From: Mel Gorman <mgorman@suse.de>
To: Linux-MM <linux-mm@kvack.org>, Linux-Netdev <netdev@vger.kernel.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
Mel Gorman <mgorman@suse.de>
Subject: [PATCH 11/12] nbd: Set SOCK_MEMALLOC for access to PFMEMALLOC reserves
Date: Thu, 14 Apr 2011 11:41:37 +0100 [thread overview]
Message-ID: <1302777698-28237-12-git-send-email-mgorman@suse.de> (raw)
In-Reply-To: <1302777698-28237-1-git-send-email-mgorman@suse.de>
Set SOCK_MEMALLOC on the NBD socket to allow access to PFMEMALLOC
reserves so pages backed by NBD, particularly if swap related,
can be cleaned to prevent the machine being deadlocked. It is
still possible that the PFMEMALLOC reserves get depleted resulting
in deadlock but this can be resolved by the administrator by
increasing min_free_kbytes.
Signed-off-by: Mel Gorman <mgorman@suse.de>
---
drivers/block/nbd.c | 7 ++++++-
1 files changed, 6 insertions(+), 1 deletions(-)
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index e6fc716..322cef8 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -156,6 +156,7 @@ static int sock_xmit(struct nbd_device *lo, int send, void *buf, int size,
struct msghdr msg;
struct kvec iov;
sigset_t blocked, oldset;
+ unsigned long pflags = current->flags;
if (unlikely(!sock)) {
printk(KERN_ERR "%s: Attempted %s on closed socket in sock_xmit\n",
@@ -168,8 +169,9 @@ static int sock_xmit(struct nbd_device *lo, int send, void *buf, int size,
siginitsetinv(&blocked, sigmask(SIGKILL));
sigprocmask(SIG_SETMASK, &blocked, &oldset);
+ current->flags |= PF_MEMALLOC;
do {
- sock->sk->sk_allocation = GFP_NOIO;
+ sock->sk->sk_allocation = GFP_NOIO | __GFP_MEMALLOC;
iov.iov_base = buf;
iov.iov_len = size;
msg.msg_name = NULL;
@@ -214,6 +216,7 @@ static int sock_xmit(struct nbd_device *lo, int send, void *buf, int size,
} while (size > 0);
sigprocmask(SIG_SETMASK, &oldset, NULL);
+ tsk_restore_flags(current, pflags, PF_MEMALLOC);
return result;
}
@@ -404,6 +407,8 @@ static int nbd_do_it(struct nbd_device *lo)
BUG_ON(lo->magic != LO_MAGIC);
+ sk_set_memalloc(lo->sock->sk);
+
lo->pid = current->pid;
ret = sysfs_create_file(&disk_to_dev(lo->disk)->kobj, &pid_attr.attr);
if (ret) {
--
1.7.3.4
--
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next prev parent reply other threads:[~2011-04-14 10:41 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-04-14 10:41 [PATCH 00/12] Swap-over-NBD without deadlocking v1 Mel Gorman
2011-04-14 10:41 ` [PATCH 01/12] mm: Serialize access to min_free_kbytes Mel Gorman
2011-04-14 10:41 ` [PATCH 02/12] mm: sl[au]b: Add knowledge of PFMEMALLOC reserve pages Mel Gorman
2011-04-14 10:41 ` [PATCH 03/12] mm: Introduce __GFP_MEMALLOC to allow access to emergency reserves Mel Gorman
2011-04-14 10:41 ` [PATCH 04/12] mm: allow PF_MEMALLOC from softirq context Mel Gorman
2011-04-14 10:41 ` [PATCH 05/12] mm: Ignore mempolicies when using ALLOC_NO_WATERMARK Mel Gorman
2011-04-14 10:41 ` [PATCH 06/12] net: Introduce sk_allocation() to allow addition of GFP flags depending on the individual socket Mel Gorman
2011-04-14 10:41 ` [PATCH 07/12] netvm: Allow the use of __GFP_MEMALLOC by specific sockets Mel Gorman
2011-04-14 10:41 ` [PATCH 08/12] netvm: Allow skb allocation to use PFMEMALLOC reserves Mel Gorman
2011-04-14 21:33 ` David Miller
2011-04-15 10:44 ` Mel Gorman
2011-04-14 10:41 ` [PATCH 09/12] netvm: Set PF_MEMALLOC as appropriate during SKB processing Mel Gorman
2011-04-14 10:41 ` [PATCH 10/12] mm: Micro-optimise slab to avoid a function call Mel Gorman
2011-04-14 10:41 ` Mel Gorman [this message]
2011-04-14 10:41 ` [PATCH 12/12] mm: Throttle direct reclaimers if PF_MEMALLOC reserves are low and swap is backed by network storage Mel Gorman
2011-04-18 12:30 ` NeilBrown
2011-04-18 14:04 ` Mel Gorman
2011-04-18 12:32 ` NeilBrown
2011-04-18 14:08 ` Mel Gorman
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