Author: sephe Date: Fri Feb 5 05:31:31 2016 New Revision: 295303 URL: https://svnweb.freebsd.org/changeset/base/295303
Log: hyperv/hn: Recover half of the chimney sending space We lost half of the chimney sending space, because we mis-used ffs() on a 64 bits mask, where ffsl() should be used. While I'm here: - Use system atomic operation instead. - Stringent chimney sending index assertion. Reviewed by: adrian Approved by: adrian (mentor) MFC after: 1 week Sponsored by: Microsoft OSTC Differential Revision: https://reviews.freebsd.org/D5159 Modified: head/sys/dev/hyperv/netvsc/hv_net_vsc.c Modified: head/sys/dev/hyperv/netvsc/hv_net_vsc.c ============================================================================== --- head/sys/dev/hyperv/netvsc/hv_net_vsc.c Fri Feb 5 05:25:11 2016 (r295302) +++ head/sys/dev/hyperv/netvsc/hv_net_vsc.c Fri Feb 5 05:31:31 2016 (r295303) @@ -136,15 +136,15 @@ hv_nv_get_next_send_section(netvsc_dev * int i; for (i = 0; i < bitsmap_words; i++) { - idx = ffs(~bitsmap[i]); + idx = ffsl(~bitsmap[i]); if (0 == idx) continue; idx--; - if (i * BITS_PER_LONG + idx >= net_dev->send_section_count) - return (ret); + KASSERT(i * BITS_PER_LONG + idx < net_dev->send_section_count, + ("invalid i %d and idx %lu", i, idx)); - if (synch_test_and_set_bit(idx, &bitsmap[i])) + if (atomic_testandset_long(&bitsmap[i], idx)) continue; ret = i * BITS_PER_LONG + idx; @@ -789,8 +789,27 @@ hv_nv_on_send_completion(netvsc_dev *net if (NULL != net_vsc_pkt) { if (net_vsc_pkt->send_buf_section_idx != NVSP_1_CHIMNEY_SEND_INVALID_SECTION_INDEX) { - synch_change_bit(net_vsc_pkt->send_buf_section_idx, - net_dev->send_section_bitsmap); + u_long mask; + int idx; + + idx = net_vsc_pkt->send_buf_section_idx / + BITS_PER_LONG; + KASSERT(idx < net_dev->bitsmap_words, + ("invalid section index %u", + net_vsc_pkt->send_buf_section_idx)); + mask = 1UL << + (net_vsc_pkt->send_buf_section_idx % + BITS_PER_LONG); + + KASSERT(net_dev->send_section_bitsmap[idx] & + mask, + ("index bitmap 0x%lx, section index %u, " + "bitmap idx %d, bitmask 0x%lx", + net_dev->send_section_bitsmap[idx], + net_vsc_pkt->send_buf_section_idx, + idx, mask)); + atomic_clear_long( + &net_dev->send_section_bitsmap[idx], mask); } /* Notify the layer above us */ _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
