[PATCH openEuler-1.0-LTS 0/2] net: dst: Optimized route gc
Eric Dumazet (1): net/dst: use a smaller percpu_counter batch for dst entries accounting Peter Oskolkov (1): net: add a route cache full diagnostic message include/net/dst_ops.h | 4 +++- net/core/dst.c | 8 ++++++-- net/ipv6/route.c | 3 +++ 3 files changed, 12 insertions(+), 3 deletions(-) -- 2.25.1
From: Peter Oskolkov <posk@google.com> stable inclusion from stable-v4.19.304 commit 47468fae2704151503214f4d4327c164118247fd category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I90HST Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- commit 22c2ad616b74f3de2256b242572ab449d031d941 upstream. In some testing scenarios, dst/route cache can fill up so quickly that even an explicit GC call occasionally fails to clean it up. This leads to sporadically failing calls to dst_alloc and "network unreachable" errors to the user, which is confusing. This patch adds a diagnostic message to make the cause of the failure easier to determine. Signed-off-by: Peter Oskolkov <posk@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Suraj Jitindar Singh <surajjs@amazon.com> Cc: <stable@vger.kernel.org> # 4.19.x Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Dong Chenchen <dongchenchen2@huawei.com> --- net/core/dst.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/net/core/dst.c b/net/core/dst.c index 81ccf20e2826..a263309df115 100644 --- a/net/core/dst.c +++ b/net/core/dst.c @@ -98,8 +98,12 @@ void *dst_alloc(struct dst_ops *ops, struct net_device *dev, struct dst_entry *dst; if (ops->gc && dst_entries_get_fast(ops) > ops->gc_thresh) { - if (ops->gc(ops)) + if (ops->gc(ops)) { + printk_ratelimited(KERN_NOTICE "Route cache is full: " + "consider increasing sysctl " + "net.ipv[4|6].route.max_size.\n"); return NULL; + } } dst = kmem_cache_alloc(ops->kmem_cachep, GFP_ATOMIC); -- 2.25.1
From: Eric Dumazet <edumazet@google.com> stable inclusion from stable-v4.19.304 commit 9635bd0a5296e2e725c6b33e530d0ef582e2f64e category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I90HST Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- commit cf86a086a18095e33e0637cb78cda1fcf5280852 upstream. percpu_counter_add() uses a default batch size which is quite big on platforms with 256 cpus. (2*256 -> 512) This means dst_entries_get_fast() can be off by +/- 2*(nr_cpus^2) (131072 on servers with 256 cpus) Reduce the batch size to something more reasonable, and add logic to ip6_dst_gc() to call dst_entries_get_slow() before calling the _very_ expensive fib6_run_gc() function. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Suraj Jitindar Singh <surajjs@amazon.com> Cc: <stable@vger.kernel.org> # 4.19.x Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Dong Chenchen <dongchenchen2@huawei.com> --- include/net/dst_ops.h | 4 +++- net/core/dst.c | 8 ++++---- net/ipv6/route.c | 3 +++ 3 files changed, 10 insertions(+), 5 deletions(-) diff --git a/include/net/dst_ops.h b/include/net/dst_ops.h index 33392b9a701f..b8ee48ea07f1 100644 --- a/include/net/dst_ops.h +++ b/include/net/dst_ops.h @@ -63,9 +63,11 @@ static inline int dst_entries_get_slow(struct dst_ops *dst) return percpu_counter_sum_positive(&dst->pcpuc_entries); } +#define DST_PERCPU_COUNTER_BATCH 32 static inline void dst_entries_add(struct dst_ops *dst, int val) { - percpu_counter_add(&dst->pcpuc_entries, val); + percpu_counter_add_batch(&dst->pcpuc_entries, val, + DST_PERCPU_COUNTER_BATCH); } static inline int dst_entries_init(struct dst_ops *dst) diff --git a/net/core/dst.c b/net/core/dst.c index a263309df115..1a9f84f8cde1 100644 --- a/net/core/dst.c +++ b/net/core/dst.c @@ -97,11 +97,11 @@ void *dst_alloc(struct dst_ops *ops, struct net_device *dev, { struct dst_entry *dst; - if (ops->gc && dst_entries_get_fast(ops) > ops->gc_thresh) { + if (ops->gc && + !(flags & DST_NOCOUNT) && + dst_entries_get_fast(ops) > ops->gc_thresh) { if (ops->gc(ops)) { - printk_ratelimited(KERN_NOTICE "Route cache is full: " - "consider increasing sysctl " - "net.ipv[4|6].route.max_size.\n"); + pr_notice_ratelimited("Route cache is full: consider increasing sysctl net.ipv6.route.max_size.\n"); return NULL; } } diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 7b2ed1fb747e..344e1548fd94 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -2781,6 +2781,9 @@ static int ip6_dst_gc(struct dst_ops *ops) int entries; entries = dst_entries_get_fast(ops); + if (entries > rt_max_size) + entries = dst_entries_get_slow(ops); + if (time_after(rt_last_gc + rt_min_interval, jiffies) && entries <= rt_max_size) goto out; -- 2.25.1
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