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* Restructure and use different variables in the tests that involvescf2008-08-031-13/+15
| | | | | | | | | environ[0] to be more obvious that environ is not NULL before environ[0] is tested. Although I believe the previous code worked, this change improves code maintainability. Reviewed by: ache MFC after: 3 days
* Detect if the application has cleared the environ variable by settingscf2008-08-021-7/+12
| | | | | | | | | | | | | | | | | | | | | | | | the first value (environ[0]) to NULL. This is in addition to the current detection of environ being replaced, which includes being set to NULL. Without this fix, the environment is not truly wiped, but appears to be by getenv() until an *env() call is made to alter the enviroment. This change is necessary to support those applications that use this method for clearing environ such as Dovecot and Postfix. Applications such as Sendmail and the base system's env replace environ (already detected). While neither of these methods are defined by SUSv3, it is best to support them due to historic reasons and in lieu of a clean, defined method. Add extra units tests for clearing environ using four different methods: 1. Set environ to NULL pointer. 2. Set environ[0] to NULL pointer. 3. Set environ to calloc()'d NULL-terminated array. 4. Set environ to static NULL-terminated array. Noticed by: Timo Sirainen MFC after: 3 days
* Enhance arena_chunk_map_t to directly support run coalescing, and usejasone2008-07-181-394/+338
| | | | | | | the chunk map instead of red-black trees where possible. Remove the red-black trees and node objects that are obsoleted by this change. The net result is a ~1-2% memory savings, and a substantial allocation speed improvement.
* - This code was intially obtained from NetBSD, but it's missing licencedanger2008-07-061-1/+29
| | | | | | | | | statement. Add the one from the current NetBSD version. - Also bump a date to reflect my content changes I have done in previous revision Approved by: imp MFC after: 3 days
* - Add description about a missing return valuedanger2008-07-061-2/+6
| | | | | | PR: docs/75995 Submitted by: Tarc <tarc@po.cs.msu.su> MFC after: 3 days
* - remove superfluous worddanger2008-07-061-3/+3
| | | | | | - remove contractions MFC after: 3 days
* Mark the section describing return values with an appropriate section flag.danger2008-06-261-1/+1
| | | | | PR: docs/122818 MFC after: 3 days
* Don't export the unused __use_pts() routine.ed2008-06-172-2/+1
| | | | | | | | | | The __use_pts() routine was once probably used by libutil to determine if we are using BSD or UNIX98 style PTY device names. It doesn't seem to be used outside grantpt.c, which means we can make it static and remove it from the Symbol.map. Reviewed by: cognet, kib Approved by: philip (mentor)
* In the error path through base_alloc(), release base_mtx [1].jasone2008-06-101-3/+7
| | | | | | Fix bit vector initialization for run headers. Submitted by: [1] Mike Schuster <schuster@adobe.com>
* Clean up cpp logic and comments.jasone2008-05-141-8/+21
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* Fix a comment.jasone2008-05-031-1/+1
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* Add a separate tree to track arena chunks that contain dirty pages.jasone2008-05-011-157/+133
| | | | | | | This substantially improves worst case allocation performance, since O(lg n) tree search can be used instead of O(n) tree iteration. Use rb_wrap() instead of directly calling rb_*() macros.
* Add rb_wrap(), which creates C function wrappers for most rb_*()jasone2008-05-011-36/+194
| | | | | | | | | | macros. Add rb_foreach_next() and rb_foreach_reverse_prev(), which make it possible to re-synchronize tree iteration after the tree has been modified. Rename rb_tree_new() to rb_new().
* Set QUANTUM_2POW_MIN and SIZEOF_PTR_2POW parameters for MIPSgonzo2008-04-291-0/+5
| | | | Approved by: imp
* Check for integer overflow before calling sbrk(2), since it uses ajasone2008-04-291-0/+7
| | | | signed increment argument, but the size is an unsigned integer.
* Stricter check for integer overflow.ru2008-04-241-0/+2
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* Implement red-black trees without using parent pointers, and store thejasone2008-04-232-116/+947
| | | | | | | | | color bit in the least significant bit of the right child pointer, in order to reduce red-black tree linkage overhead by ~2X as compared to sys/tree.h. Use the new red-black tree implementation in malloc, which drops memory usage by ~0.5 or ~1%, for 32- and 64-bit systems, respectively.
* Don't forget to free() currency_symbol and asciivalue when multipleru2008-04-191-0/+4
| | | | | | | | conversion specifiers for them are present. Submitted by: Maxim Dounin <mdounin@mdounin.ru> Obtained from: NetBSD (partially) MFC after: 3 days
* Better strfmon(3) conversion specifiers sanity checking.ru2008-04-191-1/+8
| | | | | | | | | | There were no checks for left and right precisions at all, and a check for field width had integer overflow bug. Reported by: Maksymilian Arciemowicz Security: http://securityreason.com/achievement_securityalert/53 Submitted by: Maxim Dounin <mdounin@mdounin.ru> MFC after: 3 days
* Use calloc() instaed of zeroing memory ourselves.delphij2008-04-131-2/+1
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* Remove stale #include <machine/atomic.h>, which as needed by lazyjasone2008-03-071-4/+4
| | | | deallocation.
* Replace the use of warnx() with direct output to stderr using _write().scf2008-02-281-12/+36
| | | | | | | | | | | | | | | | This reduces the size of a statically-linked binary by approximately 100KB in a trivial "return (0)" test application. readelf -S was used to verify that the .text section was reduced and that using strlen() saved a few more bytes over using sizeof(). Since the section of code is only called when environ is corrupt (program bug), I went with fewer bytes over fewer cycles. I made minor edits to the submitted patch to make the output resemble warnx(). Submitted by: kib bz Approved by: wes (mentor) MFC after: 5 days
* Fix a race condition in arena_ralloc() for shrinking in-place largejasone2008-02-171-25/+41
| | | | | | | | reallocation, when junk filling is enabled. Junk filling must occur prior to shrinking, since any deallocated trailing pages are immediately available for use by other threads. Reported by: Mats Palmgren <mats.palmgren@bredband.net>
* Remove support for lazy deallocation. Benchmarks across a wide range ofjasone2008-02-172-221/+4
| | | | | | | | allocation patterns, number of CPUs, and MALLOC_OPTIONS settings indicate that lazy deallocation has the potential to worsen throughput dramatically. Performance degradation occurs when multiple threads try to clear the lazy free cache simultaneously. Various experiments to avoid this bottleneck failed to completely solve this problem, while adding yet more complexity.
* Fix a bug in lazy deallocation that was introduced whenjasone2008-02-081-7/+10
| | | | | | | | arena_dalloc_lazy_hard() was split out of arena_dalloc_lazy() in revision 1.162. Reduce thundering herd problems in lazy deallocation by randomly varying how many probes a thread does before taking the slow path.
* Clean up manipulation of chunk page map elements to remove some tenuousjasone2008-02-081-362/+357
| | | | | | | | | | | assumptions about whether bits are set at various times. This makes adding other flags safe. Reorganize functions in order to inline i{m,c,p,s,re}alloc(). This allows the entire fast-path call chains for malloc() and free() to be inlined. [1] Suggested by: [1] Stuart Parmenter <stuart@mozilla.com>
* Track dirty unused pages so that they can be purged if they exceed ajasone2008-02-062-679/+973
| | | | | | | | | | | | | | | | | | | | | | | | | threshold, according to the 'F' MALLOC_OPTIONS flag. This obsoletes the 'H' flag. Try to realloc() large objects in place. This substantially speeds up incremental large reallocations in the common case. Fix a bug in arena_ralloc() that caused relocation of sub-page objects even if the old and new sizes were in the same size class. Maintain trees of runs and simplify the per-chunk page map. This allows logarithmic-time searching for sufficiently large runs in arena_run_alloc(), whereas the previous algorithm required linear time in the worst case. Break various large functions into smaller sub-functions, and inline only the functions that are in the fast path for small object allocation/deallocation. Remove an unnecessary check in base_pages_alloc_mmap(). Avoid integer division in choose_arena() for the NO_TLS case on single-CPU systems.
* Remove some now-unused macros.jhb2008-01-151-3/+1
| | | | MFC after: 1 week
* Put back the openpty(3) and ptsname(3) fixes but don't disable ptsname(3)jhb2008-01-151-46/+31
| | | | | on pts(4) devices this time. This fixes the issues while leaving pts(4) enabled on HEAD.
* Back out last commit, since it accidentally broke pts.cperciva2008-01-151-37/+48
| | | | | The security fix will be re-committed soon, hopefully without breaking anything.
* Fix issues which allow snooping on ptys. [08:01]cperciva2008-01-141-48/+37
| | | | | | | Fix an off-by-one error in inet_network(3). [08:02] Security: FreeBSD-SA-08:01.pty Security: FreeBSD-SA-08:02.libc
* Changing 'r' to a size_t in the previous commit turned quicksortdas2008-01-141-4/+5
| | | | | | | into slowsort for some sequences because different parts of the code used 'r' to store two different things, one of which was signed. Clean things up by splitting 'r' into two variables, and use a more meaningful name.
* Use size_t to avoid overflow when sorting arrays larger than 2 GB.das2008-01-132-2/+3
| | | | | PR: 111085 MFC after: 2 weeks
* Enable both sbrk(2)- and mmap(2)-based memory acquisition methods byjasone2008-01-032-19/+20
| | | | | | | | | default. This has the disadvantage of rendering the datasize resource limit irrelevant, but without this change, legitimate uses of more memory than will fit in the data segment are thwarted by default. Fix chunk_alloc_mmap() to work correctly if initial mapping is not chunk-aligned and mapping extension fails.
* Fix a major chunk-related memory leak in chunk_dealloc_dss_record(). [1]jasone2007-12-311-65/+56
| | | | | | | | Clean up DSS-related locking and protect all pertinent variables with dss_mtx (remove dss_chunks_mtx). This fixes race conditions that could cause chunk leaks. Reported by: [1] kris
* Fix a bug related to sbrk() calls that could cause address space leaks.jasone2007-12-311-186/+268
| | | | | | | | | | | | | | | | | | | | | | | | | This is a long-standing bug, but until recent changes it was difficult to trigger, and even then its impact was non-catastrophic, with the exception of revision 1.157. Optimize chunk_alloc_mmap() to avoid the need for unmapping pages in the common case. Thanks go to Kris Kennaway for a patch that inspired this change. Do not maintain a record of previously mmap'ed chunk address ranges. The original intent was to avoid the extra system call overhead in chunk_alloc_mmap(), which is no longer a concern. This also allows some simplifications for the tree of unused DSS chunks. Introduce huge_mtx and dss_chunks_mtx to replace chunks_mtx. There was no compelling reason to use the same mutex for these disjoint purposes. Avoid memset() for huge allocations when possible. Maintain two trees instead of one for tracking unused DSS address ranges. This allows scalable allocation of multi-chunk huge objects in the DSS. Previously, multi-chunk huge allocation requests failed if the DSS could not be extended.
* Back out premature commit of previous version.jasone2007-12-281-183/+113
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* Maintain two trees instead of one (old_chunks --> old_chunks_{ad,szad}) injasone2007-12-281-113/+183
| | | | | | | | | order to support re-use of multi-chunk unused regions within the DSS for huge allocations. This generalization is important to correct function when mmap-based allocation is disabled. Avoid zeroing re-used memory in the DSS unless it really needs to be zeroed.
* Release chunks_mtx for all paths through chunk_dealloc().jasone2007-12-281-1/+4
| | | | Reported by: kris
* Add the 'D' and 'M' run time options, and use them to control whetherjasone2007-12-272-315/+492
| | | | | | | | | | | | | | | | | | memory is acquired from the system via sbrk(2) and/or mmap(2). By default, use sbrk(2) only, in order to support traditional use of resource limits. Additionally, when both options are enabled, prefer the data segment to anonymous mappings, in order to coexist better with large file mappings in applications on 32-bit platforms. This change has the potential to increase memory fragmentation due to the linear nature of the data segment, but from a performance perspective this is mitigated by the use of madvise(2). [1] Add the ability to interpret integer prefixes in MALLOC_OPTIONS processing. For example, MALLOC_OPTIONS=lllllllll can now be specified as MALLOC_OPTIONS=9l. Reported by: [1] rwatson Design review: [1] alc, peter, rwatson
* Clean up some of the pts(4) vs pty(4) stuff in grantpt(3) and friends:jhb2007-12-211-22/+23
| | | | | | | | | | - Use PTY* for all pty(4) related constants. - Use PTMX* for all pts(4) related constants. - Consistently use _PATH_DEV PTMX rather than "/dev/ptmx". - Revert 1.7 and properly fix it by using the correct prefix string for pts(4) masters. MFC after: 3 days
* Use fixed point integer math instead of floating point math whenjasone2007-12-181-42/+47
| | | | | | | | | | calculating run sizes. Use of the floating point unit was a potential pessimization to context switching for applications that do not otherwise use floating point math. [1] Reformat cpp macro-related comments to improve consistency. Submitted by: das
* Refactor features a bit in order to make it possible to disable lazyjasone2007-12-171-52/+127
| | | | | | | | | deallocation and dynamic load balancing via the MALLOC_LAZY_FREE and MALLOC_BALANCE knobs. This is a non-functional change, since these features are still enabled when possible. Clean up a few things that more pedantic compiler settings would cause complaints over.
* Implement and document nan(), nanf(), and nanl(). This commitdas2007-12-161-4/+23
| | | | | | | adds two new directories in msun: ld80 and ld128. These are for long double functions specific to the 80-bit long double format used on x86-derived architectures, and the 128-bit format used on sparc64, respectively.
* Update posix_openpt(3) to handle 512 ptys. This was missed in the earlierjhb2007-12-131-2/+2
| | | | | | pty(4) changes. MFC after: 3 days
* Fix typo in the commentache2007-12-111-1/+1
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* Only zero large allocations when necessary (for calloc()).jasone2007-11-281-1/+1
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* Document the B and L MALLOC_OPTIONS.jasone2007-11-271-1/+26
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* Implement dynamic load balancing of thread-->arena mapping, based on lockjasone2007-11-271-58/+297
| | | | | | | | | | | | | | | | | contention. The intent is to dynamically adjust to load imbalances, which can cause severe contention. Use pthread mutexes where possible instead of libc "spinlocks" (they aren't actually spin locks). Conceptually, this change is meant only to support the dynamic load balancing code by enabling the use of spin locks, but it has the added apparent benefit of substantially improving performance due to reduced context switches when there is moderate arena lock contention. Proper tuning parameter configuration for this change is a finicky business, and it is very much machine-dependent. One seemingly promising solution would be to run a tuning program during operating system installation that computes appropriate settings for load balancing. (The pthreads adaptive spin locks should probably be similarly tuned.)
* Implement lazy deallocation of small objects. For each arena, maintain ajasone2007-11-271-0/+218
| | | | | | | | | | | vector of slots for lazily freed objects. For each deallocation, before doing the hard work of locking the arena and deallocating, try several times to randomly insert the object into the vector using atomic operations. This approach is particularly effective at reducing contention for multi-threaded applications that use the producer-consumer model, wherein one producer thread allocates objects, then multiple consumer threads deallocate those objects.
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