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authorEric Dumazet <edumazet@google.com>2018-10-10 22:30:00 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-10-18 10:13:24 +0300
commit7f6170683223cb38cabaff21ecbb9a6375ad10f6 (patch)
tree4cd90f7b37ec2be47b401f800bf1cc2a26b547a7 /Documentation
parent965e2adc5850836586e0961c350b94c2092da319 (diff)
downloadlinux-7f6170683223cb38cabaff21ecbb9a6375ad10f6.tar.xz
inet: frags: break the 2GB limit for frags storage
Some users are willing to provision huge amounts of memory to be able to perform reassembly reasonnably well under pressure. Current memory tracking is using one atomic_t and integers. Switch to atomic_long_t so that 64bit arches can use more than 2GB, without any cost for 32bit arches. Note that this patch avoids an overflow error, if high_thresh was set to ~2GB, since this test in inet_frag_alloc() was never true : if (... || frag_mem_limit(nf) > nf->high_thresh) Tested: $ echo 16000000000 >/proc/sys/net/ipv4/ipfrag_high_thresh <frag DDOS> $ grep FRAG /proc/net/sockstat FRAG: inuse 14705885 memory 16000002880 $ nstat -n ; sleep 1 ; nstat | grep Reas IpReasmReqds 3317150 0.0 IpReasmFails 3317112 0.0 Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> (cherry picked from commit 3e67f106f619dcfaf6f4e2039599bdb69848c714) Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/networking/ip-sysctl.txt4
1 files changed, 2 insertions, 2 deletions
diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt
index 6cd632578ce8..dbdc4130e149 100644
--- a/Documentation/networking/ip-sysctl.txt
+++ b/Documentation/networking/ip-sysctl.txt
@@ -122,10 +122,10 @@ min_adv_mss - INTEGER
IP Fragmentation:
-ipfrag_high_thresh - INTEGER
+ipfrag_high_thresh - LONG INTEGER
Maximum memory used to reassemble IP fragments.
-ipfrag_low_thresh - INTEGER
+ipfrag_low_thresh - LONG INTEGER
(Obsolete since linux-4.17)
Maximum memory used to reassemble IP fragments before the kernel
begins to remove incomplete fragment queues to free up resources.