From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: [PATCH] mm: reorder struct bio to remove padding on 64bit From: Richard Kennedy Content-Type: text/plain Date: Thu, 27 Nov 2008 12:03:17 +0000 Message-Id: <1227787397.3120.7.camel@castor.localdomain> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: neilb@suse.de Cc: lkml , linux-mm List-ID: remove 8 bytes of padding from struct bio which also removes 16 bytes from struct bio_pair to make it 248 bytes. bio_pair then fits into one fewer cache lines & into a smaller slab. Signed-off-by: Richard Kennedy --- Hi Neil, This compiles but hasn't had any testing, as I don't have a raid to test it on. patch against 2.6.28-rc6. regards Richard diff --git a/include/linux/bio.h b/include/linux/bio.h index 6a64209..e6789b2 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -90,10 +90,11 @@ struct bio { unsigned int bi_comp_cpu; /* completion CPU */ + atomic_t bi_cnt; /* pin count */ + struct bio_vec *bi_io_vec; /* the actual vec list */ bio_end_io_t *bi_end_io; - atomic_t bi_cnt; /* pin count */ void *bi_private; #if defined(CONFIG_BLK_DEV_INTEGRITY) -- 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