Commit Graph

4 Commits

Author SHA1 Message Date
Emilio G. Cota cb764d0665 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>
2018-08-23 18:46:25 +02:00
Peter Maydell 87c9b5e047 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
2016-02-04 17:01:04 +00:00
Paolo Bonzini afbe70535f 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>
2015-07-01 15:45:50 +02:00
Paolo Bonzini 5708fc6655 stubs: fully replace qemu-tool.c and qemu-user.c
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-01-12 17:19:08 +01:00