From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: xmm2 - monitor Linux MM active/inactive lists graphically References: Reply-To: zlatko.calusic@iskon.hr From: Zlatko Calusic Date: 26 Oct 2001 11:45:55 +0200 In-Reply-To: (Linus Torvalds's message of "Thu, 25 Oct 2001 09:31:12 -0700 (PDT)") Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: owner-linux-mm@kvack.org Return-Path: To: Linus Torvalds Cc: Marcelo Tosatti , linux-mm@kvack.org, lkml List-ID: Linus Torvalds writes: > On 25 Oct 2001, Zlatko Calusic wrote: > > > > Yes, I definitely have DMA turned ON. All parameters are OK. :) > > I suspect it may just be that "queue_nr_requests"/"batch_count" is > different in -ac: what happens if you tweak them to the same values? > > (See drivers/block/ll_rw_block.c) > > I think -ac made the queues a bit deeper the regular kernel does 128 > requests and a batch-count of 16, I _think_ -ac does something like "2 > requests per megabyte" and batch_count=32, so if you have 512MB you should > try with > > queue_nr_requests = 1024 > batch_count = 32 > > Does that help? > Unfortunately not. It makes a machine quite unresponsive while it's writing to disk, and vmstat 1 discovers strange "spiky" behaviour. Average throughput is ~ 8MB/s (disk is capable of ~ 13MB/s) procs memory swap io system cpu r b w swpd free buff cache si so bi bo in cs us sy id 2 0 0 0 3840 528 441900 0 0 0 34816 188 594 2 34 64 0 1 0 0 3332 536 442384 0 0 4 10624 187 519 2 8 90 0 1 0 0 3324 536 442384 0 0 0 0 182 499 0 0 100 2 1 0 0 3300 536 442384 0 0 0 0 198 486 0 1 99 1 1 0 0 3304 536 442384 0 0 0 0 186 513 0 0 100 0 1 1 0 3304 536 442384 0 0 0 0 193 473 0 1 99 0 1 1 0 3304 536 442384 0 0 0 0 191 508 1 1 98 0 1 0 0 3884 536 441840 0 0 4 44672 189 590 4 40 56 0 1 0 0 3860 536 441840 0 0 0 0 186 526 0 1 99 0 1 0 0 3852 536 441840 0 0 0 0 191 500 0 0 100 0 1 0 0 3844 536 441840 0 0 0 0 193 482 1 0 99 0 1 0 0 3844 536 441840 0 0 0 0 187 511 0 1 99 0 2 1 0 3832 540 441844 0 0 4 0 305 1004 3 2 95 0 3 1 0 3824 544 441844 0 0 4 0 410 1340 2 2 96 0 3 0 0 3764 552 441916 0 0 12 47360 346 915 6 41 53 0 3 0 0 3764 552 441916 0 0 0 0 373 887 0 0 100 0 3 0 0 3764 552 441916 0 0 0 0 278 692 1 2 97 1 3 0 0 3764 552 441916 0 0 0 0 221 579 0 3 97 0 3 0 0 3764 552 441916 0 0 0 0 286 704 0 2 98 I'll now test "batch_count = queue_nr_requests / 3", which I found in 2.4.14-pre2, but with queue_nr_request still left at 1024. And report results after that. -- Zlatko -- 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/