path: root/net/ceph
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authorIlya Dryomov <idryomov@gmail.com>2015-04-02 14:40:58 +0300
committerIlya Dryomov <idryomov@gmail.com>2015-04-07 19:08:35 +0300
commit6d7fdb0ab351b33d4c12d53fe44be030b90fc9d4 (patch)
treeb4f66c3989448a505ec465a5144b1db36ba11da4 /net/ceph
parentf22e6e847115abc3a0e2ad7bb18d243d42275af1 (diff)
Revert "libceph: use memalloc flags for net IO"
This reverts commit 89baaa570ab0b476db09408d209578cfed700e9f. Dirty page throttling should be sufficient for us in the general case so there is no need to use __GFP_MEMALLOC - it would be needed only in the swap-over-rbd case, which we currently don't support. (It would probably take approximately the commit that is being reverted to add that support, but we would also need the "swap" option to distinguish from the general case and make sure swap ceph_client-s aren't shared with anything else.) See ceph-devel threads [1] and [2] for the details of why enabling pfmemalloc reserves for all cases is a bad thing. On top of potential system lockups related to drained emergency reserves, this turned out to cause ceph lockups in case peers are on the same host and communicating via loopback due to sk_filter() dropping pfmemalloc skbs on the receiving side because the receiving loopback socket is not tagged with SOCK_MEMALLOC. [1] "SOCK_MEMALLOC vs loopback" http://www.spinics.net/lists/ceph-devel/msg22998.html [2] "[PATCH] libceph: don't set memalloc flags in loopback case" http://www.spinics.net/lists/ceph-devel/msg23392.html Conflicts: net/ceph/messenger.c [ context: tcp_nodelay option ] Cc: Mike Christie <michaelc@cs.wisc.edu> Cc: Mel Gorman <mgorman@suse.de> Cc: Sage Weil <sage@redhat.com> Cc: stable@vger.kernel.org # 3.18+, needs backporting Signed-off-by: Ilya Dryomov <idryomov@gmail.com> Acked-by: Mike Christie <michaelc@cs.wisc.edu> Acked-by: Mel Gorman <mgorman@suse.de>
Diffstat (limited to 'net/ceph')
1 files changed, 1 insertions, 8 deletions
diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
index 6b3f54ed65ba..a9f4ae45b7fb 100644
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -484,7 +484,7 @@ static int ceph_tcp_connect(struct ceph_connection *con)
IPPROTO_TCP, &sock);
if (ret)
return ret;
- sock->sk->sk_allocation = GFP_NOFS | __GFP_MEMALLOC;
+ sock->sk->sk_allocation = GFP_NOFS;
lockdep_set_class(&sock->sk->sk_lock, &socket_class);
@@ -520,8 +520,6 @@ static int ceph_tcp_connect(struct ceph_connection *con)
- sk_set_memalloc(sock->sk);
con->sock = sock;
return 0;
@@ -2808,11 +2806,8 @@ static void con_work(struct work_struct *work)
struct ceph_connection *con = container_of(work, struct ceph_connection,
- unsigned long pflags = current->flags;
bool fault;
- current->flags |= PF_MEMALLOC;
while (true) {
int ret;
@@ -2866,8 +2861,6 @@ static void con_work(struct work_struct *work)
- tsk_restore_flags(current, pflags, PF_MEMALLOC);

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