gwj / at91sam9263 · Commits

Commit 2c41a5f9e355412bdab3d92329ae5637bbdb08f1

Authored by aliguori
1 parent da3d9c5b

Make sure to read siginfo from signalfd 

Otherwise, we'll idle at 100% cpu.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5195 c046a42c-6fe2-441c-8c8c-71466251a162
Inline Side-by-side
Showing 1 changed file with 27 additions and 0 deletions
block-raw-posix.c
  View file @2c41a5f
... ... @@ -449,6 +449,30 @@ static void qemu_aio_poll(void *opaque)
449 449 {
450 450 RawAIOCB *acb, **pacb;
451 451 int ret;
  452 + size_t offset;
  453 + union {
  454 + struct qemu_signalfd_siginfo siginfo;
  455 + char buf[128];
  456 + } sig;
  457 +
  458 + /* try to read from signalfd, don't freak out if we can't read anything */
  459 + offset = 0;
  460 + while (offset < 128) {
  461 + ssize_t len;
  462 +
  463 + len = read(aio_sig_fd, sig.buf + offset, 128 - offset);
  464 + if (len == -1 && errno == EINTR)
  465 + continue;
  466 + if (len == -1 && errno == EAGAIN) {
  467 + /* there is no natural reason for this to happen,
  468 + * so we'll spin hard until we get everything just
  469 + * to be on the safe side. */
  470 + if (offset > 0)
  471 + continue;
  472 + }
  473 +
  474 + offset += len;
  475 + }
452 476  
453 477 for(;;) {
454 478 pacb = &first_aio;
... ... @@ -498,6 +522,9 @@ void qemu_aio_init(void)
498 522 sigprocmask(SIG_BLOCK, &mask, NULL);
499 523  
500 524 aio_sig_fd = qemu_signalfd(&mask);
  525 +
  526 + fcntl(aio_sig_fd, F_SETFL, O_NONBLOCK);
  527 +
501 528 #if !defined(QEMU_IMG) && !defined(QEMU_NBD)
502 529 qemu_set_fd_handler2(aio_sig_fd, NULL, qemu_aio_poll, NULL, NULL);
503 530 #endif
... ...