This is the commit that porting the perf for nds32.
1.Raw event:
The raw events start with 'r'.
Usage:
perf stat -e rXYZ ./app
X: the index of performance counter.
YZ: the index(convert to hexdecimal) of events
Example:
'perf stat -e r101 ./app' means the counter 1 will count the instruction
event.
The index of counter and events can be found in
"Andes System Privilege Architecture Version 3 Manual".
Or you can perform the 'perf list' to find the symbolic name of raw events.
2.Perf mmap2:
Fix unexpected perf mmap2() page fault
When the mmap2() called by perf application,
you will encounter such condition:"failed to write."
With return value -EFAULT
This is due to the page fault caused by "reading" buffer
from the mapped legal address region to write to the descriptor.
The page_fault handler will get a VM_FAULT_SIGBUS return value,
which should not happens here.(Due to this is a read request.)
You can refer to kernel/events/core.c:perf_mmap_fault(...)
If "(vmf->pgoff && (vmf->flags & FAULT_FLAG_WRITE))" is evaluated
as true, you will get VM_FAULT_SIGBUS as return value.
However, this is not an write request. The flags which indicated
why the page fault happens is wrong.
Furthermore, NDS32 SPAv3 is not able to detect it is read or write.
It only know either it is instruction fetch or data access.
Therefore, by removing the wrong flag assignment(actually, the hardware
is not able to show the reason), we can fix this bug.
3.Perf multiple events map to same counter.
When there are multiple events map to the same counter, the counter
counts inaccurately. This is because each counter only counts one event
in the same time.
So when there are multiple events map to same counter, they have to take
turns in each context.
There are two solution:
1. Print the error message when multiple events map to the same counter.
But print the error message would let the program hang in loop. The ltp
(linux test program) would be failed when the program hang in loop.
2. Don't print the error message, the ltp would pass. But the user need to
have the knowledge that don't count the events which map to the same
counter, or the user will get the inaccurate results.
We choose method 2 for the solution
Signed-off-by: Nickhu <nickhu@andestech.com>
Acked-by: Greentime Hu <greentime@andestech.com>
Signed-off-by: Greentime Hu <greentime@andestech.com>
Use new return type vm_fault_t for fault handler. For now, this is just
documenting that the function returns a VM_FAULT value rather than an
errno. Once all instances are converted, vm_fault_t will become a
distinct type.
Ref-> commit 1c8f422059 ("mm: change return type to vm_fault_t")
In this patch all the caller of handle_mm_fault() are changed to return
vm_fault_t type.
Link: http://lkml.kernel.org/r/20180617084810.GA6730@jordon-HP-15-Notebook-PC
Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: James Hogan <jhogan@kernel.org>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: James E.J. Bottomley <jejb@parisc-linux.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: David S. Miller <davem@davemloft.net>
Cc: Richard Weinberger <richard@nod.at>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "Levin, Alexander (Sasha Levin)" <alexander.levin@verizon.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Filling in struct siginfo before calling force_sig_info a tedious and
error prone process, where once in a great while the wrong fields
are filled out, and siginfo has been inconsistently cleared.
Simplify this process by using the helper force_sig_fault. Which
takes as a parameters all of the information it needs, ensures
all of the fiddly bits of filling in struct siginfo are done properly
and then calls force_sig_info.
In short about a 5 line reduction in code for every time force_sig_info
is called, which makes the calling function clearer.
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Acked-by: Vincent Chen <deanbo422@gmail.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Call clear_siginfo to ensure every stack allocated siginfo is properly
initialized before being passed to the signal sending functions.
Note: It is not safe to depend on C initializers to initialize struct
siginfo on the stack because C is allowed to skip holes when
initializing a structure.
The initialization of struct siginfo in tracehook_report_syscall_exit
was moved from the helper user_single_step_siginfo into
tracehook_report_syscall_exit itself, to make it clear that the local
variable siginfo gets fully initialized.
In a few cases the scope of struct siginfo has been reduced to make it
clear that siginfo siginfo is not used on other paths in the function
in which it is declared.
Instances of using memset to initialize siginfo have been replaced
with calls clear_siginfo for clarity.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
This patch includes page fault handler, mmap and fixup implementations.
Signed-off-by: Vincent Chen <vincentc@andestech.com>
Signed-off-by: Greentime Hu <greentime@andestech.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Nickhu