From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk0-f182.google.com (mail-qk0-f182.google.com [209.85.220.182]) by kanga.kvack.org (Postfix) with ESMTP id 16C2F6B0038 for ; Tue, 18 Aug 2015 15:21:47 -0400 (EDT) Received: by qkfj126 with SMTP id j126so62128192qkf.0 for ; Tue, 18 Aug 2015 12:21:46 -0700 (PDT) Received: from mail-qg0-x229.google.com (mail-qg0-x229.google.com. [2607:f8b0:400d:c04::229]) by mx.google.com with ESMTPS id 77si6100968qhu.22.2015.08.18.12.21.46 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 18 Aug 2015 12:21:46 -0700 (PDT) Received: by qgeg42 with SMTP id g42so125828118qge.1 for ; Tue, 18 Aug 2015 12:21:46 -0700 (PDT) From: Dan Streetman Subject: [PATCH] zswap: move zswap_pool frequently-used fields together Date: Tue, 18 Aug 2015 15:21:41 -0400 Message-Id: <1439925701-29678-1-git-send-email-ddstreet@ieee.org> Sender: owner-linux-mm@kvack.org List-ID: To: Seth Jennings , Andrew Morton Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Sergey Senozhatsky , Dan Streetman Move the "tfm" field in struct zswap_pool to the top, after the "zpool" field. As suggested by Sergey Senozhatsky: >> > ->tfm will be access pretty often, right? did you intentionally put it >> > at the bottom offset of `struct zswap_pool'? >> >> no it wasn't intentional; does moving it up provide a benefit? > > well, I just prefer to keep 'read mostly' pointers together. all > those cache lines, etc. > > gcc 5.1, x86_64 > > struct zswap_pool { > struct zpool *zpool; > + struct crypto_comp * __percpu *tfm; > struct kref kref; > struct list_head list; > struct rcu_head rcu_head; > struct notifier_block notifier; > char tfm_name[CRYPTO_MAX_ALG_NAME]; > - struct crypto_comp * __percpu *tfm; > }; > > ../scripts/bloat-o-meter zswap.o.old zswap.o > add/remove: 0/0 grow/shrink: 0/6 up/down: 0/-27 (-27) > function old new delta > zswap_writeback_entry 659 656 -3 > zswap_frontswap_store 1445 1442 -3 > zswap_frontswap_load 417 414 -3 > zswap_pool_create 438 432 -6 > __zswap_cpu_comp_notifier.part 152 146 -6 > __zswap_cpu_comp_notifier 122 116 -6 Suggested-by: Sergey Senozhatsky Signed-off-by: Dan Streetman --- mm/zswap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/zswap.c b/mm/zswap.c index b198081..4043df7 100644 --- a/mm/zswap.c +++ b/mm/zswap.c @@ -120,12 +120,12 @@ module_param_named(max_pool_percent, zswap_max_pool_percent, uint, 0644); struct zswap_pool { struct zpool *zpool; + struct crypto_comp * __percpu *tfm; struct kref kref; struct list_head list; struct rcu_head rcu_head; struct notifier_block notifier; char tfm_name[CRYPTO_MAX_ALG_NAME]; - struct crypto_comp * __percpu *tfm; }; /* -- 2.1.0 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org