On Tue, Apr 21, 2015 at 7:25 AM, Bruce Richardson <
bruce.richardson at intel.com> wrote:
> On Sat, Apr 18, 2015 at 12:43:06PM -0700, Ravi Kerur wrote:
> > Changes in v6
> > Remove RTE_EXEC_ENV_BSDAPP from eal_common_thread.c file.
> > Add pthread_setname_np/pthread_set_name_np for Linux/FreeBSD
> > respectively. Plan to use _getname_ in RTE_LOG when available.
> > Use existing rte_get_systid() in RTE_LOG to print thread_id.
>
> Hi Ravi
>
> I think the change to add names to the threads might be better in an
> existing
> patch as it is separate from the change of making the code common.
> [The code changes for the names also seems to have issues with it, as
> described in comments below]
>
Hi Bruce,
Thanks for your comments. Linux/FreeBSD has different APIs
pthread_setname_np and pthread_getname_np in Linux
pthread_set_name_np in FreeBSD. FreeBSD has no "_get_name_" counterpart API.
API signatures are different as well. Current plan is to use
"_setname_"/"_set_name_" appropriately and leave out "_getname_" until it
is available in FreeBSD.
Are you suggesting to use separate patch for set/get pthread names?
More inline.
> >
> > Changes in v5
> > Rebase to latest code.
> >
> > Changes in v4
> > None
> >
> > Changes in v3
> > Changed subject to be more explicit on file name inclusion.
> >
> > Changes in v2
> > None
> >
> > Changes in v1
> > eal_thread.c has minor differences between Linux and BSD, move
> > entire file into common directory.
> > Use RTE_EXEC_ENV_BSDAPP to differentiate on minor differences.
> > Rename eal_thread.c to eal_common_thread.c
> > Makefile changes to reflect file move and name change.
> > Fix checkpatch warnings.
> >
> > Signed-off-by: Ravi Kerur <rkerur at gmail.com>
> > ---
> > examples/vhost/main.c | 18 ++-
> > examples/vhost_xen/main.c | 18 ++-
> > lib/librte_eal/bsdapp/eal/Makefile | 2 +-
> > lib/librte_eal/bsdapp/eal/eal.c | 7 +
> > lib/librte_eal/bsdapp/eal/eal_thread.c | 152
> ---------------------
> > lib/librte_eal/common/eal_common_thread.c | 147
> +++++++++++++++++++-
> > lib/librte_eal/common/eal_thread.h | 5 +
> > lib/librte_eal/linuxapp/eal/Makefile | 2 +
> > lib/librte_eal/linuxapp/eal/eal.c | 10 ++
> > lib/librte_eal/linuxapp/eal/eal_interrupts.c | 11 ++
> > lib/librte_eal/linuxapp/eal/eal_pci_vfio_mp_sync.c | 22 ++-
> > lib/librte_eal/linuxapp/eal/eal_thread.c | 152
> +--------------------
> > lib/librte_eal/linuxapp/eal/eal_timer.c | 15 +-
> > 13 files changed, 250 insertions(+), 311 deletions(-)
> >
>
> <<<snip>>>
>
> > --- a/lib/librte_eal/linuxapp/eal/eal_pci_vfio_mp_sync.c
> > +++ b/lib/librte_eal/linuxapp/eal/eal_pci_vfio_mp_sync.c
> > @@ -34,6 +34,7 @@
> > #include <string.h>
> > #include <fcntl.h>
> > #include <sys/socket.h>
> > +#include <pthread.h>
> >
> > /* sys/un.h with __USE_MISC uses strlen, which is unsafe */
> > #ifdef __USE_MISC
> > @@ -54,6 +55,7 @@
> >
> > #include "eal_filesystem.h"
> > #include "eal_pci_init.h"
> > +#include "eal_thread.h"
> >
> > /**
> > * @file
> > @@ -374,20 +376,36 @@ int
> > pci_vfio_mp_sync_setup(void)
> > {
> > int ret;
> > + char thread_name[RTE_THREAD_NAME_LEN];
> >
> > if (vfio_mp_sync_socket_setup() < 0) {
> > RTE_LOG(ERR, EAL, "Failed to set up local socket!\n");
> > return -1;
> > }
> >
> > + snprintf(thread_name, RTE_THREAD_NAME_LEN,
> > + "pci-vfio-mp-sync");
>
> This string is too long. According to the man page (Fedora Linux):
> "The thread name is a meaningful C language string, whose length is
> restricted to 16 charac?
> ters, including the terminating null byte ('\0')."
> I make the string 16+ null, i.e. 17 in total.
>
My mistake, will fix it.
>
> > +
> > ret = pthread_create(&socket_thread, NULL,
> > pci_vfio_mp_sync_thread, NULL);
> > if (ret) {
> > - RTE_LOG(ERR, EAL, "Failed to create thread for
> communication with "
> > - "secondary processes!\n");
> > + RTE_LOG(ERR, EAL,
> > + "Failed to create thread for communication with "
> > + "secondary processes!\n");
>
> Should not split the error message string across multiple lines as it
> breaks
> git grep searches for the error message.
>
Will fix it.
>
> > + close(mp_socket_fd);
> > + return -1;
> > + }
> > +
> > + ret = pthread_setname_np(socket_thread, thread_name);
> > +
> > + if (ret) {
> > + RTE_LOG(ERR, EAL,
> > + "Failed to set thread name for "
> > + "secondary processes!\n");
> > close(mp_socket_fd);
> > return -1;
>
> Do we really want to return with an error here. Right now I can't run any
> apps
> since I get an error on init of PCI - due to the name string being too
> long for
> Linux. (Things seem fine on BSD). Failing to name a thread doesn't seem to
> be
> a fatal error IMHO.
>
>
When I coded understanding was that pthread _set_ APIs should not fail
(excluding bugs whilst calling the API), since _get_ APIs will be called
subsequently for logging and debugging it will not be of any help if I let
program continue after _set_ failure. I will change the code to just log an
error and return success.
Thanks,
Ravi
> Regards,
> /Bruce
>
>
