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Thu, 28 May 2020 15:18:23 -0700 (PDT) Date: Thu, 28 May 2020 22:18:22 +0000 From: Wei Yang To: Andrew Morton Cc: Wei Yang , Andy Shevchenko , Jesse Brandeburg , christian.brauner@ubuntu.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH] bitops: simplify get_count_order_long() Message-ID: <20200528221822.icstykoyppbeznzs@master> Reply-To: Wei Yang References: <20200524123551.9469-1-richard.weiyang@gmail.com> <20200525091458.GK1634618@smile.fi.intel.com> <20200525144312.mbw2z3ydncyasvss@master> <20200525153216.GD1634618@smile.fi.intel.com> <20200525134110.5737dd603d5fa1230e2f7ece@linux-foundation.org> <20200525215741.zd3gry4yyqqplix6@master> <20200525153146.c1337b1ca7af386ac30e5702@linux-foundation.org> <20200527224542.yx45druzqtlaxrl7@master> <20200527160508.2ef29d6904c07ca6c650638c@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200527160508.2ef29d6904c07ca6c650638c@linux-foundation.org> User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, May 27, 2020 at 04:05:08PM -0700, Andrew Morton wrote: >On Wed, 27 May 2020 22:45:42 +0000 Wei Yang wrote: > >> /* a tiny module only meant to test get_count_order/long */ >> unsigned int order_comb[][2] = { >> {0x00000003, 2}, >> {0x00000004, 2}, >> {0x00001fff, 13}, >> {0x00002000, 13}, >> {0x50000000, 32}, >> {0x80000000, 32}, >> }; >> >> static int __init test_getorder_startup(void) >> { >> int i; >> >> for (i = 0; i < ARRAY_SIZE(order_comb); i++) { >> if (order_comb[i][1] != get_count_order(order_comb[i][0])) >> pr_warn("get_count_order wrong for %lx\n", >> order_comb[i][0]); >> } >> >> return 0; >> } >> >> Since I don't get a way to iterate all the possibilities, some random >> combination is chosen. Is this one looks good? > >Looks good. > >You might want to add a less-negative number as well? 0x80030000. >Something that won't turn positive if it has 1 subtracted from it. Thanks, this is a good suggestion. -- Wei Yang Help you, Help me