From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f200.google.com (mail-pf0-f200.google.com [209.85.192.200]) by kanga.kvack.org (Postfix) with ESMTP id 307A36B000A for ; Tue, 6 Mar 2018 02:07:01 -0500 (EST) Received: by mail-pf0-f200.google.com with SMTP id t24so9724703pfe.20 for ; Mon, 05 Mar 2018 23:07:01 -0800 (PST) Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id c10sor2868073pgn.268.2018.03.05.23.06.59 for (Google Transport Security); Mon, 05 Mar 2018 23:06:59 -0800 (PST) From: Sergey Senozhatsky Subject: [PATCHv2 2/2] zram: drop max_zpage_size and use zs_huge_class_size() Date: Tue, 6 Mar 2018 16:06:39 +0900 Message-Id: <20180306070639.7389-3-sergey.senozhatsky@gmail.com> In-Reply-To: <20180306070639.7389-1-sergey.senozhatsky@gmail.com> References: <20180306070639.7389-1-sergey.senozhatsky@gmail.com> Sender: owner-linux-mm@kvack.org List-ID: To: Minchan Kim , Andrew Morton Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Sergey Senozhatsky , Sergey Senozhatsky , Mike Rapoport This patch removes ZRAM's enforced "huge object" value and uses zsmalloc huge-class watermark instead, which makes more sense. TEST - I used a 1G zram device, LZO compression back-end, original data set size was 444MB. Looking at zsmalloc classes stats the test ended up to be pretty fair. BASE ZRAM/ZSMALLOC ===================== zram mm_stat 498978816 191482495 199831552 0 199831552 15634 0 zsmalloc classes class size almost_full almost_empty obj_allocated obj_used pages_used pages_per_zspage freeable ... 151 2448 0 0 1240 1240 744 3 0 168 2720 0 0 4200 4200 2800 2 0 190 3072 0 0 10100 10100 7575 3 0 202 3264 0 0 380 380 304 4 0 254 4096 0 0 10620 10620 10620 1 0 Total 7 46 106982 106187 48787 0 PATCHED ZRAM/ZSMALLOC ===================== zram mm_stat 498978816 182579184 194248704 0 194248704 15628 0 zsmalloc classes class size almost_full almost_empty obj_allocated obj_used pages_used pages_per_zspage freeable ... 151 2448 0 0 1240 1240 744 3 0 168 2720 0 0 4200 4200 2800 2 0 190 3072 0 0 10100 10100 7575 3 0 202 3264 0 0 7180 7180 5744 4 0 254 4096 0 0 3820 3820 3820 1 0 Total 8 45 106959 106193 47424 0 As we can see, we reduced the number of objects stored in class-4096, because a huge number of objects which we previously forcibly stored in class-4096 now stored in non-huge class-3264. This results in lower memory consumption: - zsmalloc now uses 47424 physical pages, which is less than 48787 pages zsmalloc used before. - objects that we store in class-3264 share zspages. That's why overall the number of pages that both class-4096 and class-3264 consumed went down from 10924 to 9564. Signed-off-by: Sergey Senozhatsky --- drivers/block/zram/zram_drv.c | 9 ++++++++- drivers/block/zram/zram_drv.h | 16 ---------------- 2 files changed, 8 insertions(+), 17 deletions(-) diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 85110e7931e5..1b8082e6d2f5 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -44,6 +44,11 @@ static const char *default_compressor = "lzo"; /* Module params (documentation at end) */ static unsigned int num_devices = 1; +/* + * Pages that compress to sizes equals or greater than this are stored + * uncompressed in memory. + */ +static size_t huge_class_size; static void zram_free_page(struct zram *zram, size_t index); @@ -786,6 +791,8 @@ static bool zram_meta_alloc(struct zram *zram, u64 disksize) return false; } + if (!huge_class_size) + huge_class_size = zs_huge_class_size(); return true; } @@ -965,7 +972,7 @@ static int __zram_bvec_write(struct zram *zram, struct bio_vec *bvec, return ret; } - if (unlikely(comp_len > max_zpage_size)) { + if (unlikely(comp_len >= huge_class_size)) { if (zram_wb_enabled(zram) && allow_wb) { zcomp_stream_put(zram->comp); ret = write_to_bdev(zram, bvec, index, bio, &element); diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h index 31762db861e3..d71c8000a964 100644 --- a/drivers/block/zram/zram_drv.h +++ b/drivers/block/zram/zram_drv.h @@ -21,22 +21,6 @@ #include "zcomp.h" -/*-- Configurable parameters */ - -/* - * Pages that compress to size greater than this are stored - * uncompressed in memory. - */ -static const size_t max_zpage_size = PAGE_SIZE / 4 * 3; - -/* - * NOTE: max_zpage_size must be less than or equal to: - * ZS_MAX_ALLOC_SIZE. Otherwise, zs_malloc() would - * always return failure. - */ - -/*-- End of configurable params */ - #define SECTOR_SHIFT 9 #define SECTORS_PER_PAGE_SHIFT (PAGE_SHIFT - SECTOR_SHIFT) #define SECTORS_PER_PAGE (1 << SECTORS_PER_PAGE_SHIFT) -- 2.16.2 -- 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/ . Don't email: email@kvack.org