From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758236Ab1JAAJG (ORCPT ); Fri, 30 Sep 2011 20:09:06 -0400 Received: from e33.co.us.ibm.com ([32.97.110.151]:58507 "EHLO e33.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754736Ab1JAAJB (ORCPT ); Fri, 30 Sep 2011 20:09:01 -0400 Subject: [RFCv3][PATCH 1/4] replace string_get_size() arrays To: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, rientjes@google.com, James.Bottomley@HansenPartnership.com, hpa@zytor.com, Dave Hansen From: Dave Hansen Date: Fri, 30 Sep 2011 17:08:56 -0700 Message-Id: <20111001000856.DD623081@kernel> x-cbid: 11100100-2398-0000-0000-0000009FA068 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Instead of explicitly storing the entire string for each possible units, just store the thing that varies: the first character. We have to special-case the 'B' unit (index==0). This shaves about 100 bytes off of my .o file. Signed-off-by: Dave Hansen --- linux-2.6.git-dave/lib/string_helpers.c | 30 ++++++++++++++++++++---------- 1 file changed, 20 insertions(+), 10 deletions(-) diff -puN lib/string_helpers.c~string_get_size-pow2 lib/string_helpers.c --- linux-2.6.git/lib/string_helpers.c~string_get_size-pow2 2011-09-30 16:50:31.628981352 -0700 +++ linux-2.6.git-dave/lib/string_helpers.c 2011-09-30 17:04:02.211607364 -0700 @@ -8,6 +8,23 @@ #include #include +static const char byte_units[] = "_KMGTPEZY"; + +static char *__units_str(enum string_size_units unit, char *buf, int index) +{ + int place = 0; + + /* index=0 is plain 'B' with no other unit */ + if (index) { + buf[place++] = byte_units[index]; + if (unit == STRING_UNITS_2) + buf[place++] = 'i'; + } + buf[place++] = 'B'; + buf[place++] = '\0'; + return buf; +} + /** * string_get_size - get the size in the specified units * @size: The size to be converted @@ -23,26 +40,19 @@ int string_get_size(u64 size, const enum string_size_units units, char *buf, int len) { - const char *units_10[] = { "B", "kB", "MB", "GB", "TB", "PB", - "EB", "ZB", "YB", NULL}; - const char *units_2[] = {"B", "KiB", "MiB", "GiB", "TiB", "PiB", - "EiB", "ZiB", "YiB", NULL }; - const char **units_str[] = { - [STRING_UNITS_10] = units_10, - [STRING_UNITS_2] = units_2, - }; const unsigned int divisor[] = { [STRING_UNITS_10] = 1000, [STRING_UNITS_2] = 1024, }; int i, j; u64 remainder = 0, sf_cap; + char unit_buf[4]; char tmp[8]; tmp[0] = '\0'; i = 0; if (size >= divisor[units]) { - while (size >= divisor[units] && units_str[units][i]) { + while (size >= divisor[units] && (i < strlen(byte_units))) { remainder = do_div(size, divisor[units]); i++; } @@ -61,7 +71,7 @@ int string_get_size(u64 size, const enum } snprintf(buf, len, "%lld%s %s", (unsigned long long)size, - tmp, units_str[units][i]); + tmp, __units_str(units, unit_buf, i)); return 0; } diff -puN include/linux/string_helpers.h~string_get_size-pow2 include/linux/string_helpers.h _