On Mon, Jul 10, 2017 at 07:05:12PM +0300, Yishai Hadas wrote: > On 7/10/2017 6:58 PM, Leon Romanovsky wrote: > > On Mon, Jul 10, 2017 at 06:05:32PM +0300, Yishai Hadas wrote: > > > This patch set from Maor adds support for device hot plug. > > > Sending V1 to handle some cleanup note came on github from Jason, details > > > below. > > > > > > Hot plug is the method in which a new hardware becomes available in the system > > > or is being removed from it. > > > > > > The IB device list is returned by ibv_get_device_list() from libibverbs. > > > Today, this list is created once by scanning /sys/class/infiniband_verbs, the > > > list is cached and never updated, no matter if there were hardware changes in > > > the system. > > > > > > libibverbs must be able to provide the application access to new ibv_device > > > objects, according to the recent system hardware changes. > > > > > > For this purpose, the device scanning logic, should be separated from the > > > libibverbs singleton initialization step, an updated list should be returned > > > upon any call to ibv_get_device_list(). > > > > > > User can call ibv_open_device() while holding this list (see man pages) and once > > > ibv_free_device_list() is called libibverbs can release the unused ibv_device > > > objects. Later, upon a call to ibv_close_device() the ibv_device object should > > > be released. > > > > > > Currently, on ibv_free_device_list(), only the array is freed, while the > > > ibv_device objects are never freed. > > > > > > This series comes to handle the above notes based on the discussion that followed > > > an RFC on that. > > > > > > The solution: > > > - The initialization part was separated from ibv_get_device_list(). > > > - Upon a call to ibv_get_device_list() the sysfs is scanned to look for > > > new/removed entries. > > > - Same device is recognized based on name and timestamp creation. > > > - libibverbs will maintain a ref count for each verbs_device object, once > > > it became zero, it calls the provider library to release the 'strcut > > > verbs_device' which it allocated before. For this purpose each provider library > > > provide a function to release the verbs_device. > > > > > > Further details exist in the commit logs of the series. > > > > > > Pull request was sent: > > > https://github.com/linux-rdma/rdma-core/pull/157 > > > > > > Changes from V0: > > > #Patch #3: Use the introduced mutex also for the initialization step, dropping > > > the pthread_once usage. > > > > > > Yishai > > > Maor Gottlieb (5): > > > utils: Add timespec compare utility > > > verbs: Split ibverbs_init functionality > > > verbs: Refresh cahced ibv_device list > > > verbs: Avoid ibv_device memory leak > > > providers: Add support for uninit_device for all providers > > > > > > debian/libibverbs1.symbols | 2 +- > > > libibverbs/device.c | 50 +++++++---- > > > libibverbs/driver.h | 6 ++ > > > libibverbs/ibverbs.h | 5 +- > > > libibverbs/init.c | 166 ++++++++++++++++++++++++------------- > > > libibverbs/libibverbs.map | 2 +- > > > providers/cxgb3/iwch.c | 10 ++- > > > providers/cxgb4/dev.c | 10 ++- > > > providers/hfi1verbs/hfiverbs.c | 10 ++- > > > providers/hns/hns_roce_u.c | 10 ++- > > > providers/i40iw/i40iw_umain.c | 10 ++- > > > providers/ipathverbs/ipathverbs.c | 10 ++- > > > providers/mlx4/mlx4.c | 8 ++ > > > providers/mlx5/mlx5.c | 8 ++ > > > providers/mthca/mthca.c | 10 ++- > > > providers/nes/nes_umain.c | 9 +- > > > providers/ocrdma/ocrdma_main.c | 10 ++- > > > providers/qedr/qelr_main.c | 10 ++- > > > providers/rxe/rxe.c | 8 ++ > > > providers/vmw_pvrdma/pvrdma_main.c | 10 ++- > > > srp_daemon/srp_daemon.h | 7 +- > > > util/util.h | 6 ++ > > > 22 files changed, 284 insertions(+), 93 deletions(-) > > > > Shouldn't man pages be updated too? > > > > The man pages are up-to-date with current solution and now the code really > behaves as described to return the currently available devices. > > From man page: > "ibv_get_device_list() returns a NULL-terminated array of RDMA devices > *currently* available" > Excellent, thanks > >
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