Re: [PATCH 06/24] net, diet: Use small UDP hash tables on small kernels
From: Eric Dumazet <hidden>
Date: 2014-05-06 14:26:46
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On Mon, 2014-05-05 at 15:25 -0700, Andi Kleen wrote:
quoted hunk ↗ jump to hunk
From: Andi Kleen <redacted> UDP has two hash tables, for UDP and UDP lite. Default them to 16 entries each on small kernels. This can be still overriden on the command line. Signed-off-by: Andi Kleen <redacted> --- net/ipv4/udp.c | 5 +++++ 1 file changed, 5 insertions(+)diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index 4468e1a..90f967b 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c@@ -2415,7 +2415,12 @@ void udp4_proc_exit(void) } #endif /* CONFIG_PROC_FS */ +#ifdef CONFIG_BASE_SMALL +static __initdata unsigned long uhash_entries = 16; +#else static __initdata unsigned long uhash_entries; +#endif + static int __init set_uhash_entries(char *str) { ssize_t ret;
Its changed to UDP_HTABLE_SIZE_MIN later in alloc_large_system_hash() The reason there is a minimum UDP hash size is PORTS_PER_CHAIN, or DECLARE_BITMAP(bitmap, PORTS_PER_CHAIN) on stack. This patch has no effect on a small machine, because we already dynamically size this hash table. (The factor is one slot per 2MB of low memory)