path: root/compatfd.h
AgeCommit message (Collapse)AuthorFilesLines
2011-07-23Register Linux dyntick timer as per-thread signalJan Kiszka1-0/+1
Derived from kvm-tool patch http://thread.gmane.org/gmane.comp.emulators.kvm.devel/74309 Ingo Molnar pointed out that sending the timer signal to the whole process, just blocking it everywhere, is suboptimal with an increasing number of threads. QEMU is also using this pattern so far. Linux provides a (non-portable) way to restrict the signal to a single thread: We can use SIGEV_THREAD_ID unless we are forced to emulate signalfd via an additional thread. That case could theoretically be optimized as well, but it doesn't look worth bothering. Reviewed-by: Richard Henderson <rth@twiddle.net> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2010-10-20signalfd compatibilityMarcelo Tosatti1-0/+43
Port qemu-kvm's signalfd compat code. commit 5a7fdd0abd7cd24dac205317a4195446ab8748b5 Author: Anthony Liguori <aliguori@us.ibm.com> Date: Wed May 7 11:55:47 2008 -0500 Use signalfd() in io-thread This patch reworks the IO thread to use signalfd() instead of sigtimedwait() This will eliminate the need to use SIGIO everywhere. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2008-10-08Fix IO performance regression in sparcaliguori1-28/+0
Replace signalfd with signal handler/pipe. There is no way to interrupt the CPU execution loop when a file descriptor becomes readable. This results in a large performance regression in sparc emulation during bootup. This patch switches us to signal handler/pipe which was originally suggested by Ian Jackson. The signal handler lets us interrupt the CPU emulation loop while the write to a pipe lets us avoid the select/signal race condition. Signed-off-by: Anthony Liguori <aliguori@us.ibm.com> git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5451 c046a42c-6fe2-441c-8c8c-71466251a162
2008-09-11Fix the build on non-Linux systemsaliguori1-5/+1
It turns out, we're never reading from the signalfd() which is causing it to remain readable forever. I'll fix this up but I thought I'd commit this fix in the interim. Signed-off-by: Anthony Liguori <aliguori@us.ibm.com> git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5194 c046a42c-6fe2-441c-8c8c-71466251a162
2008-09-10Add missing files from previous commit.aliguori1-0/+32
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5188 c046a42c-6fe2-441c-8c8c-71466251a162