Nothing arch specific in get/settimeofday. The details of the timeval
conversion varied a little from arch to arch, but all with the same
results.
Also add an extern declaration for sys_tz to linux/time.h because externs
in .c files are fowned upon. I'll kill the externs in various other files
in a sparate patch.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: David S. Miller <davem@davemloft.net> [ sparc bits ]
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Acked-by: Kyle McMartin <kyle@mcmartin.ca>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Grant Grundler <grundler@parisc-linux.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
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>
struct stat / compat_stat is the same on all architectures, so
cp_compat_stat should be, too.
Turns out it is, except that various architectures have slightly and some
high2lowuid/high2lowgid or the direct assignment instead of the
SET_UID/SET_GID that expands to the correct one anyway.
This patch replaces the arch-specific cp_compat_stat implementations with
a common one based on the x86-64 one.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: David S. Miller <davem@davemloft.net> [ sparc bits ]
Acked-by: Kyle McMartin <kyle@mcmartin.ca> [ parisc bits ]
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Using "def_bool n" is pointless, simply using bool here appears more
appropriate.
Further, retaining such options that don't have a prompt and aren't
selected by anything seems also at least questionable.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The SET_PERSONALITY macro is always called with a second argument of 0.
Remove the ibcs argument and the various tests to set the PER_SVR4
personality.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
With intel iommu hardware, we can assign devices to kvm/ia64 guests.
Signed-off-by: Xiantao Zhang <xiantao.zhang@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Using vt-d, kvm guests can be assigned physcial devices, so
this patch introduce a new mmio type (directed mmio)
to handle its mmio access.
Signed-off-by: Xiantao Zhang <xiantao.zhang@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Don't try to do put_page once the entries are mmio.
Set the tag to indicate the mmio space for vmm setting
TLB's memory attribute.
Signed-off-by: Xiantao Zhang <xiantao.zhang@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Moving irq ack notification logic as common, and make
it shared with ia64 side.
Signed-off-by: Xiantao Zhang <xiantao.zhang@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
In Tukwila processor, VT-i has been enhanced in its
implementation, it is often called VT-i2 techonology.
With VTi-2 support, virtulization performance should be
improved. In this patch, we added the related stuff to
support kvm/ia64 for Tukwila processors.
Signed-off-by: Xiantao Zhang <xiantao.zhang@intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
An uniform entry kvm_vps_entry is added for
vps_sync_write/read, vps_resume_handler/guest,
and branches to differnt PAL service according to the offset.
Singed-off-by: Anthony Xu <anthony.xu@intel.com>
Signed-off-by: Xiantao Zhang <xiantao.zhang@intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Two ioctl arch functions are added to set vcpu's smp state.
Signed-off-by: Xiantao Zhang <xiantao.zhang@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
kvm/ia64 uses the virtio drivers to optimize its I/O subsytem.
Signed-off-by: Xiantao Zhang <xiantao.zhang@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Before enabling notify_acked_irq for ia64, leave the related APIs as
nop-op first.
Signed-off-by: Xiantao Zhang <xiantao.zhang@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Initial fix for making sure that we can access percpu variables
in all C code (commit: 10617bbe84)
inadvertantly allocated the memory in the "percpu" section of
the vmlinux ELF executable. This confused kexec/dump.
Signed-off-by: Tony Luck <tony.luck@intel.com>
Currently a SIGTRAP can denote any one of below reasons.
- Breakpoint hit
- H/W debug register hit
- Single step
- Signal sent through kill() or rasie()
Architectures like powerpc/parisc provides infrastructure to demultiplex
SIGTRAP signal by passing down the information for receiving SIGTRAP through
si_code of siginfot_t structure. Here is an attempt is generalise this
infrastructure by extending it to x86 and x86_64 archs.
Signed-off-by: Srinivasa DS <srinivasa@in.ibm.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: akpm@linux-foundation.org
Cc: paulus@samba.org
Cc: linuxppc-dev@ozlabs.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Currently a memory segment in memory map with attribute of EFI_MEMORY_UC
is denoted as "System RAM" in /proc/iomem, while memory of attribute
(EFI_MEMORY_WB|EFI_MEMORY_UC) is also labeled the same.
The kexec utility then includes uncached memory as part of vmcore. The
kdump kernel MCA'ed when it tries to save the vmcore to a disk. A normal
"cached" access may cause MCAs.
This patch would label memory with attribute of EFI_MEMORY_UC only as
"Uncached RAM" so that kexec would know not to include it in the vmcore.
I will submit a separate kexec-tools patch to the kexec list.
Signed-off-by: Jay Lan <jlan@sgi.com>
Acked-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Peter Chubb reported that commit 3463a93def
(Update check_sal_cache_flush to use platform_send_ipi()) broke
Ski because it does not implement IPIs.
Tony Luck suggested we just #ifndef out the call (since the simulator
does not have the SAL bug that this code is attempting to detect and
workaround)
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Commit 4611a77 ("[IA64] fix compile failure with non modular builds")
introduced struct fdesc into asm/elf.h, which duplicates KVM's definition.
Remove the latter to avoid the build error.
Signed-off-by: Jes Sorensen <jes@sgi.com>
Acked-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Make ia64 refrain from clearing a given to-be-offlined CPU's bit in the
cpu_online_mask until it has processed pending irqs. This change
prevents other CPUs from being blindsided by an apparently offline CPU
nevertheless changing globally visible state. Also remove the existing
redundant cpu_clear(cpu, cpu_online_map).
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Error handling code following a kmalloc should free the allocated data.
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Tony Luck <tony.luck@intel.com>
bte.h expects a #define of L1_CACHE_MASK which is currently only
in bte.c. This small patch gets bte.h to include cleanly and makes
BTE_UNALIGNED_COPY not report errors.
Signed-off-by: Robin Holt <holt@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Broke the non modular builds by moving an essential function into
modules.c. Fix this by moving it out again and into asm/sections.h as
an inline. To do this, the definitions of struct fdesc and struct
got_val have been lifted out of modules.c and put in asm/elf.h where
they belong.
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
It was introduced by "vsprintf: add support for '%pS' and '%pF' pointer
formats" in commit 0fe1ef24f7. However,
the current way its coded doesn't work on parisc64. For two reasons: 1)
parisc isn't in the #ifdef and 2) parisc has a different format for
function descriptors
Make dereference_function_descriptor() more accommodating by allowing
architecture overrides. I put the three overrides (for parisc64, ppc64
and ia64) in arch/kernel/module.c because that's where the kernel
internal linker which knows how to deal with function descriptors sits.
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Tony Luck <tony.luck@intel.com>
Acked-by: Kyle McMartin <kyle@mcmartin.ca>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Right now, there is no notifier that is called on a new cpu, before the new
cpu begins processing interrupts/softirqs.
Various kernel function would need that notification, e.g. kvm works around
by calling smp_call_function_single(), rcu polls cpu_online_map.
The patch adds a CPU_STARTING notification. It also adds a helper function
that sends the message to all cpu_chain handlers.
Tested on x86-64.
All other archs are untested. Especially on sparc, I'm not sure if I got
it right.
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch makes dma_alloc_coherent use GFP_DMA at all times. This is
necessary for swiotlb, which requires the callers to set up the gfp
flags properly.
swiotlb_alloc_coherent tries to allocate pages with the gfp flags. If
the allocated memory isn't fit for dev->coherent_dma_mask,
swiotlb_alloc_coherent reserves some of the swiotlb memory area, which
is precious resource. So the callers need to set up the gfp flags
properly.
This patch means that other IA64 IOMMUs' dma_alloc_coherent also use
GFP_DMA. These IOMMUs (e.g. SBA IOMMU) don't need GFP_DMA since they
can map a memory to any address. But IA64's GFP_DMA is large,
generally drivers allocate small memory with dma_alloc_coherent only
at startup. So I chose the simplest way to set up the gfp flags for
swiotlb.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch also includes the required removal of (unused) inclusion of
<asm/a.out.h> <linux/a.out.h>'s in the arch/ code for these
architectures.
[dwmw2: updated for 2.6.27-rc]
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Some ia64 systems produce several repeats of kernel messages like this:
kernel unaligned access to 0xe000000644220466, ip=0xa000000100516fa1
This was tracked to ide code using the __cmd[] field in "struct request"
via the __outsw() function. __cmd[] is a char array, so is not guaranteed
to be properly aligned when accessed as words.
Tested-by: Nishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
CONFIG_SFC=m uses topology_core_siblings() which, for ia64, expects
cpu_core_map to be exported. It is not. This patch exports the needed
symbol.
Maintainers note: This really looks like the wrong thing to do ... it
would be much better for the kernel to export an API to provide
drivers like this with data they need (which in the case of this
driver seems to be an estimate of the effective parallelism available
on the platform). But x86 has exported this forever ... so go with
the flow until such an API is defined.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Robin Holt <holt@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Switch ia64 to the generic compat_sys_old_readdir which is identical
except for slightly better error handling. Also remove sys32_getdents
which already isn't wired up to the syscall table anymore in favour of
compat_sys_getdents.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tony Luck <tony.luck@intel.com>
The code walks all the acpi _CRS methods to see how many windows
to allocate. It then scans them all again to insert_resource()
for each *even if the first scan found that there were none*.
Move the second scan inside the "if (windows)" clause.
Signed-off-by: Tony Luck <tony.luck@intel.com>
Making allmodconfig will break the current build. This patch shrinks
the per_cpu__shadow_flush_counts from 16k to 8k which frees enough space
to allow allmodconfig to successfully complete.
Fixes http://bugzilla.kernel.org/show_bug.cgi?id=11338
Signed-off-by: Robin Holt <holt@sgi.com>
Acked-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Not really a patch as much as a remove this file request. Now that
generic_defconfig supports all the configurations SGI currently supports
and has NR_CPUS and NR_NODES at our largest configurations, we have no
reason to maintain the extra defconfig file.
Signed-off-by: Robin Holt <holt@sgi.com>
Acked-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Jes Sorensen <jes@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Rename KEXEC_CONTROL_CODE_SIZE to KEXEC_CONTROL_PAGE_SIZE, because control
page is used for not only code on some platform. For example in kexec
jump, it is used for data and stack too.
[akpm@linux-foundation.org: unbreak powerpc and arm, finish conversion]
Signed-off-by: Huang Ying <ying.huang@intel.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch changes ia64 to use the new bcd2bin/bin2bcd functions instead
of the obsolete BCD2BIN/BIN2BCD macros.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>
ia64 handles per-cpu variables a litle differently from other architectures
in that it maps the physical memory allocated for each cpu at a constant
virtual address (0xffffffffffff0000). This mapping is not enabled until
the architecture specific cpu_init() function is run, which causes problems
since some generic code is run before this point. In particular when
CONFIG_PRINTK_TIME is enabled, the boot cpu will trap on the access to
per-cpu memory at the first printk() call so the boot will fail without
the kernel printing anything to the console.
Fix this by allocating percpu memory for cpu0 in the kernel data section
and doing all initialization to enable percpu access in head.S before
calling any generic code.
Other cpus must take care not to access per-cpu variables too early, but
their code path from start_secondary() to cpu_init() is all in arch/ia64
Signed-off-by: Tony Luck <tony.luck@intel.com>
This patch changes the generic_defconfig so it works on all sn2
platforms I have access to. There is only one support configuration
which was not tested and that configuration is only a combination of two
tested configurations. With this patchset applied, a generic kernel can
be booted on either a RHEL 5.2, RHEL5.3, or SLES10 SP1 root and operate.
All features needed by SGI's ProPack are also working. I have not
tested all features of RHEL or SLES, but they do at least boot.
Signed-off-by: Robin Holt <holt@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
This patch updates the generic_defconfig for 2.6.27-rc1 by simply doing
a make oldconfig and holding down the carriage return.
Signed-off-by: Robin Holt <holt@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
ia64 has compiled with NR_CPUS=4096 for a couple releases, just forgot
to update Kconfig to allow it.
Signed-off-by: Robin Holt <holt@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
arch/ia64/kernel/vmlinux.lds is a generated file. Tell
git to ignore it.
Signed-off-by: Robin Holt <holt@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Recent kernels are not booting on some HP systems (though
it does boot on others). James and Willy reported the
problem. James did the bisection to find the commit
that caused the problem:
498c517047.
[IA64] pvops: paravirtualize ivt.S
Two instructions were wrongly paravirtualized such that
_FROM_ macro had been used where _TO_ was intended
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: "Wilcox, Matthew R" <matthew.r.wilcox@intel.com>
Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Tony Luck <tony.luck@intel.com>
After moving the the include files there were a few clean-ups:
1) Some files used #include <asm-ia64/xyz.h>, changed to <asm/xyz.h>
2) Some comments alerted maintainers to look at various header files to
make matching updates if certain code were to be changed. Updated these
comments to use the new include paths.
3) Some header files mentioned their own names in initial comments. Just
deleted these self references.
Signed-off-by: Tony Luck <tony.luck@intel.com>
This series of patches adds a driver for the SGI UV GRU. The driver is
still in development but it currently compiles for both x86_64 & IA64.
All simple regression tests pass on IA64. Although features remain to be
added, I'd like to start the process of getting the driver into the
kernel. Additional kernel drivers will depend on services provide by the
GRU driver.
The GRU is a hardware resource located in the system chipset. The GRU
contains memory that is mmaped into the user address space. This memory
is used to communicate with the GRU to perform functions such as
load/store, scatter/gather, bcopy, AMOs, etc. The GRU is directly
accessed by user instructions using user virtual addresses. GRU
instructions (ex., bcopy) use user virtual addresses for operands.
The GRU contains a large TLB that is functionally very similar to
processor TLBs. Because the external contains a TLB with user virtual
address, it requires callouts from the core VM system when certain types
of changes are made to the process page tables. There are several MMUOPS
patches currently being discussed but none has been accepted into the
kernel. The GRU driver is built using version V18 from Andrea Arcangeli.
This patch:
Contains the definitions of the hardware GRU data structures that are used
by the driver to manage the GRU.
[akpm@linux-foundation;org: export hpage_shift]
Signed-off-by: Jack Steiner <steiner@sgi.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is a call to local_irq_restore in the normal exit case, so it would
seem that there should be one on an error return as well.
The semantic patch that finds this problem is as follows:
(http://www.emn.fr/x-info/coccinelle/)
// <smpl>
@@
expression l;
expression E,E1,E2;
@@
local_irq_save(l);
... when != local_irq_restore(l)
when != spin_unlock_irqrestore(E,l)
when any
when strict
(
if (...) { ... when != local_irq_restore(l)
when != spin_unlock_irqrestore(E1,l)
+ local_irq_restore(l);
return ...;
}
|
if (...)
+ {local_irq_restore(l);
return ...;
+ }
|
spin_unlock_irqrestore(E2,l);
|
local_irq_restore(l);
)
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Avi Kivity <avi@qumranet.com>
This extends wait_task_inactive() with a new argument so it can be used in
a "soft" mode where it will check for the task changing state unexpectedly
and back off. There is no change to existing callers. This lays the
groundwork to allow robust, noninvasive tracing that can try to sample a
blocked thread but back off safely if it wakes up.
Signed-off-by: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add per-device dma_mapping_ops support for CONFIG_X86_64 as POWER
architecture does:
This enables us to cleanly fix the Calgary IOMMU issue that some devices
are not behind the IOMMU (http://lkml.org/lkml/2008/5/8/423).
I think that per-device dma_mapping_ops support would be also helpful for
KVM people to support PCI passthrough but Andi thinks that this makes it
difficult to support the PCI passthrough (see the above thread). So I
CC'ed this to KVM camp. Comments are appreciated.
A pointer to dma_mapping_ops to struct dev_archdata is added. If the
pointer is non NULL, DMA operations in asm/dma-mapping.h use it. If it's
NULL, the system-wide dma_ops pointer is used as before.
If it's useful for KVM people, I plan to implement a mechanism to register
a hook called when a new pci (or dma capable) device is created (it works
with hot plugging). It enables IOMMUs to set up an appropriate
dma_mapping_ops per device.
The major obstacle is that dma_mapping_error doesn't take a pointer to the
device unlike other DMA operations. So x86 can't have dma_mapping_ops per
device. Note all the POWER IOMMUs use the same dma_mapping_error function
so this is not a problem for POWER but x86 IOMMUs use different
dma_mapping_error functions.
The first patch adds the device argument to dma_mapping_error. The patch
is trivial but large since it touches lots of drivers and dma-mapping.h in
all the architecture.
This patch:
dma_mapping_error() doesn't take a pointer to the device unlike other DMA
operations. So we can't have dma_mapping_ops per device.
Note that POWER already has dma_mapping_ops per device but all the POWER
IOMMUs use the same dma_mapping_error function. x86 IOMMUs use device
argument.
[akpm@linux-foundation.org: fix sge]
[akpm@linux-foundation.org: fix svc_rdma]
[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: fix bnx2x]
[akpm@linux-foundation.org: fix s2io]
[akpm@linux-foundation.org: fix pasemi_mac]
[akpm@linux-foundation.org: fix sdhci]
[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: fix sparc]
[akpm@linux-foundation.org: fix ibmvscsi]
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Muli Ben-Yehuda <muli@il.ibm.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Avi Kivity <avi@qumranet.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently list of kretprobe instances are stored in kretprobe object (as
used_instances,free_instances) and in kretprobe hash table. We have one
global kretprobe lock to serialise the access to these lists. This causes
only one kretprobe handler to execute at a time. Hence affects system
performance, particularly on SMP systems and when return probe is set on
lot of functions (like on all systemcalls).
Solution proposed here gives fine-grain locks that performs better on SMP
system compared to present kretprobe implementation.
Solution:
1) Instead of having one global lock to protect kretprobe instances
present in kretprobe object and kretprobe hash table. We will have
two locks, one lock for protecting kretprobe hash table and another
lock for kretporbe object.
2) We hold lock present in kretprobe object while we modify kretprobe
instance in kretprobe object and we hold per-hash-list lock while
modifying kretprobe instances present in that hash list. To prevent
deadlock, we never grab a per-hash-list lock while holding a kretprobe
lock.
3) We can remove used_instances from struct kretprobe, as we can
track used instances of kretprobe instances using kretprobe hash
table.
Time duration for kernel compilation ("make -j 8") on a 8-way ppc64 system
with return probes set on all systemcalls looks like this.
cacheline non-cacheline Un-patched kernel
aligned patch aligned patch
===============================================================================
real 9m46.784s 9m54.412s 10m2.450s
user 40m5.715s 40m7.142s 40m4.273s
sys 2m57.754s 2m58.583s 3m17.430s
===========================================================
Time duration for kernel compilation ("make -j 8) on the same system, when
kernel is not probed.
=========================
real 9m26.389s
user 40m8.775s
sys 2m7.283s
=========================
Signed-off-by: Srinivasa DS <srinivasa@in.ibm.com>
Signed-off-by: Jim Keniston <jkenisto@us.ibm.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Christoph Hellwig