This update cleans up the code and simplifies the xmit routines to
share some of the code. It also brings tap up to date to do scatter
gather and TSO on transmit. The result is ... drum roll... 4.5Gbit+
on iperf on my laptop. As a reference QEMU+kvm with all bells and
whistles does under 1GBit and
From: Anton Ivanov
UBD at present is extremely slow because it handles only
one request at a time in the IO thread and IRQ handler.
The single request at a time is replaced by handling multiple
requests as well as necessary workarounds for short reads/writes.
Resulting performance improvement i
Hi!
Am 18.11.2015 um 14:32 schrieb Lorenzo Colitti:
> On Wed, Nov 18, 2015 at 5:06 PM, Richard Weinberger wrote:
>>
>>> That command line doesn't work, but if you remove the -lrt and put it
>>> at the end of the line, it starts working. Is the order significant?
>>> Or is it a bug in GCC's comman
On Wed, Nov 18, 2015 at 5:06 PM, Richard Weinberger wrote:
>
> > That command line doesn't work, but if you remove the -lrt and put it
> > at the end of the line, it starts working. Is the order significant?
> > Or is it a bug in GCC's command line parsing?
>
> The order matters.
> -lrt has to be
Am 18.11.2015 um 08:10 schrieb Lorenzo Colitti:
> On Wed, Nov 18, 2015 at 4:00 PM, Anton Ivanov
> wrote:
>> It is.
>>
>> You need -lrt to link in HR timers. However, the original patch should add
>> that to the library list. I need to understand why it does not in the dm
>> tree.
>
> I noticed th
On Wed, Nov 18, 2015 at 4:00 PM, Anton Ivanov
wrote:
> It is.
>
> You need -lrt to link in HR timers. However, the original patch should add
> that to the library list. I need to understand why it does not in the dm
> tree.
I noticed that command already does contain "-lrt", just in a
different p
On 18/11/15 01:20, Lorenzo Colitti wrote:
> On Sat, Nov 7, 2015 at 6:56 AM, Richard Weinberger wrote:
>> Am 02.11.2015 um 17:16 schrieb Anton Ivanov:
>>> Background: UML is using an obsolete itimer call for
>>> all timers and "polls" for kernel space timer firing
>>> in its userspace portion res
On Sat, Nov 7, 2015 at 6:56 AM, Richard Weinberger wrote:
>
> Am 02.11.2015 um 17:16 schrieb Anton Ivanov:
> > Background: UML is using an obsolete itimer call for
> > all timers and "polls" for kernel space timer firing
> > in its userspace portion resulting in a long list
> > of bugs and incorre
Hi!
Am 07.11.2015 um 11:29 schrieb Anton Ivanov:
> Cool,
>
> Is there a tree I can pull so I can have the next one (the epoll based IRQ
> controller) incremental?
Sure, it is in uml's next:
https://git.kernel.org/cgit/linux/kernel/git/rw/uml.git/log/?h=linux-next
Thanks,
//richard
---
Cool,
Is there a tree I can pull so I can have the next one (the epoll based
IRQ controller) incremental?
A.
On 06/11/15 21:56, Richard Weinberger wrote:
> Am 02.11.2015 um 17:16 schrieb Anton Ivanov:
>> Background: UML is using an obsolete itimer call for
>> all timers and "polls" for kernel s
Am 02.11.2015 um 17:16 schrieb Anton Ivanov:
> Background: UML is using an obsolete itimer call for
> all timers and "polls" for kernel space timer firing
> in its userspace portion resulting in a long list
> of bugs and incorrect behaviour(s). It also uses
> ITIMER_VIRTUAL for its timer which resu
Am 29.10.2015 um 16:30 schrieb Saurabh Sengar:
> since GFP_KERNEL with GFP_ATOMIC while spinlock is held,
> as code while holding a spinlock should be atomic.
> GFP_KERNEL may sleep and can cause deadlock,
> where as GFP_ATOMIC may fail but certainly avoids deadlockdex
> f70dd54..d898f6c 100644
>
Am 03.11.2015 8:11 vorm. schrieb Anton Ivanov :
>
> On 02/11/15 22:13, Anton Ivanov wrote:
> > On 02/11/15 21:50, Richard Weinberger wrote:
> >> Am 02.11.2015 um 17:16 schrieb Anton Ivanov:
> >>> -void idle_sleep(unsigned long long nsecs)
> >>> +/**
> >>> + * os_idle_sleep() - sleep for a giv
On 02/11/15 22:13, Anton Ivanov wrote:
> On 02/11/15 21:50, Richard Weinberger wrote:
>> Am 02.11.2015 um 17:16 schrieb Anton Ivanov:
>>> -void idle_sleep(unsigned long long nsecs)
>>> +/**
>>> + * os_idle_sleep() - sleep for a given time of nsecs
>>> + * @nsecs: nanoseconds to sleep
>>> + */
>>> +
On 02/11/15 21:50, Richard Weinberger wrote:
> Am 02.11.2015 um 17:16 schrieb Anton Ivanov:
>> -void idle_sleep(unsigned long long nsecs)
>> +/**
>> + * os_idle_sleep() - sleep for a given time of nsecs
>> + * @nsecs: nanoseconds to sleep
>> + */
>> +void os_idle_sleep(unsigned long long nsecs)
>>
Am 02.11.2015 um 17:16 schrieb Anton Ivanov:
> -void idle_sleep(unsigned long long nsecs)
> +/**
> + * os_idle_sleep() - sleep for a given time of nsecs
> + * @nsecs: nanoseconds to sleep
> + */
> +void os_idle_sleep(unsigned long long nsecs)
> {
> struct timespec ts;
>
> - /*
> -
Background: UML is using an obsolete itimer call for
all timers and "polls" for kernel space timer firing
in its userspace portion resulting in a long list
of bugs and incorrect behaviour(s). It also uses
ITIMER_VIRTUAL for its timer which results in the
timer being dependent on it running and the
Some architecture would like to be triggered when a memory area is moved
through the mremap system call.
This patch is introducing a new arch_remap mm hook which is placed in the
path of mremap, and is called before the old area is unmapped (and the
arch_unmap hook is called).
The architectures w
CRIU is recreating the process memory layout by remapping the checkpointee
memory area on top of the current process (criu). This includes remapping
the vDSO to the place it has at checkpoint time.
However some architectures like powerpc are keeping a reference to the vDSO
base address to build th
On 26/03/2015 19:55, Ingo Molnar wrote:
>
> * Laurent Dufour wrote:
>
>> +{
>> +unsigned long vdso_end, vdso_start;
>> +
>> +if (!mm->context.vdso_base)
>> +return;
>> +vdso_start = mm->context.vdso_base;
>> +
>> +#ifdef CONFIG_PPC64
>> +/* Calling is_32bit_task() imp
* Laurent Dufour wrote:
> +{
> + unsigned long vdso_end, vdso_start;
> +
> + if (!mm->context.vdso_base)
> + return;
> + vdso_start = mm->context.vdso_base;
> +
> +#ifdef CONFIG_PPC64
> + /* Calling is_32bit_task() implies that we are dealing with the
> + * curre
Some processes (CRIU) are moving the vDSO area using the mremap system
call. As a consequence the kernel reference to the vDSO base address is
no more valid and the signal return frame built once the vDSO has been
moved is not pointing to the new sigreturn address.
This patch handles vDSO remappin
Add a kmsg_dumper, that dumps the kmsg buffer to stdout, when no console
is available. This an enables the printing of early panic() calls
triggered in uml_postsetup().
When a panic() call happens so early in the UML kernel no
earlyprintk/console is available yet, but with a kmsg_dumper in place
t
atomic_notifier_chain_register() and uml_postsetup() do call kernel code
that rely on the "current" kernel macro and a valid task_struct resp.
thread_info struct. Give those functions a valid stack by moving
uml_postsetup() in the init_thread stack. This moves enables a panic()
call in this early
From: Anton Ivanov
If the ubd is asynchronous the amount of time uml will spend
fsync-ing on FLUSH is unpredictable. There are bits in the upper fs
layers that really dislike this. Replacing fsync() with an
async flush request via sync_file_range mitigates this (somewhat),
improves performance si
From: Anton Ivanov
This patch adds an extra timer source which has correct timing
and uses an up-to-date OS API and.
Results - correct kernel behaviour on timer related tasks.
1. Improvement in network performance (TCP state machines
are now fed correct time).
2. Correct QoS and traffic
From: Anton Ivanov
This transport allows a UML to connect to another UML local
or remote, the Linux host or any other network device running
the industry standard Ethernet over GRE protocol. The transport
supports all features of RFC 2784.
The transport supports a common set of features with the
From: Anton Ivanov
Support for multi-packet vector IO - multiple packets
read in one syscall and (optionally) written in one syscall.
Support for (optional) queueing on EAGAIN/ENOBUFS - applies
only to socket transports. Sorry TAP, -EYOULOSE - it will remain
slower than any so
From: Anton Ivanov
1. Minimum kernel 2.5.44
2. No "walk the list" lookups for received IRQs - immediate identification
of the correct handler to invoke
3. Full set of IRQ semantics - edge, level, read, write
3.1. Write is now a *REAL* write - so if you (ab)use the
write to signify NONE (a
From: Anton Ivanov
The epoll based controller has real (not emulated) edge and
level semantics and the edge/level is handled by epoll. There
is no toggling of the poll set any more, thus it is removed
throughout
Signed-off-by: Anton Ivanov
---
arch/um/drivers/chan_kern.c |2 --
arch/um
From: Anton Ivanov
The use of the seek()/read() and seek()/write() is a terminal
disease on NUMA. Intense use of this on shared files (f.e.
the master for a COW image) can cause anything up to and including
killing CPUs on unhandled NMIs.
This patch deals with this UML major issue (and one of UM
From: Anton Ivanov
socketpair() is a better IPC choice for lots of small requests
as it allows deeper (and configurable) queues than pipe()
As a result UBD will process nearly all of the requests submitted
to it instead of bouncing a significant percentage under load
Signed-off-by: Anton Ivanov
From: Anton Ivanov
Obvious performance optimization - it is not necessary
to read the requests one at a time in the IRQ handler
Signed-off-by: Anton Ivanov
---
arch/um/drivers/ubd_kern.c | 29 ++---
1 file changed, 22 insertions(+), 7 deletions(-)
diff --git a/arch/u
From: Anton Ivanov
This is an alternative to the well known pcap transport.
In the absense of special hardware support pcap is slow,
guaranteed to be slow and with significant penalties on
NUMA/SMP systems due to the timestamping of every packet.
This transport does not incur any of these times
On Thu, 2014-07-24 at 13:56 -0700, Andy Lutomirski wrote:
> The core mm code will provide a default gate area based on
> FIXADDR_USER_START and FIXADDR_USER_END if
> !defined(__HAVE_ARCH_GATE_AREA) && defined(AT_SYSINFO_EHDR).
>
> This default is only useful for ia64. arm64, ppc, s390, sh, tile,
The core mm code will provide a default gate area based on
FIXADDR_USER_START and FIXADDR_USER_END if
!defined(__HAVE_ARCH_GATE_AREA) && defined(AT_SYSINFO_EHDR).
This default is only useful for ia64. arm64, ppc, s390, sh, tile,
64-bit UML, and x86_32 have their own code just to disable it. arm,
Normalize global variables exported by vmlinux.lds to conform usage
guidelines from include/asm-generic/sections.h.
1) Use _text to mark the start of the kernel image including the head
text, and _stext to mark the start of the .text section.
2) Export mandatory global variables __bss_stop.
3) Adj
Prepare for removing num_physpages and simplify mem_init().
Signed-off-by: Jiang Liu
Cc: Jeff Dike
Cc: Richard Weinberger
Cc: user-mode-linux-devel@lists.sourceforge.net
Cc: linux-ker...@vger.kernel.org
---
arch/um/kernel/mem.c |4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff
These are the simple ones.
File systems that use generic_file_aio_read() and generic_file_aio_write()
can trivially support generic_file_read_iter() and generic_file_write_iter().
This patch adds those file_operations for 9p, adfs, affs, bfs, exofs, ext2,
ext3, fat, hfs, hfsplus, hostfs, hpfs, jf
It decreases code size as well:
textdata bss dec hex filename
15767 0 8 157753d9f lib/vsprintf.o-before
15735 0 8 157433d7f lib/vsprintf.o-TOLOWER
Signed-off-by: André Goddard Rosa
Acked-by: Frederic Weisbecker
---
lib/vsprintf.c | 15
Makes use of skip_spaces() defined in lib/string.c for removing leading
spaces from strings all over the tree.
Also, while at it, if we see (*str && isspace(*str)), we can be sure to
remove the first condition (*str) as the second one (isspace(*str)) also
evaluates to 0 whenever *str == 0, making
Most relevant complaints were addressed.
Signed-off-by: André Goddard Rosa
Acked-by: Frederic Weisbecker
---
lib/vsprintf.c | 186 ++--
1 files changed, 99 insertions(+), 87 deletions(-)
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 403
This patch reduces lib.a code size by 173 bytes on my Core 2 with gcc 4.4.1
even considering that it exports a newly defined function skip_spaces()
to drivers:
textdata bss dec hex filename
64867 840 592 66299 102fb (TOTALS-lib.a-before)
Change "" to "(null)" and make it a static const char[] hoping that
the compiler will make null_str a label to a read-only area containing it.
See:
http://people.redhat.com/drepper/dsohowto.pdf part 2.4.2
http://udrepper.livejournal.com/13851.html
http://udrepper.livejournal.com/15119.html
Signed
While at it, use tabs to indent the comments.
Signed-off-by: André Goddard Rosa
---
include/linux/ctype.h |2 +-
lib/ctype.c | 50
2 files changed, 26 insertions(+), 26 deletions(-)
diff --git a/include/linux/ctype.h b/include/lin
The difference between simple_strtoul() and simple_strtoull() is just
the size of the variable used to keep track of the sum of characters
converted to numbers:
unsigned long simple_strtoul() {...}
unsigned long long simple_strtoull(){...}
Both are same size (8 bytes) on my Core 2/gcc 4.4.1.
Over
> > Also, while at it, if we see (*str && isspace(*str)), we can be sure to
> > remove the first condition (*str) as the second one (isspace(*str)) also
> > evaluates to 0 whenever *str == 0, making it redundant. In other words,
> > "a char equals zero is never a space".
I tried the following sema
On Sat, Nov 07, 2009 at 01:16:20PM -0200, André Goddard Rosa wrote:
> Makes use of skip_spaces() defined in lib/string.c for removing leading
> spaces from strings all over the tree.
>
> Also, while at it, if we see (*str && isspace(*str)), we can be sure to
> remove the first condition (*str) as
It decreases code size:
textdata bss dec hex filename
15719 0 8 157273d6f lib/vsprintf.o-before
15543 0 8 155513cbf lib/vsprintf.o-after
Signed-off-by: André Goddard Rosa
Acked-by: Frederic Weisbecker
---
lib/vsprintf.c | 19 +
Cleanup by moving variables closer to the scope where they're used in fact.
Also, remove unneeded ones.
Signed-off-by: André Goddard Rosa
Acked-by: Frederic Weisbecker
---
lib/vsprintf.c | 64 ---
1 files changed, 28 insertions(+), 36 deleti
Signed-off-by: André Goddard Rosa
Acked-by: Frederic Weisbecker
---
lib/vsprintf.c | 10 ++
1 files changed, 6 insertions(+), 4 deletions(-)
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 002f462..403e835 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -1445,13 +1445,15 @@ do
On the following sentence:
while (*s && isspace(*s))
s++;
If *s == 0, isspace() evaluates to ((_ctype[*s] & 0x20) != 0), which
evaluates to ((0x08 & 0x20) != 0) which equals to 0 as well.
If *s == 1, we depend on isspace() result anyway.
In other words, "a char equals zero is never a
No functional change, just refactor the code so that it avoid checking
"if (hi)" two times in a sequence, taking advantage of previous check made.
It also reduces code size:
textdata bss dec hex filename
15735 0 8 157433d7f lib/vsprintf.o-before
15719
On Sat, 7 Nov 2009 13:16:18 -0200
André Goddard Rosa wrote:
> On the following sentence:
> while (*s && isspace(*s))
> s++;
Looks fine but for one thing: it's actually shorter inline than moved
into /lib so at the very least it should be a header inline not a
function call.
Second
... so that strlen() iterates over a smaller string comprising of the
remaining characters only.
Signed-off-by: André Goddard Rosa
---
lib/string.c |4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/lib/string.c b/lib/string.c
index d9a51d5..cf86eab 100644
--- a/lib/stri
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