All of lore.kernel.org
 help / color / mirror / Atom feed
From: Eric Dumazet <eric.dumazet@gmail.com>
To: David Miller <davem@davemloft.net>
Cc: netdev <netdev@vger.kernel.org>,
	Neal Cardwell <ncardwell@google.com>,
	Yuchung Cheng <ycheng@google.com>
Subject: [PATCH net-next] net: set SK_MEM_QUANTUM to 4096
Date: Mon, 31 Oct 2016 11:58:40 -0700	[thread overview]
Message-ID: <1477940320.7065.312.camel@edumazet-glaptop3.roam.corp.google.com> (raw)

From: Eric Dumazet <edumazet@google.com>

Systems with large pages (64KB pages for example) do not always have
huge quantity of memory.

A big SK_MEM_QUANTUM value leads to fewer interactions with the
global counters (like tcp_memory_allocated) but might trigger
memory pressure much faster, thus suboptimal TCP performance
since windows are lowered to ridiculous values.

Signed-off-by: Eric Dumazet <edumazet@google.com>
---
 include/net/sock.h |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/include/net/sock.h b/include/net/sock.h
index f13ac87a8015cb18c5d3fe5fdcf2d6a0592428f4..d3409bb514e7f08b9cf183b7405d876bec18d732 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -1281,7 +1281,10 @@ int __sk_mem_schedule(struct sock *sk, int size, int kind);
 void __sk_mem_reduce_allocated(struct sock *sk, int amount);
 void __sk_mem_reclaim(struct sock *sk, int amount);
 
-#define SK_MEM_QUANTUM ((int)PAGE_SIZE)
+/* We used to have PAGE_SIZE here, but systems with 64KB pages
+ * do not necessarily have 16x time more memory than 4KB ones.
+ */
+#define SK_MEM_QUANTUM 4096
 #define SK_MEM_QUANTUM_SHIFT ilog2(SK_MEM_QUANTUM)
 #define SK_MEM_SEND	0
 #define SK_MEM_RECV	1

             reply	other threads:[~2016-10-31 18:58 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-10-31 18:58 Eric Dumazet [this message]
2016-10-31 19:01 ` [PATCH net-next] net: set SK_MEM_QUANTUM to 4096 Neal Cardwell
2016-10-31 19:08   ` Eric Dumazet
2016-10-31 20:32 ` [PATCH v2 " Eric Dumazet
2016-11-01  1:00   ` David Miller

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1477940320.7065.312.camel@edumazet-glaptop3.roam.corp.google.com \
    --to=eric.dumazet@gmail.com \
    --cc=davem@davemloft.net \
    --cc=ncardwell@google.com \
    --cc=netdev@vger.kernel.org \
    --cc=ycheng@google.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.