qemu/stubs/iothread-lock.c

#include "qemu/osdep.h"
#include "qemu/main-loop.h"

bool qemu_mutex_iothread_locked(void)
{
    return true;
}

void qemu_mutex_lock_iothread_impl(const char *file, int line)
{
}

void qemu_mutex_unlock_iothread(void)
{
}
stubs: Clean up includes Clean up includes so that osdep.h is included first and headers which it implies are not included manually. This commit was created with scripts/clean-includes. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Message-id: 1454089805-5470-3-git-send-email-peter.maydell@linaro.org 2016-01-29 20:49:52 +03:00			`#include "qemu/osdep.h"`
stubs: fully replace qemu-tool.c and qemu-user.c Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> 2012-11-26 18:36:40 +04:00			`#include "qemu/main-loop.h"`

main-loop: introduce qemu_mutex_iothread_locked This function will be used to avoid recursive locking of the iothread lock whenever address_space_rw/ld/st are called with the BQL held, which is almost always the case. Tracking whether the iothread is owned is very cheap (just use a TLS variable) but requires some care because now the lock must always be taken with qemu_mutex_lock_iothread(). Previously this wasn't the case. Outside TCG mode this is not a problem. In TCG mode, we need to be careful and avoid the "prod out of compiled code" step if already in a VCPU thread. This is easily done with a check on current_cpu, i.e. qemu_in_vcpu_thread(). Hopefully, multithreaded TCG will get rid of the whole logic to kick VCPUs whenever an I/O event occurs! Cc: Frederic Konrad <fred.konrad@greensocs.com> Message-Id: <1434646046-27150-3-git-send-email-pbonzini@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> 2015-06-18 19:47:19 +03:00			`bool qemu_mutex_iothread_locked(void)`
			`{`
			`return true;`
			`}`

qsp: track BQL callers explicitly The BQL is acquired via qemu_mutex_lock_iothread(), which makes the profiler assign the associated wait time (i.e. most of BQL wait time) entirely to that function. This loses the original call site information, which does not help diagnose BQL contention. Fix it by tracking the callers explicitly. Signed-off-by: Emilio G. Cota <cota@braap.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> 2017-10-28 09:16:41 +03:00			`void qemu_mutex_lock_iothread_impl(const char *file, int line)`
stubs: fully replace qemu-tool.c and qemu-user.c Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> 2012-11-26 18:36:40 +04:00			`{`
			`}`

			`void qemu_mutex_unlock_iothread(void)`
			`{`
			`}`