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* Disable SSE in libthrvangyzen2015-10-261-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Clang emits SSE instructions on amd64 in the common path of pthread_mutex_unlock. If the thread does not otherwise use SSE, this usage incurs a context-switch of the FPU/SSE state, which reduces the performance of multiple real-world applications by a non-trivial amount (3-5% in one application). Instead of this change, I experimented with eagerly switching the FPU state at context-switch time. This did not help. Most of the cost seems to be in the read/write of memory--as kib@ stated--and not in the #NM handling. I tested on machines with and without XSAVEOPT. One counter-argument to this change is that most applications already use SIMD, and the number of applications and amount of SIMD usage are only increasing. This is absolutely true. I agree that--in general and in principle--this change is in the wrong direction. However, there are applications that do not use enough SSE to offset the extra context-switch cost. SSE does not provide a clear benefit in the current libthr code with the current compiler, but it does provide a clear loss in some cases. Therefore, disabling SSE in libthr is a non-loss for most, and a gain for some. I refrained from disabling SSE in libc--as was suggested--because I can't make the above argument for libc. It provides a wide variety of code; each case should be analyzed separately. https://lists.freebsd.org/pipermail/freebsd-current/2015-March/055193.html Suggestions from: dim, jmg, rpaulo Sponsored by: Dell Inc.
* The TCB_GET32() and TCB_GET64() macros in the i386 and amd64-specificdim2011-12-151-1/+1
| | | | | | | | | | | | | | | | | | | | | | versions of pthread_md.h have a special case of dereferencing a null pointer. Clang warns about this with: In file included from lib/libthr/arch/i386/i386/pthread_md.c:36: lib/libthr/arch/i386/include/pthread_md.h:96:10: error: indirection of non-volatile null pointer will be deleted, not trap [-Werror,-Wnull-dereference] return (TCB_GET32(tcb_self)); ^~~~~~~~~~~~~~~~~~~ lib/libthr/arch/i386/include/pthread_md.h:73:13: note: expanded from: : "m" (*(u_int *)(__tcb_offset(name)))); \ ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ lib/libthr/arch/i386/include/pthread_md.h:96:10: note: consider using __builtin_trap() or qualifying pointer with 'volatile' Since this indirection is done relative to the fs or gs segment, to retrieve thread-specific data, it is an exception to the rule. Therefore, add a volatile qualifier to tell the compiler we really want to dereference a zero address. MFC after: 1 week
* Add section .note.GNU-stack for assembly files used by 386 and amd64.kib2011-01-071-0/+2
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* Merge from tbemd, with a small amount of rework:imp2010-09-131-2/+0
| | | | | | | | | | For all libthr contexts, use ${MACHINE_CPUARCH} for all libc contexts, use ${MACHINE_ARCH} if it exists, otherwise use ${MACHINE_CPUARCH} Move some common code up a layer (the .PATH statement was the same in all the arch submakefiles). # Hope she hasn't busted powerpc64 with this...
* Replace function _umtx_op with _umtx_op_err, the later function directlydavidxu2008-04-023-1/+40
| | | | | | returns errno, because errno can be mucked by user's signal handler and most of pthread api heavily depends on errno to be correct, this change should improve stability of the thread library.
* style.Makefile(5)obrien2008-02-131-1/+1
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* - Remove variable _thr_scope_system, all threads are system scope.davidxu2006-12-151-0/+2
| | | | | - Rename _thr_smp_cpus to boolean variable _thr_is_smp. - Define CPU_SPINWAIT macro for each arch, only X86 supports it.
* Remove declaration of _thr_initial from MD header file, it is no longerdavidxu2006-04-041-2/+0
| | | | needed.
* Simplify _get_curthread() and _tcb_ctor because libc and rtld nowdavidxu2006-04-042-8/+3
| | | | | already allocate thread pointer space in tls block for initial thread. Only i386 and amd64 have been done, others still have to be tested.
* Remove functions i386_get_gsbase and i386_set_gsbase, they were alreadydavidxu2006-01-071-14/+0
| | | | in libc.
* Kill unused variable declaration.davidxu2005-10-291-2/+0
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* Remove COMPAT_32BIT, it is no longer needed.davidxu2005-04-271-5/+0
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* Remove unused variable.davidxu2005-04-231-1/+0
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* Now libthr only uses GDT based tls on i386. using LDT can only increasedavidxu2005-04-232-53/+3
| | | | clock cycles and has 8191 threads limitation.
* Add i386_get_gsbase, i386_set_gsbase since old libc doesn't have thedavidxu2005-04-231-0/+14
| | | | functions, otherwise user ports have to be rebuilt.
* Adapt the libpthread patch for using i386_set_gsbase() to libthr.peter2005-04-142-16/+41
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* Import my recent 1:1 threading working. some features improved includes:davidxu2005-04-025-155/+202
| | | | | | | | | | | | | | | | 1. fast simple type mutex. 2. __thread tls works. 3. asynchronous cancellation works ( using signal ). 4. thread synchronization is fully based on umtx, mainly, condition variable and other synchronization objects were rewritten by using umtx directly. those objects can be shared between processes via shared memory, it has to change ABI which does not happen yet. 5. default stack size is increased to 1M on 32 bits platform, 2M for 64 bits platform. As the result, some mysql super-smack benchmarks show performance is improved massivly. Okayed by: jeff, mtm, rwatson, scottl
* Fix inverted #ifdef that I added. Who had the pointy hat last?peter2004-12-061-1/+1
| | | | Submitted by: kan
* Use the recently exposed fs/gs set functions when compiling libthr topeter2004-11-061-0/+12
| | | | | | | run as a 32 bit support library for an amd64 kernel. 32 bit consumers of libthr have zero chance of running on an amd64 kernel since we don't implement the i386_set_ldt() family of functions. Note that this commit doesn't make it actually work, it just removes one more obstacle.
* Adjust code to support AMD64, on AMD64, thread needs to set fsbase bydavidxu2004-08-191-3/+10
| | | | | itself before it can execute any other code, so new thread should be created with all signals are masked until after fsbase is set.
* Add TLS support for libthr on i386.dfr2004-08-152-74/+29
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* Make NULL a (void*)0 whereever possible, and fix the warnings(-Werror)markm2004-03-051-1/+1
| | | | | | | | | | | | | | | that this provokes. "Wherever possible" means "In the kernel OR NOT C++" (implying C). There are places where (void *) pointers are not valid, such as for function pointers, but in the special case of (void *)0, agreement settles on it being OK. Most of the fixes were NULL where an integer zero was needed; many of the fixes were NULL where ascii <nul> ('\0') was needed, and a few were just "other". Tested on: i386 sparc64
* Bump up the maximum number concurrent threads on x86.mtm2004-02-011-1/+1
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* Use dynamic instead of static LDT allocation.mtm2003-12-021-5/+4
| | | | Approved by: re (scottl)
* The move to _retire() a thread in the GC instead of in the thread'smtm2003-06-291-4/+2
| | | | | | | exit function has invalidated the need for _spin[un]lock_pthread(). The _spin[un]lock() functions can now dereference curthread without the danger that the ldtentry containing the pointer to the thread has been cleared out from under them.
* .S comments must be C comments, not ASM ones.obrien2003-06-021-1/+1
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* Missing unlock.mtm2003-05-291-0/+2
| | | | Approved by: re/jhb
* Return gracefully, rather than aborting, when the maximum concurrentmtm2003-05-251-3/+8
| | | | | | threads per process has been reached. Return EAGAIN, as per spec. Approved by: re/blanket libthr
* Add two functions: _spinlock_pthread() and _spinunlock_pthread()mtm2003-05-231-2/+4
| | | | | | | | | | that take the address of a struct pthread as their first argument. _spin[un]lock() just become wrappers arround these two functions. These new functions are for use in situations where curthread can't be used. One example is _thread_retire(), where we invalidate the array index curthread uses to get its pointer.. Approved by: re/blanket libthr
* Make WARNS2 clean. The fixes mostly included:mtm2003-05-231-0/+5
| | | | | | | | o removed unused variables o explicit inclusion of header files o prototypes for externally defined functions Approved by: re/blanket libthr
* o Make the defenition of _set_curthread() match its declarationmtm2003-05-211-5/+27
| | | | | | | | | | | | in thr_private.h o Lock down the ldt_entries array and ldt_free, which points to the next free slot. As noted in the comments, it's necessary to special case the initial_thread because %gs is not setup for it yet. This is ok because that early in the program there won't be any reentrancy issues anyways. Approved by: re/blanket libthr
* Fix a null dereference leading to a core dump whenmtm2003-05-061-1/+4
| | | | | | | | the number of threads exceeds the number of open slots in ldt_entries[]. Approved by: markm (mentor)(implicit) Reviewed by: jeff
* - Pass a ucontext_t to _set_curthread. If non-NULL the new thread is setjake2003-04-031-2/+6
| | | | | | | | as curthread in the new context, so that it will be set automatically when the thread is switched to. This fixes a race where we'd run for a little while with curthread unset in _thread_start. Reviewed by: jeff
* - Don't overrun the ldt buffer.jeff2003-04-021-2/+2
| | | | Submitted by: gordan@freebsd.org
* - Adjust the makefiles so we have a per architecture makefile.jeff2003-04-011-0/+5
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* - Add libthr but don't hook it up to the regular build yet. This is anjeff2003-04-012-0/+139
adaptation of libc_r for the thr system call interface. This is beta quality code.
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