From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail203.messagelabs.com (mail203.messagelabs.com [216.82.254.243]) by kanga.kvack.org (Postfix) with ESMTP id 5A55C9000BD for ; Sat, 1 Oct 2011 15:33:50 -0400 (EDT) Message-ID: <1317497626.22613.1.camel@Joe-Laptop> Subject: Re: [RFCv3][PATCH 1/4] replace string_get_size() arrays From: Joe Perches Date: Sat, 01 Oct 2011 12:33:46 -0700 In-Reply-To: <20111001000856.DD623081@kernel> References: <20111001000856.DD623081@kernel> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Mime-Version: 1.0 Sender: owner-linux-mm@kvack.org List-ID: To: Dave Hansen Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, rientjes@google.com, James.Bottomley@HansenPartnership.com, hpa@zytor.com On Fri, 2011-09-30 at 17:08 -0700, Dave Hansen wrote: > Instead of explicitly storing the entire string for each > possible units, just store the thing that varies: the > first character. trivia > 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"; u64 could be up to ~1.8**19 decimal zetta and yotta are not possible or necessary. u128 maybe someday, but then other changes would be necessary too. > +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]; index is unbounded (doesn't matter currently, it will for u128) > @@ -23,26 +40,19 @@ > int string_get_size(u64 size, const enum string_size_units units, > char *buf, int len) [] > const unsigned int divisor[] = { > [STRING_UNITS_10] = 1000, > [STRING_UNITS_2] = 1024, > }; static const or it might be better to use unsigned int divisor = (string_size_units == STRING_UNITS_2) ? 1024 : 1000; as that would make the code clearer in a couple of uses of divisor[] later. > @@ -61,7 +71,7 @@ int string_get_size(u64 size, const enum > } > > snprintf(buf, len, "%lld%s %s", (unsigned long long)size, %llu -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org