From: Johannes Berg <johannes@sipsolutions.net>
To: linux-wireless@vger.kernel.org
Cc: Jiri Benc <jbenc@suse.cz>, Michael Wu <flamingice@sourmilk.net>,
"John W. Linville" <linville@tuxdriver.com>
Subject: [PATCH] conserve stack space due to padding
Date: Thu, 14 Jun 2007 09:26:11 +0200 [thread overview]
Message-ID: <1181805971.9058.14.camel@johannes.berg> (raw)
This patch reorders some fields in struct ieee802_11_elems to save 17*7
or 17*3 bytes (on 64/32-bit machines respectively) stack space in a few
functions.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
---
I don't think this hurts readability at all since these things are
*very* structured to begin with. And having 8/4 byte fields alternate
with 1 byte fields isn't such a great idea.
net/mac80211/ieee80211_sta.c | 35 +++++++++++++++++++----------------
1 file changed, 19 insertions(+), 16 deletions(-)
--- wireless-dev.orig/net/mac80211/ieee80211_sta.c 2007-06-14 09:19:48.780669913 +0200
+++ wireless-dev/net/mac80211/ieee80211_sta.c 2007-06-14 09:21:28.720669913 +0200
@@ -79,39 +79,42 @@ static int ieee80211_sta_config_auth(str
/* Parsed Information Elements */
struct ieee802_11_elems {
+ /* pointers to IEs */
u8 *ssid;
- u8 ssid_len;
u8 *supp_rates;
- u8 supp_rates_len;
u8 *fh_params;
- u8 fh_params_len;
u8 *ds_params;
- u8 ds_params_len;
u8 *cf_params;
- u8 cf_params_len;
u8 *tim;
- u8 tim_len;
u8 *ibss_params;
- u8 ibss_params_len;
u8 *challenge;
- u8 challenge_len;
u8 *wpa;
- u8 wpa_len;
u8 *rsn;
- u8 rsn_len;
u8 *erp_info;
- u8 erp_info_len;
u8 *ht_cap_param;
- u8 ht_cap_param_len;
u8 *ht_extra_param;
- u8 ht_extra_param_len;
u8 *ext_supp_rates;
- u8 ext_supp_rates_len;
u8 *wmm_info;
- u8 wmm_info_len;
u8 *wmm_param;
- u8 wmm_param_len;
u8 *tspec;
+
+ /* length of them, respectively */
+ u8 ssid_len;
+ u8 supp_rates_len;
+ u8 fh_params_len;
+ u8 ds_params_len;
+ u8 cf_params_len;
+ u8 tim_len;
+ u8 ibss_params_len;
+ u8 challenge_len;
+ u8 wpa_len;
+ u8 rsn_len;
+ u8 erp_info_len;
+ u8 ht_cap_param_len;
+ u8 ht_extra_param_len;
+ u8 ext_supp_rates_len;
+ u8 wmm_info_len;
+ u8 wmm_param_len;
u8 tspec_len;
};
next reply other threads:[~2007-06-14 9:08 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-06-14 7:26 Johannes Berg [this message]
2007-06-15 13:30 ` [PATCH] conserve stack space due to padding Jiri Benc
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