svn commit: r295303 - head/sys/dev/hyperv/netvsc
Sepherosa Ziehau
sephe at FreeBSD.org
Fri Feb 5 05:31:33 UTC 2016
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 */
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