pmc_flush_logfile is now non-blocking and just ask the kernel
to shutdown the file. From that point, no more data is
accepted by the log thread and when the last buffer is flushed
the file is closed.
This will remove a deadlock between pmcstat asking for
flush while it cannot flush the pipe itself.
MFC after: 3 days
- fix a system deadlock on process exit when the sample buffer
is full (pmclog_loop blocked in fo_write) and pmcstat exit.
Reviewed by: jkoshy
MFC after: 3 weeks
for the pmclog.
Reported by: Ryan Stone <rstone at sandvine dot com>
Tested by: Ryan Stone <rstone at sandvine dot com>
Sponsored by: Sandvine Incorporated
and Core Duo), models 0xF (Core2), model 0x17 (Core2Extreme) and
model 0x1C (Atom).
In these CPUs, the actual numbers, kinds and widths of PMCs present
need to queried at run time. Support for specific "architectural"
events also needs to be queried at run time.
Model 0xE CPUs support programmable PMCs, subsequent CPUs
additionally support "fixed-function" counters.
- Use event names that are close to vendor documentation, taking in
account that:
- events with identical semantics on two or more CPUs in this family
can have differing names in vendor documentation,
- identical vendor event names may map to differing events across
CPUs,
- each type of CPU supports a different subset of measurable
events.
Fixed-function and programmable counters both use the same vendor
names for events. The use of a class name prefix ("iaf-" or
"iap-" respectively) permits these to be distinguished.
- In libpmc, refactor pmc_name_of_event() into a public interface
and an internal helper function, for use by log handling code.
- Minor code tweaks: staticize a global, freshen a few comments.
Tested by: gnn
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.
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)
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)
- 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)
- 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.
