points. For library functions, the pattern is __sleep() <--
_libc_sleep() <-- sleep(). The arrows represent weak aliases. For
system calls, the pattern is _read() <-- _libc_read() <-- read().
changes have made this too expensive. This gains about 1.25% on
worldstone on my SMP machine.
Swap-less machines, for instance PicoBSDs, and machines which experience
page-out trafic, check with top(1), will probably want to reenable this
with:
ln -s H /etc/malloc.conf
Suggested by: alc (&dyson ?)
realloc functions check for recursion within the malloc code itself. In
a thread-safe library, the single spinlock ensures that no two threads
go inside the protected code at the same time. The thread implementation
is responsible for ensuring that the spinlock does in fact protect malloc.
There was a window of opportunity in which this was not the case. I'll fix
that with a commit RSN.
Our spinlock implementation allows a particular thread to obtain a lock
multiple times, but release the lock with a single unlock call. Since
we're detecting recursion, we know the lock is already owned by the
current thread in a previous call and must not be released in the
current call. This is really far too dependent on this particular
spinlock implementation, so I've added commented out calls to
THREAD_UNLOCK in the appropriate places. We can activate this code when
spinlock is taught to count each lock operation.
a malloc. The signal handler creates a thread which requires a malloc...
For now, the only thing to do is to block signals. When we move user
pthreads to use the kernel threads, mutexes will be implemented in kernel
space and then malloc can revert.
Dmitrij Tejblum <dima@tejblum.dnttm.rssi.ru>
Various cleanup from Keith Bostic
Reinstate calloc() as a separate funtion, in its own source/object file.
leave the manpage integrated with malloc.3 and friends. Too many things
were broken in this respect.
PR: 4002
Reviewed by: phk
Submitted by: Dmitrij Tejblum <dima@tejblum.dnttm.rssi.ru>
Submitted by: Keith Bostic <bostic@bostic.com>
Various portability and stylistic cleanups.
Kill MALLOC_STATS & the 'D' option.
Fix the 'V' option.
Major overhaul of the man-page.
You milage should not vary.
Reviewed by: Keith Bostic <bostic@bostic.com>
Submitted by: Keith Bostic <bostic@bostic.com>
Malloc cannot use pthread_mutex_init() to initialize a mutex because
the mutex initialization process does a malloc!
libc_r internals skip the malloc and assign an initializer to a static
structure and point the opaque type (pthread_mutex_t in this case) to
that structure. This is done on the assumption that the mutex will never
be destroyed. This style of initialization is only valid inside libc_r
because the structure that is assigned is opaque to the user.
This fix allows a simple program to get to main() again. 8-)
This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.
Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.
Add progname to warning/error message layout. (joerg)
Remove inline assembler, no speed impact, not need for the obfuscation (bde)
Remove on the fly calculation of parameters, no longer critical.
Make D & U flags valid even if we don't support them.
Don't call imalloc until we're done initializing.
Zap contents on free() if we have "Junk" set. [*]
Various nitpicking.
[*] As a sideeffect of this change, if you are worried about
sensitive data lingering in memory, you can use the 'Junk' option
now to make sure phkmalloc zaps memory when it is returned. add
char * malloc_options = "J";
to your source. Obviously there is a performance impact.
Various neat features added. More documentation in the manpage.
If your machine has very little RAM, I guess that would be < 16M
these days :-(, you may want to try this:
ln -fs 'H<' /etc/malloc.conf
check the manpage.
as done after a quasi-recursive call to free() had modified what we
thought we knew about the last chunk of pages.
This bug manifested itself when I did a "make obj" from src/usr.sbin/lpr,
then make would coredump in the lpd directory.
via mmap() up around the shared library area. Previously the directory
was allocated from space from it's own memory pool. Because of the way it
was being extended on processes with large malloced data segments (ie: inn)
once the page directory was extended for some reason, it was not possible
to lower the heap size any more to return pages to the OS.
(If my understanding is correct, page directory expansion occurs at 4MB,
12MB, 20MB, 28MB, etc.) I was seeing INN allocate a large amount of short
term memory, pushing it over the 28MB mark, and once it's transient demands
hit 28MB, it never freed it's pages and swap space again.)
I've been running this in my libc for about a month...
Also, seperate MALLOC_STATS from EXTRA_SANITY.. I found it useful to call
malloc_dump() from within INN from a ctlinnd command to see where the hell
all the memory was going.. :-) I've left MALLOC_STATS enabled, as it has
no run-time or data storage cost.
Reviewed by: phk
Performance is comparable to gnumalloc if you have sufficient RAM, and
it screams around it if you don't.
Compiled with "EXTRA_SANITY" until further notice.
see malloc.3 for more details.
