13 Jun, 2014
1 commit
-
Pull networking updates from David Miller:
1) Seccomp BPF filters can now be JIT'd, from Alexei Starovoitov.
2) Multiqueue support in xen-netback and xen-netfront, from Andrew J
Benniston.3) Allow tweaking of aggregation settings in cdc_ncm driver, from Bjørn
Mork.4) BPF now has a "random" opcode, from Chema Gonzalez.
5) Add more BPF documentation and improve test framework, from Daniel
Borkmann.6) Support TCP fastopen over ipv6, from Daniel Lee.
7) Add software TSO helper functions and use them to support software
TSO in mvneta and mv643xx_eth drivers. From Ezequiel Garcia.8) Support software TSO in fec driver too, from Nimrod Andy.
9) Add Broadcom SYSTEMPORT driver, from Florian Fainelli.
10) Handle broadcasts more gracefully over macvlan when there are large
numbers of interfaces configured, from Herbert Xu.11) Allow more control over fwmark used for non-socket based responses,
from Lorenzo Colitti.12) Do TCP congestion window limiting based upon measurements, from Neal
Cardwell.13) Support busy polling in SCTP, from Neal Horman.
14) Allow RSS key to be configured via ethtool, from Venkata Duvvuru.
15) Bridge promisc mode handling improvements from Vlad Yasevich.
16) Don't use inetpeer entries to implement ID generation any more, it
performs poorly, from Eric Dumazet.* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1522 commits)
rtnetlink: fix userspace API breakage for iproute2 < v3.9.0
tcp: fixing TLP's FIN recovery
net: fec: Add software TSO support
net: fec: Add Scatter/gather support
net: fec: Increase buffer descriptor entry number
net: fec: Factorize feature setting
net: fec: Enable IP header hardware checksum
net: fec: Factorize the .xmit transmit function
bridge: fix compile error when compiling without IPv6 support
bridge: fix smatch warning / potential null pointer dereference
via-rhine: fix full-duplex with autoneg disable
bnx2x: Enlarge the dorq threshold for VFs
bnx2x: Check for UNDI in uncommon branch
bnx2x: Fix 1G-baseT link
bnx2x: Fix link for KR with swapped polarity lane
sctp: Fix sk_ack_backlog wrap-around problem
net/core: Add VF link state control policy
net/fsl: xgmac_mdio is dependent on OF_MDIO
net/fsl: Make xgmac_mdio read error message useful
net_sched: drr: warn when qdisc is not work conserving
...
12 Jun, 2014
1 commit
-
This function sets the n'th cpu - local cpu's first.
For example: in a 16 cores server with even cpu's local, will get the
following values:
cpumask_set_cpu_local_first(0, numa, cpumask) => cpu 0 is set
cpumask_set_cpu_local_first(1, numa, cpumask) => cpu 2 is set
...
cpumask_set_cpu_local_first(7, numa, cpumask) => cpu 14 is set
cpumask_set_cpu_local_first(8, numa, cpumask) => cpu 1 is set
cpumask_set_cpu_local_first(9, numa, cpumask) => cpu 3 is set
...
cpumask_set_cpu_local_first(15, numa, cpumask) => cpu 15 is setCurently this function will be used by multi queue networking devices to
calculate the irq affinity mask, such that as many local cpu's as
possible will be utilized to handle the mq device irq's.Signed-off-by: Amir Vadai
Signed-off-by: David S. Miller
02 Jun, 2014
2 commits
-
This reverts commit 70a640d0dae3a9b1b222ce673eb5d92c263ddd61
("net/mlx4_en: Use affinity hint") and commit
c8865b64b05b2f4eeefd369373e9c8aeb069e7a1 ("cpumask: Utility function
to set n'th cpu - local cpu first") because these changes break
the build when SMP is disabled amongst other things.Reported-by: Eric Dumazet
Signed-off-by: David S. Miller -
This function sets the n'th cpu - local cpu's first.
For example: in a 16 cores server with even cpu's local, will get the
following values:
cpumask_set_cpu_local_first(0, numa, cpumask) => cpu 0 is set
cpumask_set_cpu_local_first(1, numa, cpumask) => cpu 2 is set
...
cpumask_set_cpu_local_first(7, numa, cpumask) => cpu 14 is set
cpumask_set_cpu_local_first(8, numa, cpumask) => cpu 1 is set
cpumask_set_cpu_local_first(9, numa, cpumask) => cpu 3 is set
...
cpumask_set_cpu_local_first(15, numa, cpumask) => cpu 15 is setCurently this function will be used by multi queue networking devices to
calculate the irq affinity mask, such that as many local cpu's as
possible will be utilized to handle the mq device irq's.Signed-off-by: Amir Vadai
Signed-off-by: David S. Miller
14 May, 2014
1 commit
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Silence the warning when building with -Wsign-compare when cpumask.h
is included:include/linux/cpumask.h: In function ‘cpumask_parse’:
include/linux/cpumask.h:603:26: warning: signed and unsigned type in conditional expression [-Wsign-compare]
int len = nl ? nl - buf : strlen(buf);
^V2: Rusty pointed out that unsigned should be used instead.
Signed-off-by: Brian W Hart
Signed-off-by: Rusty Russell
13 Mar, 2013
1 commit
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We have cpulist_parse() but not cpumask_parse(). Implement it using
bitmap_parse().bitmap_parse() is weird in that it takes @len for a string in
kernel-memory which also is inconsistent with bitmap_parselist().
Make cpumask_parse() calculate the length and don't expose the
inconsistency to cpumask users. Maybe we can fix up bitmap_parse()
later.This will be used to expose workqueue cpumask knobs to userland via
sysfs.Signed-off-by: Tejun Heo
Cc: Rusty Russell
27 Jul, 2012
2 commits
-
As introduced in Rusty's commit 29c0177e6a4, the function has no
parameter @len, so need to remove it from comments to avoid kernel-doc
warning:alexs@debian:~/linux-next$ scripts/kernel-doc -man
include/linux/cpumask.h | split-man.pl /tmp/man
....
Warning(include/linux/cpumask.h:602): Excess function parameter 'len'
description in 'cpulist_parse'and correct the function name in comments to cpulist_parse.
Signed-off-by: Alex Shi
Signed-off-by: Rusty Russell -
Current few cpumask functions' purposes are not quite clear. Stupid
user like myself needs to dig into details for clear function
purpose and return value.
Add few explanation for them is helpful.Thanks for Srivatsa's comments and correction!
Signed-off-by: Alex Shi
Acked-by: KOSAKI Motohiro
Signed-off-by: Rusty Russell
29 Mar, 2012
2 commits
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These are obsolete: cpu_*_mask provides (const) pointers.
Signed-off-by: Rusty Russell
-
__any_online_cpu() is not optimal and also unnecessary. So, replace its
use by faster cpumask_* operations.Signed-off-by: Srivatsa S. Bhat
Cc: Eric Dumazet
Cc: Venkatesh Pallipadi
Cc: Rusty Russell
Cc: KOSAKI Motohiro
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
05 Mar, 2012
1 commit
-
If a header file is making use of BUG, BUG_ON, BUILD_BUG_ON, or any
other BUG variant in a static inline (i.e. not in a #define) then
that header really should be including and not just
expecting it to be implicitly present.We can make this change risk-free, since if the files using these
headers didn't have exposure to linux/bug.h already, they would have
been causing compile failures/warnings.Signed-off-by: Paul Gortmaker
27 Jul, 2011
1 commit
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cpumask_var_t has one notable difference from cpumask_t. Add the
explanation.Signed-off-by: KOSAKI Motohiro
Cc: Thiago Farina
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
25 May, 2011
1 commit
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Manually adjusting the smp_affinity for IRQ's becomes unwieldy when the
cpu count is large.Setting smp affinity to cpus 256 to 263 would be:
echo 000000ff,00000000,00000000,00000000,00000000,00000000,00000000,00000000 > smp_affinity
instead of:
echo 256-263 > smp_affinity_list
Think about what it looks like for cpus around say, 4088 to 4095.
We already have many alternate "list" interfaces:
/sys/devices/system/cpu/cpuX/indexY/shared_cpu_list
/sys/devices/system/cpu/cpuX/topology/thread_siblings_list
/sys/devices/system/cpu/cpuX/topology/core_siblings_list
/sys/devices/system/node/nodeX/cpulist
/sys/devices/pci***/***/local_cpulistAdd a companion interface, smp_affinity_list to use cpu lists instead of
cpu maps. This conforms to other companion interfaces where both a map
and a list interface exists.This required adding a bitmap_parselist_user() function in a manner
similar to the bitmap_parse_user() function.[akpm@linux-foundation.org: make __bitmap_parselist() static]
Signed-off-by: Mike Travis
Cc: Thomas Gleixner
Cc: Jack Steiner
Cc: Lee Schermerhorn
Cc: Andy Shevchenko
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
07 Mar, 2010
1 commit
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Dependent on CONFIG_SMP the num_*_cpus() functions return unsigned or
signed values. Let them always return unsigned values to avoid strange
casts.Fixes at least one warning:
kernel/kprobes.c: In function 'register_kretprobe':
kernel/kprobes.c:1038: warning: comparison of distinct pointer types lacks a castSigned-off-by: Heiko Carstens
Cc: Heiko Carstens
Cc: Ananth N Mavinakayanahalli
Cc: Masami Hiramatsu
Cc: Ingo Molnar
Cc: Rusty Russell
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
25 Feb, 2010
1 commit
-
Currently, rcu_needs_cpu() simply checks whether the current CPU
has an outstanding RCU callback, which means that the last CPU
to go into dyntick-idle mode might wait a few ticks for the
relevant grace periods to complete. However, if all the other
CPUs are in dyntick-idle mode, and if this CPU is in a quiescent
state (which it is for RCU-bh and RCU-sched any time that we are
considering going into dyntick-idle mode), then the grace period
is instantly complete.This patch therefore repeatedly invokes the RCU grace-period
machinery in order to force any needed grace periods to complete
quickly. It does so a limited number of times in order to
prevent starvation by an RCU callback function that might pass
itself to call_rcu().However, if any CPU other than the current one is not in
dyntick-idle mode, fall back to simply checking (with fix to bug
noted by Lai Jiangshan). Also, take advantage of last
grace-period forcing, the opportunity to do so noted by Steve
Rostedt. And apply simplified #ifdef condition suggested by
Frederic Weisbecker.Signed-off-by: Paul E. McKenney
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
LKML-Reference:
Signed-off-by: Ingo Molnar
07 Dec, 2009
1 commit
-
Since (e761b77: cpu hotplug, sched: Introduce cpu_active_map and redo
sched domain managment) we have cpu_active_mask which is suppose to rule
scheduler migration and load-balancing, except it never (fully) did.The particular problem being solved here is a crash in try_to_wake_up()
where select_task_rq() ends up selecting an offline cpu because
select_task_rq_fair() trusts the sched_domain tree to reflect the
current state of affairs, similarly select_task_rq_rt() trusts the
root_domain.However, the sched_domains are updated from CPU_DEAD, which is after the
cpu is taken offline and after stop_machine is done. Therefore it can
race perfectly well with code assuming the domains are right.Cure this by building the domains from cpu_active_mask on
CPU_DOWN_PREPARE.Signed-off-by: Peter Zijlstra
LKML-Reference:
Signed-off-by: Ingo Molnar
24 Sep, 2009
4 commits
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The new ones have pretty kerneldoc. Move the old ones to the end to
avoid confusing people.Signed-off-by: Rusty Russell
Cc: benh@kernel.crashing.org -
We're not forcing removal of the old cpu_ functions, but we might as
well delete the now-unused ones.Especially CPUMASK_ALLOC and friends. I actually got a phone call (!)
from a hacker who thought I had introduced them as the new cpumask
API. He seemed bewildered that I had lost all taste.Signed-off-by: Rusty Russell
Cc: benh@kernel.crashing.org -
It's only defined for NR_CPUS > BITS_PER_LONG; cpu_all_mask is always
defined (and const).Signed-off-by: Rusty Russell
-
(Thanks to Al Viro for reminding me of this, via Ingo)
CPU_MASK_ALL is the (deprecated) "all bits set" cpumask, defined as so:
#define CPU_MASK_ALL (cpumask_t) { { ... } }
Taking the address of such a temporary is questionable at best,
unfortunately 321a8e9d (cpumask: add CPU_MASK_ALL_PTR macro) added
CPU_MASK_ALL_PTR:#define CPU_MASK_ALL_PTR (&CPU_MASK_ALL)
Which formalizes this practice. One day gcc could bite us over this
usage (though we seem to have gotten away with it so far).Now all callers are removed, we kill it.
Signed-off-by: Rusty Russell
Acked-by: Ingo Molnar
Reported-by: Al Viro
Cc: Mike Travis
23 Sep, 2009
1 commit
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This patch can remove spinlock from struct call_function_data, the
reasons are below:1: add a new interface for cpumask named cpumask_test_and_clear_cpu(),
it can atomically test and clear specific cpu, we can use it instead
of cpumask_test_cpu() and cpumask_clear_cpu() and no need data->lock
to protect those in generic_smp_call_function_interrupt().2: in smp_call_function_many(), after csd_lock() return, the current's
cfd_data is deleted from call_function list, so it not have race
between other cpus, then cfs_data is only used in
smp_call_function_many() that must disable preemption and not from
a hardware interrupthandler or from a bottom half handler to call,
only the correspond cpu can use it, so it not have race in current
cpu, no need cfs_data->lock to protect it.3: after 1 and 2, cfs_data->lock is only use to protect cfs_data->refs in
generic_smp_call_function_interrupt(), so we can define cfs_data->refs
to atomic_t, and no need cfs_data->lock any more.Signed-off-by: Xiao Guangrong
Cc: Ingo Molnar
Cc: Jens Axboe
Cc: Nick Piggin
Cc: Peter Zijlstra
Acked-by: Rusty Russell
[akpm@linux-foundation.org: use atomic_dec_return()]
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
22 Aug, 2009
1 commit
-
When 'and'ing two bitmasks (where 'andnot' is a variation on it), some
cases want to know whether the result is the empty set or not. In
particular, the TLB IPI sending code wants to do cpumask operations and
determine if there are any CPU's left in the final set.So this just makes the bitmask (and cpumask) functions return a boolean
for whether the result has any bits set.Cc: stable@kernel.org (2.6.30, needed by TLB shootdown fix)
Signed-off-by: Linus Torvalds
09 Jun, 2009
1 commit
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So can get cpumask_var with cpumask_clear
Signed-off-by: Yinghai Lu
Signed-off-by: Rusty Russell
01 Jan, 2009
1 commit
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Impact: new debug CONFIG options
This helps find unconverted code. It currently breaks compile horribly,
but we never wanted a flag day so that's expected.Signed-off-by: Rusty Russell
30 Dec, 2008
3 commits
-
They're only for use in boot/cpu hotplug code anyway, and this avoids
the use of deprecated cpu_*_map.Stephen Rothwell points out that gcc 4.2.4 (on powerpc at least)
didn't like the cast away of const anyway:include/linux/cpumask.h: In function 'set_cpu_possible':
include/linux/cpumask.h:1052: warning: passing argument 2 of 'cpumask_set_cpu' discards qualifiers from pointer target typeSo this kills two birds with one stone.
Signed-off-by: Rusty Russell
-
Changes:
1) cpumask_t to struct cpumask,
2) cpus_weight_nr to cpumask_weight,
3) cpu_isset to cpumask_test_cpu,
4) ->bits to cpumask_bits()
5) cpu_*_map to cpu_*_mask.
6) for_each_cpu_mask_nr to for_each_cpuSigned-off-by: Rusty Russell
-
Impact: cleanup
This implements the obsolescent cpu_online_map in terms of
cpu_online_mask, rather than the other way around. Same for the other
maps.The documentation comments are also updated to refer to _mask rather
than _map.Signed-off-by: Rusty Russell
Signed-off-by: Mike Travis
19 Dec, 2008
1 commit
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Impact: New API
This will be needed in x86 code to allocate the domain and old_domain
cpumasks on the same node as where the containing irq_cfg struct is
allocated.(Also fixes double-dump_stack on rare CONFIG_DEBUG_PER_CPU_MAPS case)
Signed-off-by: Mike Travis
Signed-off-by: Rusty Russell (re-impl alloc_cpumask_var)
13 Dec, 2008
2 commits
-
Impact: futureproof as we convert more code to new APIs
The old cpumask operators treat all NR_CPUS bits as relevent, the new
ones use nr_cpumask_bits. For large NR_CPUS and small nr_cpu_ids, this
makes a difference.However, mixing the two can cause problems with undefined bits. An
arch which sets CONFIG_CPUMASK_OFFSTACK should have converted across
to the new operators, so it's safe in that case.(Thanks to Stephen Rothwell for bisecting the initial unused-bits bug,
and Mike Travis for this solution).Signed-off-by: Rusty Russell
Cc: Mike Travis -
…t_scnprintf to take pointers.
Impact: change calling convention of existing cpumask APIs
Most cpumask functions started with cpus_: these have been replaced by
cpumask_ ones which take struct cpumask pointers as expected.These four functions don't have good replacement names; fortunately
they're rarely used, so we just change them over.Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Mike Travis <travis@sgi.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: paulus@samba.org
Cc: mingo@redhat.com
Cc: tony.luck@intel.com
Cc: ralf@linux-mips.org
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: cl@linux-foundation.org
Cc: srostedt@redhat.com
10 Nov, 2008
1 commit
-
Impact: cleanup
Clean up based on feedback from Andrew Morton and others:
- change to inline functions instead of macros
- add __init to bootmem method
- add a missing debug checkSigned-off-by: Rusty Russell
Signed-off-by: Ingo Molnar
07 Nov, 2008
1 commit
-
- add cpumask_of()
- add free_bootmem_cpumask_var()Signed-off-by: Rusty Russell
Signed-off-by: Ingo Molnar
06 Nov, 2008
1 commit
-
Impact: introduce new APIs
We want to deprecate cpumasks on the stack, as we are headed for
gynormous numbers of CPUs. Eventually, we want to head towards an
undefined 'struct cpumask' so they can never be declared on stack.1) New cpumask functions which take pointers instead of copies.
(cpus_* -> cpumask_*)2) Several new helpers to reduce requirements for temporary cpumasks
(cpumask_first_and, cpumask_next_and, cpumask_any_and)3) Helpers for declaring cpumasks on or offstack for large NR_CPUS
(cpumask_var_t, alloc_cpumask_var and free_cpumask_var)4) 'struct cpumask' for explicitness and to mark new-style code.
5) Make iterator functions stop at nr_cpu_ids (a runtime constant),
not NR_CPUS for time efficiency and for smaller dynamic allocations
in future.6) cpumask_copy() so we can allocate less than a full cpumask eventually
(for alloc_cpumask_var), and so we can eliminate the 'struct cpumask'
definition eventually.7) work_on_cpu() helper for doing task on a CPU, rather than saving old
cpumask for current thread and manipulating it.8) smp_call_function_many() which is smp_call_function_mask() except
taking a cpumask pointer.Note that this patch simply introduces the new functions and leaves
the obsolescent ones in place. This is to simplify the transition
patches.Signed-off-by: Rusty Russell
Signed-off-by: Ingo Molnar
31 Jul, 2008
1 commit
-
when you take the address of the result. Noticed on a sparc64 compile
using a version 3.4.5 cross compiler.kernel/time/tick-common.c: In function `tick_check_new_device':
kernel/time/tick-common.c:210: error: invalid lvalue in unary `&'
...Just make it a regular expression.
Signed-off-by: Stephen Rothwell
Acked-by: Ingo Molnar
Signed-off-by: Linus Torvalds
29 Jul, 2008
1 commit
-
Clean up and optimize cpumask_of_cpu(), by sharing all the zero words.
Instead of stupidly generating all possible i=0...NR_CPUS 2^i patterns
creating a huge array of constant bitmasks, realize that the zero words
can be shared.In other words, on a 64-bit architecture, we only ever need 64 of these
arrays - with a different bit set in one single world (with enough zero
words around it so that we can create any bitmask by just offsetting in
that big array). And then we just put enough zeroes around it that we
can point every single cpumask to be one of those things.So when we have 4k CPU's, instead of having 4k arrays (of 4k bits each,
with one bit set in each array - 2MB memory total), we have exactly 64
arrays instead, each 8k bits in size (64kB total).And then we just point cpumask(n) to the right position (which we can
calculate dynamically). Once we have the right arrays, getting
"cpumask(n)" ends up being:static inline const cpumask_t *get_cpu_mask(unsigned int cpu)
{
const unsigned long *p = cpu_bit_bitmap[1 + cpu % BITS_PER_LONG];
p -= cpu / BITS_PER_LONG;
return (const cpumask_t *)p;
}This brings other advantages and simplifications as well:
- we are not wasting memory that is just filled with a single bit in
various different places- we don't need all those games to re-create the arrays in some dense
format, because they're already going to be dense enough.if we compile a kernel for up to 4k CPU's, "wasting" that 64kB of memory
is a non-issue (especially since by doing this "overlapping" trick we
probably get better cache behaviour anyway).[ mingo@elte.hu:
Converted Linus's mails into a commit. See:
http://lkml.org/lkml/2008/7/27/156
http://lkml.org/lkml/2008/7/28/320Also applied a family filter - which also has the side-effect of leaving
out the bits where Linus calls me an idio... Oh, never mind ;-)
]Signed-off-by: Ingo Molnar
Cc: Rusty Russell
Cc: Andrew Morton
Cc: Al Viro
Cc: Mike Travis
Signed-off-by: Ingo Molnar
26 Jul, 2008
1 commit
-
If an arch doesn't define cpumask_of_cpu_map, create a generic
statically-initialized one for them. This allows removal of the buggy
cpumask_of_cpu() macro (&cpumask_of_cpu() gives address of
out-of-scope var).An arch with NR_CPUS of 4096 probably wants to allocate this itself
based on the actual number of CPUs, since otherwise they're using 2MB
of rodata (1024 cpus means 128k). That's what
CONFIG_HAVE_CPUMASK_OF_CPU_MAP is for (only x86/64 does so at the
moment).In future as we support more CPUs, we'll need to resort to a
get_cpu_map()/put_cpu_map() allocation scheme.Signed-off-by: Mike Travis
Signed-off-by: Rusty Russell
Cc: Andrew Morton
Cc: Jack Steiner
Signed-off-by: Ingo Molnar
24 Jul, 2008
1 commit
-
* 'sched/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
sched: hrtick_enabled() should use cpu_active()
sched, x86: clean up hrtick implementation
sched: fix build error, provide partition_sched_domains() unconditionally
sched: fix warning in inc_rt_tasks() to not declare variable 'rq' if it's not needed
cpu hotplug: Make cpu_active_map synchronization dependency clear
cpu hotplug, sched: Introduce cpu_active_map and redo sched domain managment (take 2)
sched: rework of "prioritize non-migratable tasks over migratable ones"
sched: reduce stack size in isolated_cpu_setup()
Revert parts of "ftrace: do not trace scheduler functions"Fixed up conflicts in include/asm-x86/thread_info.h (due to the
TIF_SINGLESTEP unification vs TIF_HRTICK_RESCHED removal) and
kernel/sched_fair.c (due to cpu_active_map vs for_each_cpu_mask_nr()
introduction).
20 Jul, 2008
1 commit
-
* Rename CPUMASK_VAR --> CPUMASK_PTR (and simplify)
* Fix a semantic error in CPUMASK_ALLOC
* Add a bit of commentry to cpumask.h
Signed-off-by: Mike Travis
Signed-off-by: Ingo Molnar
19 Jul, 2008
2 commits
-
* Provide a generic set of CPUMASK_ALLOC macros patterned after the
SCHED_CPUMASK_ALLOC macros. This is used where multiple cpumask_t
variables are declared on the stack to reduce the amount of stack
space required.Signed-off-by: Mike Travis
Signed-off-by: Ingo Molnar -
* This patch replaces the dangerous lvalue version of cpumask_of_cpu
with new cpumask_of_cpu_ptr macros. These are patterned after the
node_to_cpumask_ptr macros.In general terms, if there is a cpumask_of_cpu_map[] then a pointer to
the cpumask_of_cpu_map[cpu] entry is used. The cpumask_of_cpu_map
is provided when there is a large NR_CPUS count, reducing
greatly the amount of code generated and stack space used for
cpumask_of_cpu(). The pointer to the cpumask_t value is needed for
calling set_cpus_allowed_ptr() to reduce the amount of stack space
needed to pass the cpumask_t value.If there isn't a cpumask_of_cpu_map[], then a temporary variable is
declared and filled in with value from cpumask_of_cpu(cpu) as well as
a pointer variable pointing to this temporary variable. Afterwards,
the pointer is used to reference the cpumask value. The compiler
will optimize out the extra dereference through the pointer as well
as the stack space used for the pointer, resulting in identical code.A good example of the orthogonal usages is in net/sunrpc/svc.c:
case SVC_POOL_PERCPU:
{
unsigned int cpu = m->pool_to[pidx];
cpumask_of_cpu_ptr(cpumask, cpu);*oldmask = current->cpus_allowed;
set_cpus_allowed_ptr(current, cpumask);
return 1;
}
case SVC_POOL_PERNODE:
{
unsigned int node = m->pool_to[pidx];
node_to_cpumask_ptr(nodecpumask, node);*oldmask = current->cpus_allowed;
set_cpus_allowed_ptr(current, nodecpumask);
return 1;
}Signed-off-by: Mike Travis
Signed-off-by: Ingo Molnar