[Fake patch] Make sysfs_dirent.s_type an unsigned short

From: Adam J. Richter (adam_at_yggdrasil.com)
Date: 12/03/04

  • Next message: Jeff Garzik: "Re: dma errors with sata_sil and Seagate disk" 
    Date:	Thu, 2 Dec 2004 19:56:28 -0800
To: maneesh@in.ibm.com

            Here is a fake patch against my heavily hacked sysfs tree
    to change sysfs_dirent.s_type from an int to an unsigned short.
    It appears next to another unsigned short (s_mode), so it should
    save 4 bytes per sysfs node.

            Note that this patch will not apply to a pristine 2.6.10-rc2-bk15
    tree, because I've moved the declaration of struct sysfs_dirent
    from include/linux/sysfs.h to fs/sysfs/sysfs.h in a previous patch.

            By the way, I have to sheepishly admit that somehow I previously
    underestimated the size of struct sysfs_dirent. Only now
    with s_children and s_count removed and s_type shortened to 16 bits
    does sysfs_dirent occupy 32 bytes, according to /proc/slabinfo.
    This does not effect my previous statements about how much memory
    is saved by each of the patches that I've posted. It just means
    the original amount of memory being used was more.

                        __ ______________
    Adam J. Richter \ /
    adam@yggdrasil.com | g g d r a s i l

    --- linux.prev/fs/sysfs/sysfs.h 2004-12-03 11:51:19.000000000 +0800
    +++ linux/fs/sysfs/sysfs.h 2004-12-03 00:51:44.000000000 +0800
    @@ -13,7 +13,7 @@
     struct sysfs_dirent {
             struct list_head s_sibling;
             void * s_element;
    - int s_type;
    + unsigned short s_type;
             umode_t s_mode;
             struct dentry * s_dentry;
     };
    -
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