From mboxrd@z Thu Jan 1 00:00:00 1970 From: dexen deVries Subject: Re: Applying nice/ionice to nilfs-cleanerd Date: Mon, 8 Aug 2011 12:27:54 +0200 Message-ID: <201108081227.54922.dexen.devries@gmail.com> References: <28d103cbef1f8ebb3a7b458509e53c4d@mail.shatteredsilicon.net> <201108081009.31334.dexen.devries@gmail.com> <20110808.192014.264198882.ryusuke@osrg.net> Mime-Version: 1.0 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=from:to:subject:date:user-agent:references:in-reply-to:x-face :mime-version:content-type:content-transfer-encoding:message-id; bh=LWIiIPI1SMNfl5TqxXM75AtQttCXTFLHY1jBL1xoG/w=; b=S80glxeITBSa/VoZ4GBlB8l1btcad6kqrmCj03mQmBu66lmdGEYoUSPKu25VjIn54N YlxkdZQ9+gY/CQbYfa3ug9mg9k31I/GoVNc908qdjDPeiVo779D5XtLEYFg4NPwFZWqa 23dz+pl6tdenE8IBRh7kNF3d8FcLmwKQZYInw= In-Reply-To: <20110808.192014.264198882.ryusuke-sG5X7nlA6pw@public.gmane.org> Sender: linux-nilfs-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: Text/Plain; charset="utf-8" To: linux-nilfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org On Monday 08 of August 2011 12:20:14 you wrote: > (..snip..) > Your worry and idea are ok, but this enhancement looks rather confusi= ng. >=20 > Users would misunderstand switching by the min_clean_segments_low_pri= o > threshold. >=20 > We already have mc_cleaning_interval and mc_nsegments_per_clean which > are applied when the number of clean segments is LESS than > min_clean_segments. OTOH, the low_prio_xx parameters are applied whe= n > the number of clean segments is LARGER than the > min_clean_segments_low_prio. The comparision should be inverted. agreed. > And, we already have min_clean_segments threashold. Why not just add > mc_nice and mc_ionice as below (rather than introduce the new > threthold) ? >=20 > # Sheduing priority > # if clean segments < min_clean_segments. > mc_nice -5 >=20 > # IO sheduing class and priority > # if clean segments < min_clean_segments. > mc_ionice realtime switching to faster free-space reclaimation already increases load on t= he=20 computer. If this also switched cleanerd to higher priority at the same= =20 moment, the load increase could be sharp and unpleaseant. The idea was = to have=20 three levels of cleanerd operation, rather than two. 1) slow operation 2) fast operation -- when less than min_clean_segments is available 3) fast & aggressive (high nice and ionice priority) -- when there's ev= en less=20 free space available =2E..with the hope that the 3rd level would rarely ever be reached, bec= ause the=20 2nd level would suffice most of the time. Cheers, --=20 dexen deVries [[[=E2=86=93][=E2=86=92]]] =46or example, if the first thing in the file is: an XML parser will recognize that the document is stored in the traditi= onal=20 ROT13 encoding. (( Joe English, http://www.flightlab.com/~joe/sgml/faq-not.txt )) -- To unsubscribe from this list: send the line "unsubscribe linux-nilfs" = in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html