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* Fix posix_memalign() for large objects. Now that runs are extents ratherJason Evans2007-03-231-151/+297
| | | | | | | | | | | than binary buddies, the alignment guarantees are weaker, which requires a more complex aligned allocation algorithm, similar to that used for alignment greater than the chunk size. Reported by: matteo Notes: svn path=/head/; revision=167853
* Use extents rather than binary buddies to track free pages withinJason Evans2007-03-231-323/+332
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | chunks. This allows runs to be any multiple of the page size. The primary advantage is that large objects are no longer constrained to be 2^n pages, which can dramatically decrease internal fragmentation for large objects. This also allows the sizes for runs that back small objects to be more finely tuned. Free runs are searched for linearly using the chunk page map (with the help of some heuristic optimizations). This changes the allocation policy from "first best fit" to "first fit". A prototype red-black tree implementation for tracking free runs that implemented "first best fit" did not cause a measurable speed or memory usage difference for realistic chunk sizes (though of course it is possible to construct benchmarks that favor one allocation policy over another). Refine the handling of fullness constraints for small runs to be more tunable. Restructure the per chunk page map to contain only two fields per entry, rather than four. Also, increase each entry from 4 to 8 bytes, since it allows for 32-bit integers, without increasing the number of chunk header pages. Relax the maximum chunk size constraint. This is of no practical interest; it is merely fallout from the chunk page map restructuring. Revamp statistics gathering and reporting to be faster, clearer and more informative. Statistics gathering is fast enough now to have little to no impact on application speed, but it still requires approximately two extra pages of memory per arena (per process). This memory overhead may be acceptable for most systems, but we still need to leave statistics gathering disabled by default in RELENG branches. Rename NO_MALLOC_EXTRAS to MALLOC_PRODUCTION in order to make its intent clearer (i.e. it should be defined in RELENG branches). Notes: svn path=/head/; revision=167828
* Avoid using vsnprintf(3) unless MALLOC_STATS is defined, in order toJason Evans2007-03-201-152/+233
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | avoid substantial potential bloat for static binaries that do not otherwise use any printf(3)-family functions. [1] Rearrange arena_run_t so that the region bitmask can be minimally sized according to constraints related to each bin's size class. Previously, the region bitmask was the same size for all run headers, which wasted a measurable amount of memory. Rather than making runs for small objects as large as possible, make runs as small as possible such that header overhead stays below a certain bound. There are two exceptions that override the header overhead bound: 1) If the bound is impossible to honor, it is relaxed on a per-size-class basis. Since there is one bit of header overhead per object (plus a constant), it is impossible to achieve a header overhead less than or equal to 1/(# of bits per object). For the current setting of maximum 0.5% header overhead, this relaxation comes into play for {2, 4, 8, 16}-byte objects, for which header overhead is (on 64-bit systems) {7.1, 4.3, 2.2, 1.2}%, respectively. 2) There is still a cap on small run size, still set to 64kB. This comes into play for {1024, 2048}-byte objects, for which header overhead is {1.6, 3.1}%, respectively. In practice, this reduces the run sizes, which makes worst case low-water memory usage due to fragmentation less bad. It also reduces worst case high-water run fragmentation due to non-full runs, but this is only a constant improvement (most important to small short-lived processes). Reduce the default chunk size from 2MB to 1MB. Benchmarks indicate that the external fragmentation reduction makes 1MB the new sweet spot (as small as possible without adversely affecting performance). Reported by: [1] kientzle Notes: svn path=/head/; revision=167733
* Modify chunk_alloc() to prefer mmap()ed memory over sbrk()ed memory.Jason Evans2007-02-221-36/+40
| | | | | | | | | | | | | | This has no impact unless USE_BRK is defined (32-bit platforms), in which case user allocations are allocated via mmap() if at all possible, in order to avoid the possibility of unreclaimable chunks in the data segment. Fix an obscure bug in base_alloc() that could have allowed undefined behavior if an application were to use sbrk() in conjunction with a USE_BRK-enabled malloc. Notes: svn path=/head/; revision=166890
* Fix a utrace(2)-related bug in calloc(3).Jason Evans2007-01-311-44/+56
| | | | | | | | | Integrate various pedantic cleanups. Submitted by: Andrew Doran <ad@netbsd.org> Notes: svn path=/head/; revision=166375
* Per Regents of the University of Calfornia letter, remove advertisingWarner Losh2007-01-0958-232/+0
| | | | | | | | | clause. # If I've done so improperly on a file, please let me know. Notes: svn path=/head/; revision=165903
* Implement chunk allocation/deallocation hysteresis by caching one spareJason Evans2006-12-231-51/+86
| | | | | | | | | | | chunk per arena, rather than immediately deallocating all unused chunks. This fixes a potential performance issue when allocating/deallocating an object of size (4kB..1MB] in a loop. Reported by: davidxu Notes: svn path=/head/; revision=165473
* Note that the value from getenv() should not be modified by applications.Tom Rhodes2006-10-121-1/+5
| | | | | | | | PR: 60544 Reviewed by: ru Notes: svn path=/head/; revision=163262
* getenv.3: Put "is" on a line with other wordsTom Rhodes2006-10-071-2/+1
| | | | | | | | | | | getobjformat.3: "takes precedence over" is not an envrionment variable. PR: 75545 Submitted by: n-kogane@syd.odn.ne.jp MFC after: 3 days Notes: svn path=/head/; revision=163108
* Revise markup in recently added manpages.Ruslan Ermilov2006-09-303-43/+48
| | | | Notes: svn path=/head/; revision=162841
* Keep compatible parts in sync with OpenBSD v1.21, add some comments.Andrey A. Chernov2006-09-231-15/+7
| | | | | | | No functional changes. Notes: svn path=/head/; revision=162574
* Remove code #ifndef'ed in prev. commit to stay in sync with OpenBSDAndrey A. Chernov2006-09-221-12/+0
| | | | | | | v1.21 which just do that. Notes: svn path=/head/; revision=162557
* Be more GNU compatible:Andrey A. Chernov2006-09-221-2/+5
| | | | | | | | | don't be greedy on the GNU "::" extension when arg separated by whitespace and POSIX_CORRECTLY is set. From POSIX point of view this is unclear situation, so minimal assumption looks right. Notes: svn path=/head/; revision=162555
* Markup fixes.Ruslan Ermilov2006-09-171-51/+51
| | | | Notes: svn path=/head/; revision=162385
* Change the way base allocation is done for internal malloc dataJason Evans2006-09-081-56/+93
| | | | | | | | | | structures, in order to avoid the possibility of attempted recursive lock acquisition for chunks_mtx. Reported by: Slawa Olhovchenkov <slw@zxy.spb.ru> Notes: svn path=/head/; revision=162163
* alloca() cannot check if the allocation is valid; mention the consequences.Ruslan Ermilov2006-09-051-4/+13
| | | | | | | Obtained from: OpenBSD Notes: svn path=/head/; revision=162040
* Enable TLS on PowerPC.Marcel Moolenaar2006-09-011-1/+0
| | | | Notes: svn path=/head/; revision=161831
* Enable TLS on ia64.Marcel Moolenaar2006-09-011-1/+0
| | | | Notes: svn path=/head/; revision=161803
* Correctly handle the case in calloc(num, size) whereColin Percival2006-08-131-1/+1
| | | | | | | | | | | | | | (size_t)(num * size) == 0 but both num and size are nonzero. Reported by: Ilja van Sprundel Approved by: jasone Security: Integer overflow; calloc was allocating 1 byte in response to a request for a multiple of 2^32 (or 2^64) bytes instead of returning NULL. Notes: svn path=/head/; revision=161263
* Define NO_TLS on PowerPC.Marcel Moolenaar2006-08-091-0/+1
| | | | | | | See also: PR ia64/91846 Notes: svn path=/head/; revision=161131
* Conditionally expand the size_invs lookup table in arena_run_reg_dalloc()Jason Evans2006-07-271-1/+12
| | | | | | | | | | | so that architectures with a quantum of 8 (rather than 16) work. Restore arm's quantum to 8. Submitted by: jmg Notes: svn path=/head/; revision=160761
* Use 4 as QUANTUM_2POW_MIN on arm as it is on any other architecture, to avoidOlivier Houchard2006-07-271-1/+1
| | | | | | | triggering an assertion later. Notes: svn path=/head/; revision=160751
* Fix cpp logic in arena_malloc() to adjust size when assertions are enabled,Jason Evans2006-07-271-23/+19
| | | | | | | | | | | even if stats gathering is disabled. [1] Remove 'size' parameter from several functions that do not use it. Reported by: [1] ache Notes: svn path=/head/; revision=160736
* Use some math tricks in arena_run_reg_dalloc() to avoid actual division, asJason Evans2006-07-011-83/+90
| | | | | | | | | | | | | | | | | | | | well as avoiding a switch statement. This change has no significant impact to performance when branch prediction is successful at predicting the sizes of objects passed to free(), but in the case that the object sizes are semi-random, this change has the potential to prevent many branch prediction misses, thus improving performance substantially. Take advantage of alignment guarantees in ipalloc(), and pad object sizes to something less than a power of two when possible. This has the potential to substantially reduce internal fragmentation for objects allocated via posix_memalign(). Avoid an unnecessary pow2_ceil() call in arena_ralloc(). Submitted by: djam8193ah@hotmail.com Notes: svn path=/head/; revision=160066
* Make the behavior of malloc(0) standards-compliant by getting rid of nil,Jason Evans2006-06-301-48/+46
| | | | | | | | | | | | and instead creating a small allocation for each malloc(0) call. The optional SysV compatibility behavior remains unchanged. Add a couple of assertions. Fix a couple of typos in error message strings. Notes: svn path=/head/; revision=160055
* twalk() expects an `action' function not a comparison function.Giorgos Keramidas2006-06-231-1/+1
| | | | | | | | | | | | The text is correct in the "DESCRIPTION" section, so fix "SYNOPSIS" to use the correct name. PR: docs/90498 Submitted by: Vasil Dimov MFC after: 3 days Notes: svn path=/head/; revision=159879
* Add a missing case for the switch statement in arena_run_reg_dalloc(). [1]Jason Evans2006-06-201-8/+20
| | | | | | | | | | Fix a leak in chunk_dealloc(). [2] Reported by: [1] djam8193ah@hotmail.com, [2] Ville-Pertti Keinonen <will@exomi.com> Notes: svn path=/head/; revision=159798
* o .Xr strtonum(3).Maxim Konovalov2006-05-202-0/+2
| | | | | | | MFC after: 1 week Notes: svn path=/head/; revision=158774
* Correct decoding a string containing '/'.Jung-uk Kim2006-05-191-1/+1
| | | | | | | | PR: 97485 Submitted by: Mikko Tyolajarvi < mbsd at pacbell dot net > Notes: svn path=/head/; revision=158749
* Increase the minimum chunk size by a power of two (32kB --> 64kB, assumingJason Evans2006-05-101-2/+2
| | | | | | | | | | | 4kB pages), in order to avoid dangerous rounding error when calculating fullness limits during run promotion/demotion. Convert a structure bitfield to a normal field in areana_run_t. This should have been changed along with the other fields in revision 1.120. Notes: svn path=/head/; revision=158383
* Change the semantics of brk_max to dynamically deal with data segmentJason Evans2006-04-271-71/+83
| | | | | | | | | | | | | | | | | | bounds. [1] Modify logic for utilizing the data segment, such that it is possible to create huge allocations there. Shrink the data segment when deallocating a chunk, if it is at the end of the data segment. Rename chunk_size to csize in huge_malloc(), in order to avoid masking a static variable of the same name. [1] Reported by: Paul Allen <nospam@ugcs.caltech.edu> Notes: svn path=/head/; revision=158062
* s/soley/solelyJens Schweikhardt2006-04-131-1/+1
| | | | Notes: svn path=/head/; revision=157735
* Add an unreachable return statement, in order to avoid a compiler warningJason Evans2006-04-051-0/+1
| | | | | | | | | for non-standard optimization levels. Reported by: Michael Zach <zach@webges.com> Notes: svn path=/head/; revision=157539
* Only initialize the first per-chunk page map element for free runs. ThisJason Evans2006-04-051-31/+16
| | | | | | | makes run split/coalesce operations of complexity lg(n) rather than n. Notes: svn path=/head/; revision=157532
* Add malloc_usable_size() to the RETURN VALUES section.Jason Evans2006-04-041-1/+6
| | | | Notes: svn path=/head/; revision=157508
* Add init_lock, and use it to protect against allocator initializationJason Evans2006-04-041-8/+21
| | | | | | | | | | | races. This isn't currently necessary for libpthread or libthr, but without it external threads libraries like the linuxthreads port are not safe to use. Reported by: ganbold@micom.mng.net Notes: svn path=/head/; revision=157498
* Refactor per-run bitmap manipulation functions so that bitmap offsets onlyJason Evans2006-04-041-69/+131
| | | | | | | | | | | | | | | | | | | | have to be calculated once per allocator operation. Make nil const. Update various comments. Remove/avoid division where possible. For the one division operation that remains in the critical path, add a switch statement that has a case for each small size class, and do division with a constant divisor in each case. This allows the compiler to generate optimized code that does not use hardware division [1]. Obtained from: peter [1] Notes: svn path=/head/; revision=157463
* Optimize runtime performance, primary using the following techniques:Jason Evans2006-03-301-285/+294
| | | | | | | | | | | | | | | | | | * Avoid choosing an arena until it's certain that an arena is needed for allocation. * Convert division/multiplication to bitshifting where possible. * Avoid accessing TLS variables in single-threaded code. * Reduce the amount of pointer dereferencing. * Move lock acquisition in critical paths to only protect the the code that requires synchronization, and completely remove locking where possible. Notes: svn path=/head/; revision=157310
* Add malloc_usable_size(3).Jason Evans2006-03-284-3/+47
| | | | | | | Discussed with: arch@ Notes: svn path=/head/; revision=157236
* Allow the 'n' option to decrease the number of arenas below the default,Jason Evans2006-03-261-2/+16
| | | | | | | | to as little as one arena. Also, limit the number of arenas to avoid a potential invariant violation in base_alloc(). Notes: svn path=/head/; revision=157162
* Add comments and reformat/rearrange code. There are no significantJason Evans2006-03-261-208/+224
| | | | | | | functional changes in this commit. Notes: svn path=/head/; revision=157161
* Convert TINY_MIN_2POW from a cpp macro to tiny_min_2pow (a variable), andJason Evans2006-03-241-21/+37
| | | | | | | | | | | | | | | | | | determine its value at run time according to other relevant values. This avoids the creation of runs that are incompletely utilized, as long as pagesize isn't too large (>32kB, given the current RUN_MIN_REGS_2POW setting). Increase the size of several structure bitfields in arena_run_t in order to avoid integer overflow in the case that a run's header does not overlap with the space that is usable as application allocation regions. Given the tiny_min_2pow change, this fix has no additional impact unless pagesize is >32kB. Reported by: kris Notes: svn path=/head/; revision=157106
* Add USE_BRK-specific code in malloc_init_hard() to allow the firstJason Evans2006-03-241-65/+110
| | | | | | | | | | | | | | | | | | | | | | internally used chunk to start at the beginning of the heap, rather than at a chunk-aligned address. This reduces mapped memory somewhat for 32-bit architectures. Add the arena_run_link_t type and use it wherever a run object is only used as a ring 'header'. This saves approximately 40 kB of memory per arena. Remove an obsolete (no longer used) code path from base_alloc(), which supported the internal allocation of objects larger than the chunk size. Enhance chunk_dealloc() to cache chunk addresses for all deallocated chunks. This has no impact for most programs, but has the potential to reduce VM map fragmentation for programs that use huge allocations. Notes: svn path=/head/; revision=157070
* Separate completely full runs from runs that are merely almost full, soJason Evans2006-03-201-61/+71
| | | | | | | | | | that no linear searching is necessary if we resort to allocating from a run that is known to be mostly full. There are pathological edge cases that could have caused severely degraded performance, and this change fixes that. Notes: svn path=/head/; revision=156902
* Optimize realloc() to reallocate in place if the old and new sizes areJason Evans2006-03-191-105/+167
| | | | | | | | | | | | | | close enough to each other that reallocation would allocate a new region of the same size. This improves the performance of repeated incremental reallocations by up to three orders of magnitude. [1] Fix arena_new() to properly constrain run size if a small chunk size was specified during runtime configuration. Suggested by: se [1] Notes: svn path=/head/; revision=156890
* Modify allocation policy, in order to avoid excessive fragmentation forJason Evans2006-03-172-2503/+1070
| | | | | | | | | | | | | | | | | | allocation patterns that involve a relatively even mixture of many different size classes. Reduce the chunk size from 16 MB to 2 MB. Since chunks are now carved up using an address-ordered first best fit policy, VM map fragmentation is much less likely, which makes smaller chunks not as much of a risk. This reduces the virtual memory size of most applications. Remove redzones, since program buffer overruns are no longer as likely to corrupt malloc data structures. Remove the C MALLOC_OPTIONS flag, and add H and S. Notes: svn path=/head/; revision=156800
* Add a non-optional newline after ".Bx".Ruslan Ermilov2006-03-151-1/+2
| | | | Notes: svn path=/head/; revision=156741
* Revert previous changes as we do support the .Ox macro for OpenBSD.Andre Oppermann2006-03-151-2/+4
| | | | | | | Pointed out by: ceri, ru, delphij Notes: svn path=/head/; revision=156739
* POSIXed strtoll() (and ours one too) can set errno to EINVAL, so checkAndrey A. Chernov2006-03-141-1/+1
| | | | | | | | | it first. Approved by: andre Notes: svn path=/head/; revision=156716
* Fix HISTORY and point to OpenBSD.Andre Oppermann2006-03-141-5/+2
| | | | Notes: svn path=/head/; revision=156708
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