From mboxrd@z Thu Jan 1 00:00:00 1970 From: Benjamin Herrenschmidt Subject: Re: [PATCH 13/22] lmb: Add lmb_free_memory_size() Date: Mon, 10 May 2010 16:24:46 +1000 Message-ID: <1273472686.23699.39.camel@pasglop> References: <1273331860-14325-1-git-send-email-yinghai@kernel.org> <1273331860-14325-14-git-send-email-yinghai@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: Received: from gate.crashing.org ([63.228.1.57]:46453 "EHLO gate.crashing.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755322Ab0EJGiV (ORCPT ); Mon, 10 May 2010 02:38:21 -0400 In-Reply-To: <1273331860-14325-14-git-send-email-yinghai@kernel.org> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Yinghai Lu Cc: Ingo Molnar , Thomas Gleixner , "H. Peter Anvin" , Andrew Morton , David Miller , Linus Torvalds , Johannes Weiner , linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org On Sat, 2010-05-08 at 08:17 -0700, Yinghai Lu wrote: > It will return free memory size in specified range. > > We can not use memory_size - reserved_size here, because some reserved area > may not be in the scope of lmb.memory.region. > > Use lmb.memory.region subtracting lmb.reserved.region to get free range array. > then count size of all free ranges. The name sucks. Something like lmb_free_memory_in_range() would be better, but why do you need that in the first place ? You often tend to fail to explain why you introduce a given function, it's not always obvious and in many case I suspect they are added layers that aren't actually useful. Cheers, Ben. > Signed-off-by: Yinghai Lu > --- > include/linux/lmb.h | 1 + > mm/lmb.c | 51 +++++++++++++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 52 insertions(+), 0 deletions(-) > > diff --git a/include/linux/lmb.h b/include/linux/lmb.h > index c75d0c9..22be96d 100644 > --- a/include/linux/lmb.h > +++ b/include/linux/lmb.h > @@ -101,6 +101,7 @@ int get_free_all_memory_range(struct range **rangep, int nodeid); > void lmb_register_active_regions(int nid, unsigned long start_pfn, > unsigned long last_pfn); > u64 lmb_hole_size(u64 start, u64 end); > +u64 lmb_free_memory_size(u64 addr, u64 limit); > > #include > > diff --git a/mm/lmb.c b/mm/lmb.c > index 36b3f63..4bc125c 100644 > --- a/mm/lmb.c > +++ b/mm/lmb.c > @@ -746,6 +746,57 @@ void __init lmb_to_bootmem(u64 start, u64 end) > } > #endif > > +u64 __init lmb_free_memory_size(u64 addr, u64 limit) > +{ > + int i, count; > + struct range *range; > + int nr_range; > + u64 final_start, final_end; > + u64 free_size; > + > + count = lmb.reserved.cnt * 2; > + > + range = find_range_array(count); > + nr_range = 0; > + > + addr = PFN_UP(addr); > + limit = PFN_DOWN(limit); > + > + for (i = 0; i < lmb.memory.cnt; i++) { > + struct lmb_property *r = &lmb.memory.region[i]; > + > + final_start = PFN_UP(r->base); > + final_end = PFN_DOWN(r->base + r->size); > + if (final_start >= final_end) > + continue; > + if (final_start >= limit || final_end <= addr) > + continue; > + > + nr_range = add_range(range, count, nr_range, final_start, final_end); > + } > + subtract_range(range, count, 0, addr); > + subtract_range(range, count, limit, -1ULL); > + for (i = 0; i < lmb.reserved.cnt; i++) { > + struct lmb_property *r = &lmb.reserved.region[i]; > + > + final_start = PFN_DOWN(r->base); > + final_end = PFN_UP(r->base + r->size); > + if (final_start >= final_end) > + continue; > + if (final_start >= limit || final_end <= addr) > + continue; > + > + subtract_range(range, count, final_start, final_end); > + } > + nr_range = clean_sort_range(range, count); > + > + free_size = 0; > + for (i = 0; i < nr_range; i++) > + free_size += range[i].end - range[i].start; > + > + return free_size << PAGE_SHIFT; > +} > + > u64 __init __weak __lmb_find_area(u64 ei_start, u64 ei_last, u64 start, u64 end, > u64 size, u64 align) > {