riscv/qemu - qemu - Gitea: Git with a cup of tea

Commit Graph

Author	SHA1	Message	Date
Daniel P. Berrange	10817bf09d	coroutine: move into libqemuutil.a library The coroutine files are currently referenced by the block-obj-y variable. The coroutine functionality though is already used by more than just the block code. eg migration code uses coroutine yield. In the future the I/O channel code will also use the coroutine yield functionality. Since the coroutine code is nicely self-contained it can be easily built as part of the libqemuutil.a library, making it widely available. The headers are also moved into include/qemu, instead of the include/block directory, since they are now part of the util codebase, and the impl was never in the block/ directory either. Signed-off-by: Daniel P. Berrange <berrange@redhat.com>	11 years ago
Paolo Bonzini	d1d1b206b0	coroutine-ucontext: use __thread ELF thread local storage is about 10% faster on tests/test-coroutine's perf/cost test. The timing on my machine is 190ns per iteration with pthread TLS, 170 with ELF TLS. Based on a patch by Kevin Wolf and Peter Lieven, but redone to follow the model of coroutine-win32.c (including the important "noinline" attribute!). Platforms without thread-local storage (OpenBSD probably?) will need a new-enough GCC for this to compile, in order to use the same emutls support that Windows already relies on. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Message-id: 1417518350-6167-2-git-send-email-pbonzini@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>	11 years ago
Markus Armbruster	e6f53fd514	Fix warnings suppressors to honor --disable-werror Replace #pragma GCC diagnostic ignored FOO [Troublesome code...] #pragma GCC diagnostic error FOO by #pragma GCC diagnostic push #pragma GCC diagnostic ignored FOO [Troublesome code...] #pragma GCC diagnostic pop Broken in commit `3f4349d`, commit `092bb30`, and commit `c95e308`. Signed-off-by: Markus Armbruster <armbru@redhat.com> Tested-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 1366113066-1340-1-git-send-email-armbru@redhat.com Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>	13 years ago
Peter Maydell	6ab7e5465a	Replace all setjmp()/longjmp() with sigsetjmp()/siglongjmp() The setjmp() function doesn't specify whether signal masks are saved and restored; on Linux they are not, but on BSD (including MacOSX) they are. We want to have consistent behaviour across platforms, so we should always use "don't save/restore signal mask" (this is also generally going to be faster). This also works around a bug in MacOSX where the signal-restoration on longjmp() affects the signal mask for a completely different thread, not just the mask for the thread which did the longjmp. The most visible effect of this was that ctrl-C was ignored on MacOSX because the CPU thread did a longjmp which resulted in its signal mask being applied to every thread, so that all threads had SIGINT and SIGTERM blocked. The POSIX-sanctioned portable way to do a jump without affecting signal masks is to siglongjmp() to a sigjmp_buf which was created by calling sigsetjmp() with a zero savemask parameter, so change all uses of setjmp()/longjmp() accordingly. [Technically POSIX allows sigsetjmp(buf, 0) to save the signal mask; however the following siglongjmp() must not restore the signal mask, so the pair can be effectively considered as "sigjmp/longjmp which don't touch the mask".] For Windows we provide a trivial sigsetjmp/siglongjmp in terms of setjmp/longjmp -- this is OK because no user will ever pass a non-zero savemask. The setjmp() uses in tests/tcg/test-i386.c and tests/tcg/linux-test.c are left untouched because these are self-contained singlethreaded test programs intended to be run under QEMU's Linux emulation, so they have neither the portability nor the multithreading issues to deal with. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <rth@twiddle.net> Tested-by: Stefan Weil <sw@weilnetz.de> Reviewed-by: Laszlo Ersek <lersek@redhat.com> Signed-off-by: Blue Swirl <blauwirbel@gmail.com>	13 years ago
Paolo Bonzini	402397843e	coroutine: move pooling to common code The coroutine pool code is duplicated between the ucontext and sigaltstack backends, and absent from the win32 backend. But the code can be shared easily by moving it to qemu-coroutine.c. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>	13 years ago
Gerd Hoffmann	cc6e3ca93c	gcc: rename CONFIG_PRAGMA_DISABLE_UNUSED_BUT_SET to CONFIG_PRAGMA_DIAGNOSTIC_AVAILABLE Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> Signed-off-by: Blue Swirl <blauwirbel@gmail.com>	13 years ago
Paolo Bonzini	737e150e89	block: move include files to include/block/ Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>	13 years ago
Peter Maydell	06d71fa148	configure: Split valgrind test into pragma test and valgrind.h test Split the configure test that checks for valgrind into two, one part checking whether we have the gcc pragma to disable unused-but-set variables, and the other part checking for the existence of valgrind.h. The first of these has to be compiled with -Werror and the second does not and shouldn't generate any warnings. This (a) allows us to enable "make errors in configure tests be build failures" and (b) enables use of valgrind on systems with a gcc which doesn't know about -Wunused-but-set-varibale, like Debian squeeze. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Blue Swirl <blauwirbel@gmail.com>	14 years ago
Kevin Wolf	3f4349dc8b	coroutine-ucontext: Help valgrind understand coroutines valgrind tends to get confused and report false positives when you switch stacks and don't tell it about it. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>	14 years ago
Paolo Bonzini	1bbbdabd56	coroutine: switch to QSLIST QSLIST can be used for a free list, do it. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>	14 years ago
Avi Kivity	39a7a362e1	coroutine: switch per-thread free pool to a global pool ucontext-based coroutines use a free pool to reduce allocations and deallocations of coroutine objects. The pool is per-thread, presumably to improve locality. However, as coroutines are usually allocated in a vcpu thread and freed in the I/O thread, the pool accounting gets screwed up and we end allocating and freeing a coroutine for every I/O request. This is expensive since large objects are allocated via the kernel, and are not cached by the C runtime. Fix by switching to a global pool. This is safe since we're protected by the global mutex. Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>	15 years ago
Anthony Liguori	7267c0947d	Use glib memory allocation and free functions qemu_malloc/qemu_free no longer exist after this commit. Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>	15 years ago
malc	32b746775d	Unbreak the build on ppc32 Signed-off-by: malc <av1474@comtv.ru>	15 years ago
Kevin Wolf	00dccaf1f8	coroutine: introduce coroutines Asynchronous code is becoming very complex. At the same time synchronous code is growing because it is convenient to write. Sometimes duplicate code paths are even added, one synchronous and the other asynchronous. This patch introduces coroutines which allow code that looks synchronous but is asynchronous under the covers. A coroutine has its own stack and is therefore able to preserve state across blocking operations, which traditionally require callback functions and manual marshalling of parameters. Creating and starting a coroutine is easy: coroutine = qemu_coroutine_create(my_coroutine); qemu_coroutine_enter(coroutine, my_data); The coroutine then executes until it returns or yields: void coroutine_fn my_coroutine(void opaque) { MyData my_data = opaque; /* do some work / qemu_coroutine_yield(); / do some more work */ } Yielding switches control back to the caller of qemu_coroutine_enter(). This is typically used to switch back to the main thread's event loop after issuing an asynchronous I/O request. The request callback will then invoke qemu_coroutine_enter() once more to switch back to the coroutine. Note that if coroutines are used only from threads which hold the global mutex they will never execute concurrently. This makes programming with coroutines easier than with threads. Race conditions cannot occur since only one coroutine may be active at any time. Other coroutines can only run across yield. This coroutines implementation is based on the gtk-vnc implementation written by Anthony Liguori <anthony@codemonkey.ws> but it has been significantly rewritten by Kevin Wolf <kwolf@redhat.com> to use setjmp()/longjmp() instead of the more expensive swapcontext() and by Paolo Bonzini <pbonzini@redhat.com> for Windows Fibers support. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>	15 years ago

1 Commits (9c058332f36bc84db57f3d54566228799c5e9605)