On 10/14/2016 5:27 PM, ouster at cs.stanford.edu (John Ousterhout) wrote: > It sounds like my patch would break some existing software, so it probably > doesn't make sense right now. > > I'd still argue that the current mechanism has a number of problems, and it > should probably undergo a comprehensive overhaul at some point in the > future.
Hi John, It seems there weren't any conclusion on the patch and it is sitting on patchwork more than two years, I am updating it as rejected, if it is still relevant please let us know. Sorry for any inconvenience caused. For record, patch: https://patches.dpdk.org/patch/16527/ Regards, ferruh > > -John- > > On Thu, Oct 13, 2016 at 2:39 PM, Tahhan, Maryam <maryam.tahhan at intel.com> > wrote: > >>> Hi John, >>> >>>> Before this patch, DPDK used the file ~/.rte_config as a lock to >>>> detect potential interference between multiple DPDK applications >>>> running on the same machine. However, if a single user ran DPDK >>>> applications concurrently on several different machines, and if the >>>> user's home directory was shared between the machines via NFS, DPDK >>>> would incorrectly detect conflicts for all but the first application >>>> and abort them. This patch fixes the problem by incorporating the >>>> machine name into the config file name (e.g., ~/.rte_hostname_config). >>>> >>>> Signed-off-by: John Ousterhout <ouster at cs.stanford.edu> >>>> --- >>>> doc/guides/prog_guide/multi_proc_support.rst | 11 +++++++---- >>>> lib/librte_eal/common/eal_common_proc.c | 8 ++------ >>>> lib/librte_eal/common/eal_filesystem.h | 15 +++++++++++++-- >>>> 3 files changed, 22 insertions(+), 12 deletions(-) >>>> >>>> diff --git a/doc/guides/prog_guide/multi_proc_support.rst >>>> b/doc/guides/prog_guide/multi_proc_support.rst >>>> index badd102..a54fa1c 100644 >>>> --- a/doc/guides/prog_guide/multi_proc_support.rst >>>> +++ b/doc/guides/prog_guide/multi_proc_support.rst >>>> @@ -129,10 +129,13 @@ Support for this usage scenario is provided >>>> using the ``--file-prefix`` paramete >>>> >>>> By default, the EAL creates hugepage files on each hugetlbfs >>>> filesystem using the rtemap_X filename, where X is in the range 0 to >> the >>> maximum number of hugepages -1. >>>> -Similarly, it creates shared configuration files, memory mapped in >>>> each process, using the /var/run/.rte_config filename, -when run as >>>> root (or $HOME/.rte_config when run as a non-root user; -if filesystem >> and >>> device permissions are set up to allow this). >>>> -The rte part of the filenames of each of the above is configurable >> using the >>> file-prefix parameter. >>>> +Similarly, it creates shared configuration files, memory mapped in >> each >>> process. >>>> +When run as root, the name of the configuration file will be >>>> +/var/run/.rte_*host*_config, where *host* is the name of the machine. >>>> +When run as a non-root user, the the name of the configuration file >>>> +will be $HOME/.rte_*host*_config (if filesystem and device permissions >>> are set up to allow this). >>>> +If the ``--file-prefix`` parameter has been specified, its value will >>>> +be used in place of "rte" in the file names. >>> >>> I am not sure that we need to handle all such cases inside EAL. >>> User can easily overcome that problem by just adding something like: >>> --file-prefix=`uname -n` >>> to his command-line. >>> Konstantin >>> >> >> I agree with Konstantin, there's no need to include the hostname in the >> rte config file + I'm not sure this will be backward compatible with >> existing DPDK applications that use a secondary processes that use the >> config file (as in, multiprocess DPDK applications in use would all need to >> be updated). What Konstantin suggests fixes the issue you were encountering >> without breaking backward compatibility. >> Is addition, the hostname is not unique... you could in theory have 2 >> hosts with the same hostname and encounter the issue you were seeing again. >> >>>> >>>> In addition to specifying the file-prefix parameter, any DPDK >>>> applications that are to be run side-by-side must explicitly limit >> their >>> memory use. >>>> diff --git a/lib/librte_eal/common/eal_common_proc.c >>>> b/lib/librte_eal/common/eal_common_proc.c >>>> index 12e0fca..517aa0c 100644 >>>> --- a/lib/librte_eal/common/eal_common_proc.c >>>> +++ b/lib/librte_eal/common/eal_common_proc.c >>>> @@ -45,12 +45,8 @@ rte_eal_primary_proc_alive(const char >>>> *config_file_path) >>>> >>>> if (config_file_path) >>>> config_fd = open(config_file_path, O_RDONLY); >>>> - else { >>>> - char default_path[PATH_MAX+1]; >>>> - snprintf(default_path, PATH_MAX, RUNTIME_CONFIG_FMT, >>>> - default_config_dir, "rte"); >>>> - config_fd = open(default_path, O_RDONLY); >>>> - } >>>> + else >>>> + config_fd = open(eal_runtime_config_path(), O_RDONLY); >>>> if (config_fd < 0) >>>> return 0; >>>> >>>> diff --git a/lib/librte_eal/common/eal_filesystem.h >>>> b/lib/librte_eal/common/eal_filesystem.h >>>> index fdb4a70..4929aa3 100644 >>>> --- a/lib/librte_eal/common/eal_filesystem.h >>>> +++ b/lib/librte_eal/common/eal_filesystem.h >>>> @@ -41,7 +41,7 @@ >>>> #define EAL_FILESYSTEM_H >>>> >>>> /** Path of rte config file. */ >>>> -#define RUNTIME_CONFIG_FMT "%s/.%s_config" >>>> +#define RUNTIME_CONFIG_FMT "%s/.%s_%s_config" >>>> >>>> #include <stdint.h> >>>> #include <limits.h> >>>> @@ -59,11 +59,22 @@ eal_runtime_config_path(void) >>>> static char buffer[PATH_MAX]; /* static so auto-zeroed */ >>>> const char *directory = default_config_dir; >>>> const char *home_dir = getenv("HOME"); >>>> + static char nameBuffer[1000]; >>>> + int result; >>>> >>>> if (getuid() != 0 && home_dir != NULL) >>>> directory = home_dir; >>>> + >>>> + /* >>>> + * Include the name of the host in the config file path. Otherwise, >>>> + * if DPDK applications run on different hosts but share a home >>>> + * directory (e.g. via NFS), they will choose the same config >>>> + * file and conflict unnecessarily. >>>> + */ >>>> + result = gethostname(nameBuffer, sizeof(nameBuffer)-1); >>>> snprintf(buffer, sizeof(buffer) - 1, RUNTIME_CONFIG_FMT, >>> directory, >>>> - internal_config.hugefile_prefix); >>>> + internal_config.hugefile_prefix, >>>> + (result == 0) ? nameBuffer : "unknown-host"); >>>> return buffer; >>>> } >>>> >>>> -- >>>> 2.8.3 >> >> >
