This serves
two purposes of decreasing the possibility of global percpu symbol
collision and allowing dropping per_cpu__ prefix from percpu symbols.
* arch/ia64/kernel/setup.c: s/cpu_info/ia64_cpu_info/
Partly based on Rusty Russell's "alloc_percpu: rename percpu vars
which cause name clashes" patch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: linux-ia64@vger.kernel.org
Reported-by: "Tony Luck" <tony.luck@intel.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Create a new socket level option to report number of queue overflows
Recently I augmented the AF_PACKET protocol to report the number of frames lost
on the socket receive queue between any two enqueued frames. This value was
exported via a SOL_PACKET level cmsg. AFter I completed that work it was
requested that this feature be generalized so that any datagram oriented socket
could make use of this option. As such I've created this patch, It creates a
new SOL_SOCKET level option called SO_RXQ_OVFL, which when enabled exports a
SOL_SOCKET level cmsg that reports the nubmer of times the sk_receive_queue
overflowed between any two given frames. It also augments the AF_PACKET
protocol to take advantage of this new feature (as it previously did not touch
sk->sk_drops, which this patch uses to record the overflow count). Tested
successfully by me.
Notes:
1) Unlike my previous patch, this patch simply records the sk_drops value, which
is not a number of drops between packets, but rather a total number of drops.
Deltas must be computed in user space.
2) While this patch currently works with datagram oriented protocols, it will
also be accepted by non-datagram oriented protocols. I'm not sure if thats
agreeable to everyone, but my argument in favor of doing so is that, for those
protocols which aren't applicable to this option, sk_drops will always be zero,
and reporting no drops on a receive queue that isn't used for those
non-participating protocols seems reasonable to me. This also saves us having
to code in a per-protocol opt in mechanism.
3) This applies cleanly to net-next assuming that commit
977750076d (my af packet cmsg patch) is reverted
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Linus pointed out that other people have spent large amounts of time
and effort to optimize the layout of frequently used structures. Often
these have embedded locks, and the assumption is that a lock takes
4 bytes. Linus also pointed out how to work with the limited options
for atomic instructions on Itanium.
Signed-off-by: Tony Luck <tony.luck@intel.com>
