| Message ID | 20240209070141.421569-4-npiggin@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Multi-migration support | expand |
On 09/02/2024 08.01, Nicholas Piggin wrote: > Starting a pipeline of jobs in the background does not seem to have > a simple way to reliably find the pid of a particular process in the > pipeline (because not all processes are started when the shell > continues to execute). > > The way PID of QEMU is derived can result in a failure waiting on a > PID that is not running. This is easier to hit with subsequent > multiple-migration support. Changing this to use $! by swapping the > pipeline for a fifo is more robust. > > Signed-off-by: Nicholas Piggin <npiggin@gmail.com> > --- > scripts/arch-run.bash | 15 +++++++++++---- > 1 file changed, 11 insertions(+), 4 deletions(-) > > diff --git a/scripts/arch-run.bash b/scripts/arch-run.bash > index 1e903e83..3689d7c2 100644 > --- a/scripts/arch-run.bash > +++ b/scripts/arch-run.bash > @@ -130,19 +130,22 @@ run_migration () > fi > > trap 'trap - TERM ; kill 0 ; exit 2' INT TERM > - trap 'rm -f ${migout1} ${migsock} ${qmp1} ${qmp2} ${fifo}' RETURN EXIT > + trap 'rm -f ${migout1} ${migout_fifo1} ${migsock} ${qmp1} ${qmp2} ${fifo}' RETURN EXIT > > migsock=$(mktemp -u -t mig-helper-socket.XXXXXXXXXX) > migout1=$(mktemp -t mig-helper-stdout1.XXXXXXXXXX) > + migout_fifo1=$(mktemp -u -t mig-helper-fifo-stdout1.XXXXXXXXXX) > qmp1=$(mktemp -u -t mig-helper-qmp1.XXXXXXXXXX) > qmp2=$(mktemp -u -t mig-helper-qmp2.XXXXXXXXXX) > fifo=$(mktemp -u -t mig-helper-fifo.XXXXXXXXXX) > qmpout1=/dev/null > qmpout2=/dev/null > > + mkfifo ${migout_fifo1} > eval "$@" -chardev socket,id=mon1,path=${qmp1},server=on,wait=off \ > - -mon chardev=mon1,mode=control | tee ${migout1} & > - live_pid=`jobs -l %+ | grep "eval" | awk '{print$2}'` > + -mon chardev=mon1,mode=control > ${migout_fifo1} & > + live_pid=$! > + cat ${migout_fifo1} | tee ${migout1} & > > # We have to use cat to open the named FIFO, because named FIFO's, unlike > # pipes, will block on open() until the other end is also opened, and that > @@ -150,7 +153,7 @@ run_migration () > mkfifo ${fifo} > eval "$@" -chardev socket,id=mon2,path=${qmp2},server=on,wait=off \ > -mon chardev=mon2,mode=control -incoming unix:${migsock} < <(cat ${fifo}) & > - incoming_pid=`jobs -l %+ | awk '{print$2}'` > + incoming_pid=$! > > # The test must prompt the user to migrate, so wait for the "migrate" keyword > while ! grep -q -i "Now migrate the VM" < ${migout1} ; do > @@ -164,6 +167,10 @@ run_migration () > sleep 1 > done > > + # Wait until the destination has created the incoming and qmp sockets > + while ! [ -S ${migsock} ] ; do sleep 0.1 ; done > + while ! [ -S ${qmp2} ] ; do sleep 0.1 ; done > + > qmp ${qmp1} '"migrate", "arguments": { "uri": "unix:'${migsock}'" }' > ${qmpout1} > > # Wait for the migration to complete Reviewed-by: Thomas Huth <thuth@redhat.com>
diff --git a/scripts/arch-run.bash b/scripts/arch-run.bash index 1e903e83..3689d7c2 100644 --- a/scripts/arch-run.bash +++ b/scripts/arch-run.bash @@ -130,19 +130,22 @@ run_migration () fi trap 'trap - TERM ; kill 0 ; exit 2' INT TERM - trap 'rm -f ${migout1} ${migsock} ${qmp1} ${qmp2} ${fifo}' RETURN EXIT + trap 'rm -f ${migout1} ${migout_fifo1} ${migsock} ${qmp1} ${qmp2} ${fifo}' RETURN EXIT migsock=$(mktemp -u -t mig-helper-socket.XXXXXXXXXX) migout1=$(mktemp -t mig-helper-stdout1.XXXXXXXXXX) + migout_fifo1=$(mktemp -u -t mig-helper-fifo-stdout1.XXXXXXXXXX) qmp1=$(mktemp -u -t mig-helper-qmp1.XXXXXXXXXX) qmp2=$(mktemp -u -t mig-helper-qmp2.XXXXXXXXXX) fifo=$(mktemp -u -t mig-helper-fifo.XXXXXXXXXX) qmpout1=/dev/null qmpout2=/dev/null + mkfifo ${migout_fifo1} eval "$@" -chardev socket,id=mon1,path=${qmp1},server=on,wait=off \ - -mon chardev=mon1,mode=control | tee ${migout1} & - live_pid=`jobs -l %+ | grep "eval" | awk '{print$2}'` + -mon chardev=mon1,mode=control > ${migout_fifo1} & + live_pid=$! + cat ${migout_fifo1} | tee ${migout1} & # We have to use cat to open the named FIFO, because named FIFO's, unlike # pipes, will block on open() until the other end is also opened, and that @@ -150,7 +153,7 @@ run_migration () mkfifo ${fifo} eval "$@" -chardev socket,id=mon2,path=${qmp2},server=on,wait=off \ -mon chardev=mon2,mode=control -incoming unix:${migsock} < <(cat ${fifo}) & - incoming_pid=`jobs -l %+ | awk '{print$2}'` + incoming_pid=$! # The test must prompt the user to migrate, so wait for the "migrate" keyword while ! grep -q -i "Now migrate the VM" < ${migout1} ; do @@ -164,6 +167,10 @@ run_migration () sleep 1 done + # Wait until the destination has created the incoming and qmp sockets + while ! [ -S ${migsock} ] ; do sleep 0.1 ; done + while ! [ -S ${qmp2} ] ; do sleep 0.1 ; done + qmp ${qmp1} '"migrate", "arguments": { "uri": "unix:'${migsock}'" }' > ${qmpout1} # Wait for the migration to complete
Starting a pipeline of jobs in the background does not seem to have a simple way to reliably find the pid of a particular process in the pipeline (because not all processes are started when the shell continues to execute). The way PID of QEMU is derived can result in a failure waiting on a PID that is not running. This is easier to hit with subsequent multiple-migration support. Changing this to use $! by swapping the pipeline for a fifo is more robust. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> --- scripts/arch-run.bash | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-)