With the introduction of the .brk section, special care must be taken
that no unused page table entries remain if _brk_end and _end are
separated by a 2M page boundary. cleanup_highmap() runs very early and
hence cannot take care of that, hence potential entries needing to be
removed past _brk_end must be cleared once the brk allocator has done
its job.
[ Impact: avoids undesirable TLB aliases ]
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Merge reason: tracing/core was on a .30-rc1 base and was missing out on
on a handful of tracing fixes present in .30-rc5-almost.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The mem= option will truncate the memory map at a specified address so
it's not possible to register nodes with memory beyond the e820 upper
bound.
unparse_node() is only called when then node had memory associated with
it, although with the mem= option it is no longer addressable.
[ Impact: fix boot hang on certain (large) systems ]
Reported-by: "Zhang, Yanmin" <yanmin_zhang@linux.intel.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Jack Steiner <steiner@sgi.com>
LKML-Reference: <alpine.DEB.2.00.0905051248150.20021@chino.kir.corp.google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
tracing: x86, mmiotrace: fix range test
tracing: fix ref count in splice pages
Follow up to afcfe024ae in Linus' tree
("x86: mmiotrace: quieten spurious warning message")
Signed-off-by: Stuart Bennett <stuart@freedesktop.org>
Acked-by: Pekka Paalanen <pq@iki.fi>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <1240946271-7083-5-git-send-email-stuart@freedesktop.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* change function names to clear_* from set_*: in reality we only clear
and restore page presence, and never unconditionally set present.
Using clear_*({true, false}, ...) is therefore more honest than
set_*({false, true}, ...)
* upgrade presence storage to pteval_t: doing user-space tracing will
require saving and manipulation of the _PAGE_PROTNONE bit, in addition
to the existing _PAGE_PRESENT changes, and having multiple bools stored
and passed around does not seem optimal
[ Impact: refactor, clean up mmiotrace code ]
Signed-off-by: Stuart Bennett <stuart@freedesktop.org>
Acked-by: Pekka Paalanen <pq@iki.fi>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <1240946271-7083-4-git-send-email-stuart@freedesktop.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
kmmio_probe being *p and kmmio_fault_page being sometimes *f and
sometimes *p is not helpful.
[ Impact: cleanup ]
Signed-off-by: Stuart Bennett <stuart@freedesktop.org>
Acked-by: Pekka Paalanen <pq@iki.fi>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <1240946271-7083-3-git-send-email-stuart@freedesktop.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Commit dc09855 ("x86/uv: fix init of memory-less nodes") causes a
two sockets system (where node-1 doesn't have RAM installed) to crash.
That commit makes node_possible include cpu nodes that do not have memory.
So check boundary in setup_node_bootmem().
[ Impact: fix boot crash on RAM-less NUMA node system ]
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Jack Steiner <steiner@sgi.com>
LKML-Reference: <49EF89DF.9090404@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
calculate_numa_remap_pages() is called only by __init initmem_init()
further calculate_numa_remap_pages is calling:
__init find_e820_area() and __init reserve_early()
So calculate_numa_remap_pages() should be __init calculate_numa_remap_pages().
WARNING: arch/x86/built-in.o(.text+0x82ea3): Section mismatch in reference from the function calculate_numa_remap_pages() to the function .init.text:find_e820_area()
The function calculate_numa_remap_pages() references
the function __init find_e820_area().
This is often because calculate_numa_remap_pages lacks a __init
annotation or the annotation of find_e820_area is wrong.
WARNING: arch/x86/built-in.o(.text+0x82f5f): Section mismatch in reference from the function calculate_numa_remap_pages() to the function .init.text:reserve_early()
The function calculate_numa_remap_pages() references
the function __init reserve_early().
This is often because calculate_numa_remap_pages lacks a __init
annotation or the annotation of reserve_early is wrong.
[ Impact: save memory, address Section mismatch warning ]
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
LKML-Reference: <1239991281.3153.4.camel@ht.satnam>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Add support for nodes that have cpus but no memory.
The current code was failing to add these nodes
to the nodes_present_map.
v2: Fixes case caught by David Rientjes - missed support
for the x2apic SRAT table.
[ Impact: fix potential boot crash on memory-less UV nodes. ]
Reported-by: David Rientjes <rientjes@google.com>
Signed-off-by: Jack Steiner <steiner@sgi.com>
LKML-Reference: <20090417142242.GA23743@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86: fix microcode driver newly spewing warnings
x86, PAT: Remove page granularity tracking for vm_insert_pfn maps
x86: disable X86_PTRACE_BTS for now
x86, documentation: kernel-parameters replace X86-32,X86-64 with X86
x86: pci-swiotlb.c swiotlb_dma_ops should be static
x86, PAT: Remove duplicate memtype reserve in devmem mmap
x86, PAT: Consolidate code in pat_x_mtrr_type() and reserve_memtype()
x86, PAT: Changing memtype to WC ensuring no WB alias
x86, PAT: Handle faults cleanly in set_memory_ APIs
x86, PAT: Change order of cpa and free in set_memory_wb
x86, CPA: Change idmap attribute before ioremap attribute setup
This change resolves the problem of too many single page entries
in pat_memtype_list and "freeing invalid memtype" errors with i915,
reported here:
http://marc.info/?l=linux-kernel&m=123845244713183&w=2
Remove page level granularity track and untrack of vm_insert_pfn.
memtype tracking at page granularity does not scale and cleaner
approach would be for the driver to request a type for a bigger
IO address range or PCI io memory range for that device, either at
mmap time or driver init time and just use that type during
vm_insert_pfn.
This patch just removes the track/untrack of vm_insert_pfn. That
means we will be in same state as 2.6.28, with respect to these APIs.
Newer APIs for the drivers to request a memtype for a bigger region
is coming soon.
[ Impact: fix Xorg startup warnings and hangs ]
Reported-by: Arkadiusz Miskiewicz <a.miskiewicz@gmail.com>
Tested-by: Arkadiusz Miskiewicz <a.miskiewicz@gmail.com>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
LKML-Reference: <20090408223716.GC3493@linux-os.sc.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
pat_disable cannot be __cpuinit anymore because it's called from pat_init
and the callchain looks like this:
pat_disable [cpuinit] <- pat_init <- generic_set_all <-
ipi_handler <- set_mtrr <- (other non init/cpuinit functions)
WARNING: arch/x86/mm/built-in.o(.text+0x449e): Section mismatch in reference
from the function pat_init() to the function .cpuinit.text:pat_disable()
The function pat_init() references
the function __cpuinit pat_disable().
This is often because pat_init lacks a __cpuinit
annotation or the annotation of pat_disable is wrong.
Non CONFIG_X86_PAT version of pat_disable is static inline, so this version
can be static too (and there are no callers outside of this file).
Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
LKML-Reference: <49DFB055.6070405@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: fix kprobes crash on 32-bit with RAM above 4G
Use phys_addr_t for receiving a physical address argument
instead of unsigned long. This allows fixmap to handle
pages higher than 4GB on x86-32.
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: systemtap-ml <systemtap@sources.redhat.com>
Cc: Gary Hade <garyhade@us.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <49DE3695.6040800@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
/dev/mem mmap code was doing memtype reserve/free for a while now.
Recently we added memtype tracking in remap_pfn_range, and /dev/mem mmap
uses it indirectly. So, we don't need seperate tracking in /dev/mem code
any more. That means another ~100 lines of code removed :-).
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
LKML-Reference: <20090409212709.085210000@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Fix pat_x_mtrr_type() to use UC_MINUS when the mtrr type return UC. This
is to be consistent with ioremap() and ioremap_nocache() which uses
UC_MINUS.
Consolidate the code such that reserve_memtype() also uses
pat_x_mtrr_type() when the caller doesn't specify any special attribute
(non WB attribute).
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
LKML-Reference: <20090409212708.939936000@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
As per SDM, there should not be any aliasing of a WC with any cacheable
type across CPUs. That is if one CPU is changing the identity map
memtype to _WC, no other CPU at the time of this change should not have a
TLB for this page that carries a WB attribute. SDM suggests to make the
page not present. But for that we will have to handle any page faults
that can potentially happen due to these pages being not present.
Other way to deal with this without having any WB mapping is to change
the page first to UC and then to WC. This ensures that we meet the SDM
requirement of no cacheable alais to WC page. This also has same or
lower overhead than marking the page not present and making it present
later.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <20090409212708.797481000@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Handle faults and do proper cleanups in set_memory_*() functions. In
some cases, these functions were not doing proper free on failure paths.
With the changes to tracking memtype of RAM pages in struct page instead
of pat list, we do not need the changes in commits c5e147. This patch
reverts that change.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <20090409212708.653222000@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
To be free of aliasing due to races, set_memory_* interfaces should
follow ordering of reserving, changing memtype to UC/WC, changing
memtype back to WB followed by free.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <20090409212708.512280000@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Change the identity mapping with the requested attribute first, before
we setup the virtual memory mapping with the new requested attribute.
This makes sure that there is no window when identity map'ed attribute
may disagree with ioremap range on the attribute type.
This also avoids doing cpa on the ioremap'ed address twice (first in
ioremap_page_range and then in ioremap_change_attr using vaddr), and
should improve ioremap performance a bit.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
LKML-Reference: <20090409212708.373330000@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
While better than get_user_pages(), the usage of gupf(),
especially the return values and the fact that it can
potentially only partially pin the range, warranted some
documentation.
Signed-off-by: Andy Grover <andy.grover@oracle.com>
Cc: npiggin@suse.de
Cc: akpm@linux-foundation.org
LKML-Reference: <1239320729-3262-1-git-send-email-andy.grover@oracle.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (413 commits)
tracing, net: fix net tree and tracing tree merge interaction
tracing, powerpc: fix powerpc tree and tracing tree interaction
ring-buffer: do not remove reader page from list on ring buffer free
function-graph: allow unregistering twice
trace: make argument 'mem' of trace_seq_putmem() const
tracing: add missing 'extern' keywords to trace_output.h
tracing: provide trace_seq_reserve()
blktrace: print out BLK_TN_MESSAGE properly
blktrace: extract duplidate code
blktrace: fix memory leak when freeing struct blk_io_trace
blktrace: fix blk_probes_ref chaos
blktrace: make classic output more classic
blktrace: fix off-by-one bug
blktrace: fix the original blktrace
blktrace: fix a race when creating blk_tree_root in debugfs
blktrace: fix timestamp in binary output
tracing, Text Edit Lock: cleanup
tracing: filter fix for TRACE_EVENT_FORMAT events
ftrace: Using FTRACE_WARN_ON() to check "freed record" in ftrace_release()
x86: kretprobe-booster interrupt emulation code fix
...
Fix up trivial conflicts in
arch/parisc/include/asm/ftrace.h
include/linux/memory.h
kernel/extable.c
kernel/module.c
* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-cpumask: (36 commits)
cpumask: remove cpumask allocation from idle_balance, fix
numa, cpumask: move numa_node_id default implementation to topology.h, fix
cpumask: remove cpumask allocation from idle_balance
x86: cpumask: x86 mmio-mod.c use cpumask_var_t for downed_cpus
x86: cpumask: update 32-bit APM not to mug current->cpus_allowed
x86: microcode: cleanup
x86: cpumask: use work_on_cpu in arch/x86/kernel/microcode_core.c
cpumask: fix CONFIG_CPUMASK_OFFSTACK=y cpu hotunplug crash
numa, cpumask: move numa_node_id default implementation to topology.h
cpumask: convert node_to_cpumask_map[] to cpumask_var_t
cpumask: remove x86 cpumask_t uses.
cpumask: use cpumask_var_t in uv_flush_tlb_others.
cpumask: remove cpumask_t assignment from vector_allocation_domain()
cpumask: make Xen use the new operators.
cpumask: clean up summit's send_IPI functions
cpumask: use new cpumask functions throughout x86
x86: unify cpu_callin_mask/cpu_callout_mask/cpu_initialized_mask/cpu_sibling_setup_mask
cpumask: convert struct cpuinfo_x86's llc_shared_map to cpumask_var_t
cpumask: convert node_to_cpumask_map[] to cpumask_var_t
x86: unify 32 and 64-bit node_to_cpumask_map
...
All logical processors with APIC ID values of 255 and greater will have their
APIC reported through Processor X2APIC structure (type-9 entry type) and all
logical processors with APIC ID less than 255 will have their APIC reported
through legacy Processor Local APIC (type-0 entry type) only. This is the
same case even for NMI structure reporting.
The Processor X2APIC Affinity structure provides the association between the
X2APIC ID of a logical processor and the proximity domain to which the logical
processor belongs.
For OSPM, Procssor IDs outside the 0-254 range are to be declared as Device()
objects in the ACPI namespace.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
i386 allnoconfig:
arch/x86/mm/iomap_32.c: In function 'is_io_mapping_possible':
arch/x86/mm/iomap_32.c:27: warning: comparison is always false due to limited range of data type
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Use debug_kmap_atomic in kmap_atomic, kmap_atomic_pfn, and
iomap_atomic_prot_pfn.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
x86 has debug_kmap_atomic_prot() which is error checking function for
kmap_atomic. It is usefull for the other architectures, although it needs
CONFIG_TRACE_IRQFLAGS_SUPPORT.
This patch exposes it to the other architectures.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Tetsuo Handa reported this link bug:
| arch/x86/mm/built-in.o(.init.text+0x1831): In function `early_ioremap_init':
| : undefined reference to `__this_fixmap_does_not_exist'
| make: *** [.tmp_vmlinux1] Error 1
Commit:8827247ffcc9e880cbe4705655065cf011265157 used a variable (which
would be optimized to constant) as fix_to_virt()'s parameter.
It's depended on gcc's optimization and fails on old gcc. (Tetsuo used gcc 3.3)
We can use __fix_to_vir() instead, because we know it's safe and
don't need link time error reporting.
Reported-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: Wang Chen <wangchen@cn.fujitsu.com>
Cc: sfr@canb.auug.org.au
LKML-Reference: <49C9FFEA.7060908@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This reverts commit 698609bdcd.
69860 breaks Xen booting, as it relies on head*.S to set up the fixmap
pagetables (as a side-effect of initializing the USB debug port).
Xen, however, does not boot via head*.S, and so the fixmap area is
not initialized.
The specific symptom of the crash is a fault in dmi_scan(), because
the pointer that early_ioremap returns is not actually present.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Jan Beulich <jbeulich@novell.com>
LKML-Reference: <49C43A8E.5090203@goop.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Add new interfaces:
set_pages_array_uc()
set_pages_array_wb()
that can be used change the page attribute for a bunch of pages with
flush etc done once at the end of all the changes. These interfaces
are similar to existing set_memory_array_uc() and set_memory_array_wc().
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: arjan@infradead.org
Cc: eric@anholt.net
Cc: airlied@redhat.com
LKML-Reference: <20090319215358.901545000@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Add struct page array pointer to cpa struct and CPA_PAGES_ARRAY.
With that we can add change_page_attr_set_clr() a parameter to pass
struct page array pointer and that can be handled by the underlying
cpa code.
cpa_flush_array() is also changed to support both addr array or
struct page pointer array, depending on the flag.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: arjan@infradead.org
Cc: eric@anholt.net
Cc: airlied@redhat.com
LKML-Reference: <20090319215358.758513000@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Change change_page_attr_set_clr() array parameter to a flag. This helps
following patches which adds an interface to change attr to uc/wb over a
set of pages referred by struct page.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: arjan@infradead.org
Cc: eric@anholt.net
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: airlied@redhat.com
LKML-Reference: <20090319215358.611346000@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup, remove last user of set_pte_present
set_pte_vaddr() is only used to install ptes in fixmaps, and
should never be used to overwrite a present mapping.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Xen-devel <xen-devel@lists.xensource.com>
LKML-Reference: <1237406613-2929-1-git-send-email-jeremy@goop.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup, reduce memory usage for CONFIG_CPUMASK_OFFSTACK=y
Part of the "getting rid of obsolete cpumask_t" patch:
1) Use cpumask_var_t: this is a pointer if CONFIG_CPUMASK_OFFSTACK=y
2) Call alloc_cpumask_var() on first entry into enter_uniprocessor()
3) Use modern cpumask_* functions.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Pekka Paalanen <pq@iki.fi>
LKML-Reference: <200903111633.55952.rusty@rustcorp.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: optimize APIC IPI related barriers
Uncached MMIO accesses for xapic are inherently serializing and hence
we don't need explicit barriers for xapic IPI paths.
x2apic MSR writes/reads don't have serializing semantics and hence need
a serializing instruction or mfence, to make all the previous memory
stores globally visisble before the x2apic msr write for IPI.
Add x2apic_wrmsr_fence() in flush tlb path to x2apic specific paths.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: "steiner@sgi.com" <steiner@sgi.com>
Cc: Nick Piggin <npiggin@suse.de>
LKML-Reference: <1237313814.27006.203.camel@localhost.localdomain>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
asm/highmem.h inclusion is added to use kmap_atomic_prot_pfn()
by commit bb6d59ca92
Now kmap_atomic_prot_pfn is moved to iomap_32.c
by commit dd63fdcc63
So the asm/highmem.h inclusion in iomap_32.c is unnecessary now.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
LKML-Reference: <20090315151517.GA29074@localhost.localdomain>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: new interface
Add a brk()-like allocator which effectively extends the bss in order
to allow very early code to do dynamic allocations. This is better than
using statically allocated arrays for data in subsystems which may never
get used.
The space for brk allocations is in the bss ELF segment, so that the
space is mapped properly by the code which maps the kernel, and so
that bootloaders keep the space free rather than putting a ramdisk or
something into it.
The bss itself, delimited by __bss_stop, ends before the brk area
(__brk_base to __brk_limit). The kernel text, data and bss is reserved
up to __bss_stop.
Any brk-allocated data is reserved separately just before the kernel
pagetable is built, as that code allocates from unreserved spaces
in the e820 map, potentially allocating from any unused brk memory.
Ultimately any unused memory in the brk area is used in the general
kernel memory pool.
Initially the brk space is set to 1MB, which is probably much larger
than any user needs (the largest current user is i386 head_32.S's code
to build the pagetables to map the kernel, which can get fairly large
with a big kernel image and no PSE support). So long as the system
has sufficient memory for the bootloader to reserve the kernel+1MB brk,
there are no bad effects resulting from an over-large brk.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Impact: fix (CONFIG_MAXSMP=y only) boot crash
c032ef60d1 "cpumask: convert
node_to_cpumask_map[] to cpumask_var_t" didn't get this one
conversion. There was a compile warning, but I missed it.
Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Mike Travis <travis@sgi.com>
LKML-Reference: <200903132342.42813.rusty@rustcorp.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
