2's compliment.
The 2's compliment transform is done so a "count down" sampling interval
can be converted into a "count up" PMC value. a 2's complimented 'count down'
value is written to the PMC counter; then the read-back counter is reverted
via another 2's compliment.
PR: kern/121660
Reviewed by: jkoshy
Approved by: jkoshy
MFC after: 1 week
conjuction with 'thread' argument passing which is always curthread.
Remove the unuseful extra-argument and pass explicitly curthread to lower
layer functions, when necessary.
KPI results broken by this change, which should affect several ports, so
version bumping and manpage update will be further committed.
Tested by: kris, pho, Diego Sardina <siarodx at gmail dot com>
Remove this argument and pass curthread directly to underlying
VOP_LOCK1() VFS method. This modify makes the code cleaner and in
particular remove an annoying dependence helping next lockmgr() cleanup.
KPI results, obviously, changed.
Manpage and FreeBSD_version will be updated through further commits.
As a side note, would be valuable to say that next commits will address
a similar cleanup about VFS methods, in particular vop_lock1 and
vop_unlock.
Tested by: Diego Sardina <siarodx at gmail dot com>,
Andrea Di Pasquale <whyx dot it at gmail dot com>
Intel CPUs with family 0x6, model 0xE and later (i.e., Intel Core(TM))
have a PMC architecture that differs somewhat from previous CPUs in
family 0x6. Even though the basic programming model is similar, the
documented set of legal values that may be loaded into their PMC MSRs
differs from that of the previous PMCs in family 0x6 and reusing bit
values valid for the older PMCs could result in undefined behaviour in
the general case.
to kproc_xxx as they actually make whole processes.
Thos makes way for us to add REAL kthread_create() and friends
that actually make theads. it turns out that most of these
calls actually end up being moved back to the thread version
when it's added. but we need to make this cosmetic change first.
I'd LOVE to do this rename in 7.0 so that we can eventually MFC the
new kthread_xxx() calls.
- Use thread_lock() rather than sched_lock for per-thread scheduling
sychronization.
- Use the per-process spinlock rather than the sched_lock for per-process
scheduling synchronization.
Tested by: kris, current@
Tested on: i386, amd64, ULE, 4BSD, libthr, libkse, PREEMPTION, etc.
Discussed with: kris, attilio, kmacy, jhb, julian, bde (small parts each)
Group mutexes used in hwpmc(4) into 3 "types" in the sense of
witness(4):
- leaf spin mutexes---only one of these should be held at a time,
so these mutexes are specified as belonging to a single witness
type "pmc-leaf".
- `struct pmc_owner' descriptors are protected by a spin mutex of
witness type "pmc-owner-proc". Since we call wakeup_one() while
holding these mutexes, the witness type of these mutexes needs
to dominate that of "sleepq chain" mutexes.
- logger threads use a sleep mutex, of type "pmc-sleep".
Submitted by: wkoszek (earlier patch)
specific privilege names to a broad range of privileges. These may
require some future tweaking.
Sponsored by: nCircle Network Security, Inc.
Obtained from: TrustedBSD Project
Discussed on: arch@
Reviewed (at least in part) by: mlaier, jmg, pjd, bde, ceri,
Alex Lyashkov <umka at sevcity dot net>,
Skip Ford <skip dot ford at verizon dot net>,
Antoine Brodin <antoine dot brodin at laposte dot net>
with other commonly used sysctl name spaces, rather than declaring them
all over the place.
MFC after: 1 month
Sponsored by: nCircle Network Security, Inc.
if the specified priority is zero. This avoids a race where the calling
thread could read a snapshot of it's current priority, then a different
thread could change the first thread's priority, then the original thread
would call sched_prio() inside msleep() undoing the change made by the
second thread. I used a priority of zero as no thread that calls msleep()
or tsleep() should be specifying a priority of zero anyway.
The various places that passed 'curthread->td_priority' or some variant
as the priority now pass 0.
Kernel changes:
Inform hwpmc of executable objects brought into the system by
kldload() and mmap(), and of their removal by kldunload() and
munmap(). A helper function linker_hwpmc_list_objects() has been
added to "sys/kern/kern_linker.c" and is used by hwpmc to retrieve
the list of currently loaded kernel modules.
The unused `MAPPINGCHANGE' event has been deprecated in favour
of separate `MAP_IN' and `MAP_OUT' events; this change reduces
space wastage in the log.
Bump the hwpmc's ABI version to "2.0.00". Teach hwpmc(4) to
handle the map change callbacks.
Change the default per-cpu sample buffer size to hold
32 samples (up from 16).
Increment __FreeBSD_version.
libpmc(3) changes:
Update libpmc(3) to deal with the new events in the log file; bring
the pmclog(3) manual page in sync with the code.
pmcstat(8) changes:
Introduce new options to pmcstat(8): "-r" (root fs path), "-M"
(mapfile name), "-q"/"-v" (verbosity control). Option "-k" now
takes a kernel directory as its argument but will also work with
the older invocation syntax.
Rework string handling in pmcstat(8) to use an opaque type for
interned strings. Clean up ELF parsing code and add support for
tracking dynamic object mappings reported by a v2.0.00 hwpmc(4).
Report statistics at the end of a log conversion run depending
on the requested verbosity level.
Reviewed by: jhb, dds (kernel parts of an earlier patch)
Tested by: gallatin (earlier patch)
debugging message if the flag PMC_F_OLDVALUE was specified in the
PMC_OP_RW request being acted upon. This should fix Coverity bug
CID 671.
Found by: Coverity Prevent
MFC after: 3 weeks
'buffers' pending NMIs from multiple interrupting PMCs and delivers
them serially.
Reported by: Olivier Crameri <olivier.crameri@epfl.ch>
MFC after: 3 days
specifies a PMC capability (e.g., sampling) that is not supported
by hardware. Return EINVAL early if the PMC class passed in is
not recognized.
MFC after: 3 days
was not compiled with 'options HWPMC_HOOKS' or if the compiled-in
version numbers of the kernel and module are out of sync.
Reported by: cracauer
MFC after: 3 days
variables rather than void * variables. This makes it easier and simpler
to get asm constraints and volatile keywords correct.
MFC after: 3 days
Tested on: i386, alpha, sparc64
Compiled on: ia64, powerpc, amd64
Kernel toolchain busted on: arm
- Update driver interrupt statistics correctly.
sys/sys/pmc.h, sys/dev/hwpmc/hwpmc_mod.c:
- Fix a bug affecting debug printfs.
- Move the 'stalled' flag from being in a bit in the
'pm_flags' field of a 'struct pmc' to a field of its own in the
same structure. This flag is updated from the NMI handler and
keeping it separate makes it easier to avoid races with other
parts of the code.
sys/dev/hwpmc/hwpmc_logging.c:
- Do arithmetic with 'uintptr_t' types rather that casting
to and from 'char *'.
Approved by: re (scottl)
- Allow libpmc(3) to support P4/EMT64 PMCs on the amd64 architecture
and AMD K8 PMCs on the i386. [2]
Submitted by: ps [1]
Pointy hat: myself [2]
Approved by: re (scottl)
- pmcstat(8) gprof output mode fixes:
lib/libpmc/pmclog.{c,h}, sys/sys/pmclog.h:
+ Add a 'is_usermode' field to the PMCLOG_PCSAMPLE event
+ Add an 'entryaddr' field to the PMCLOG_PROCEXEC event,
so that pmcstat(8) can determine where the runtime loader
/libexec/ld-elf.so.1 is getting loaded.
sys/kern/kern_exec.c:
+ Use a local struct to group the entry address of the image being
exec()'ed and the process credential changed flag to the exec
handling hook inside hwpmc(4).
usr.sbin/pmcstat/*:
+ Support "-k kernelpath", "-D sampledir".
+ Implement the ELF bits of 'gmon.out' profile generation in a new
file "pmcstat_log.c". Move all log related functions to this
file.
+ Move local definitions and prototypes to "pmcstat.h"
- Other bug fixes:
+ lib/libpmc/pmclog.c: correctly handle EOF in pmclog_read().
+ sys/dev/hwpmc_mod.c: unconditionally log a PROCEXIT event to all
attached PMCs when a process exits.
+ sys/sys/pmc.h: correct a function prototype.
+ Improve usage checks in pmcstat(8).
Approved by: re (blanket hwpmc)
- Implement sampling modes and logging support in hwpmc(4).
- Separate MI and MD parts of hwpmc(4) and allow sharing of
PMC implementations across different architectures.
Add support for P4 (EMT64) style PMCs to the amd64 code.
- New pmcstat(8) options: -E (exit time counts) -W (counts
every context switch), -R (print log file).
- pmc(3) API changes, improve our ability to keep ABI compatibility
in the future. Add more 'alias' names for commonly used events.
- bug fixes & documentation.
Have pmcstat(8) and pmccontrol(8) use these APIs.
Return PMC class-related constants (PMC widths and capabilities)
with the OP GETCPUINFO call leaving OP PMCINFO to return only the
dynamic information associated with a PMC (i.e., whether enabled,
owner pid, reload count etc.).
Allow pmc_read() (i.e., OPS PMCRW) on active self-attached PMCs to
get upto-date values from hardware since we can guarantee that the
hardware is running the correct PMC at the time of the call.
Bug fixes:
- (x86 class processors) Fix a bug that prevented an RDPMC
instruction from being recognized as permitted till after the
attached process had context switched out and back in again after
a pmc_start() call.
Tighten the rules for using RDPMC class instructions: a GETMSR
OP is now allowed only after an OP ATTACH has been done by the
PMC's owner to itself. OP GETMSR is not allowed for PMCs that
track descendants, for PMCs attached to processes other than
their owner processes.
- (P4/HTT processors only) Fix a bug that caused the MI and MD
layers to get out of sync. Add a new MD operation 'get_config()'
as part of this fix.
- Allow multiple system-mode PMCs at the same row-index but on
different CPUs to be allocated.
- Reject allocation of an administratively disabled PMC.
Misc. code cleanups and refactoring. Improve a few comments.
Only allow a process to use the x86 RDPMC instruction if it has
allocated and attached a PMC to itself.
Inform the MD layer of the "pseudo context switch out" that needs
to be done when the last thread of a process is exiting.
includes the MD header for us. Do not include <machine/specialreg.h>
as it is not a header file that can be included from MI files. It
is included from <machine/pmc_mdep.h> if so needed and possible.
Ok'd: jkoshy@
