| Message ID | 1450358340-19361-7-git-send-email-ogerlitz@mellanox.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
I do have a holistic view on this and similar patches to avoid calling ib_query_xyz(). Caching logic has been introduced in ibcore (cache.c). It does, however, provide a non-transparent call to ib_query_xyz() attributes, e.g., ib_get_cached_gid(). On my opinion, caching should be transparent. (When caching in CPUs were introduced, we could still use the same instructions, right?) So, my proposal would be to make the ib_query_xyz() fast, by have _its_ implementations using a cache. This can be done by changing a single statement per query, and it will take effect for all clients and ULPs: Change ib_query_xyz() to call ib_get_cache_xyz() instead of device->query_xyz(). This way, all legacy calls to ib_query_xyz() will use the cached version and no changes are required in ULPs / clients. The complication is to update the cache properly before events are forwarded, but I think that can be done failry simply. My 2 cents. Thxs, Håkon > On 17. des. 2015, at 14.19, Or Gerlitz <ogerlitz@mellanox.com> wrote: > > Instead, use the cached copy of the attributes present on the device. > > Based on a patch from Christoph Hellwig <hch@lst.de> > > Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com> > --- > drivers/staging/lustre/lnet/klnds/o2iblnd/o2iblnd.c | 21 +-------------------- > 1 file changed, 1 insertion(+), 20 deletions(-) > > diff --git a/drivers/staging/lustre/lnet/klnds/o2iblnd/o2iblnd.c b/drivers/staging/lustre/lnet/klnds/o2iblnd/o2iblnd.c > index 7c730e3..7231ef8 100644 > --- a/drivers/staging/lustre/lnet/klnds/o2iblnd/o2iblnd.c > +++ b/drivers/staging/lustre/lnet/klnds/o2iblnd/o2iblnd.c > @@ -2070,32 +2070,13 @@ static int kiblnd_net_init_pools(kib_net_t *net, __u32 *cpts, int ncpts) > > static int kiblnd_hdev_get_attr(kib_hca_dev_t *hdev) > { > - struct ib_device_attr *attr; > - int rc; > - > /* It's safe to assume a HCA can handle a page size > * matching that of the native system */ > hdev->ibh_page_shift = PAGE_SHIFT; > hdev->ibh_page_size = 1 << PAGE_SHIFT; > hdev->ibh_page_mask = ~((__u64)hdev->ibh_page_size - 1); > > - LIBCFS_ALLOC(attr, sizeof(*attr)); > - if (attr == NULL) { > - CERROR("Out of memory\n"); > - return -ENOMEM; > - } > - > - rc = ib_query_device(hdev->ibh_ibdev, attr); > - if (rc == 0) > - hdev->ibh_mr_size = attr->max_mr_size; > - > - LIBCFS_FREE(attr, sizeof(*attr)); > - > - if (rc != 0) { > - CERROR("Failed to query IB device: %d\n", rc); > - return rc; > - } > - > + hdev->ibh_mr_size = hdev->ibh_ibdev->attrs.max_mr_size; > if (hdev->ibh_mr_size == ~0ULL) { > hdev->ibh_mr_shift = 64; > return 0; > -- > 2.3.7 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-rdma" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/staging/lustre/lnet/klnds/o2iblnd/o2iblnd.c b/drivers/staging/lustre/lnet/klnds/o2iblnd/o2iblnd.c index 7c730e3..7231ef8 100644 --- a/drivers/staging/lustre/lnet/klnds/o2iblnd/o2iblnd.c +++ b/drivers/staging/lustre/lnet/klnds/o2iblnd/o2iblnd.c @@ -2070,32 +2070,13 @@ static int kiblnd_net_init_pools(kib_net_t *net, __u32 *cpts, int ncpts) static int kiblnd_hdev_get_attr(kib_hca_dev_t *hdev) { - struct ib_device_attr *attr; - int rc; - /* It's safe to assume a HCA can handle a page size * matching that of the native system */ hdev->ibh_page_shift = PAGE_SHIFT; hdev->ibh_page_size = 1 << PAGE_SHIFT; hdev->ibh_page_mask = ~((__u64)hdev->ibh_page_size - 1); - LIBCFS_ALLOC(attr, sizeof(*attr)); - if (attr == NULL) { - CERROR("Out of memory\n"); - return -ENOMEM; - } - - rc = ib_query_device(hdev->ibh_ibdev, attr); - if (rc == 0) - hdev->ibh_mr_size = attr->max_mr_size; - - LIBCFS_FREE(attr, sizeof(*attr)); - - if (rc != 0) { - CERROR("Failed to query IB device: %d\n", rc); - return rc; - } - + hdev->ibh_mr_size = hdev->ibh_ibdev->attrs.max_mr_size; if (hdev->ibh_mr_size == ~0ULL) { hdev->ibh_mr_shift = 64; return 0;
Instead, use the cached copy of the attributes present on the device. Based on a patch from Christoph Hellwig <hch@lst.de> Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com> --- drivers/staging/lustre/lnet/klnds/o2iblnd/o2iblnd.c | 21 +-------------------- 1 file changed, 1 insertion(+), 20 deletions(-)