From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BE8F4ECAAD4 for ; Thu, 1 Sep 2022 02:20:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231487AbiIACUK (ORCPT ); Wed, 31 Aug 2022 22:20:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43204 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229992AbiIACUJ (ORCPT ); Wed, 31 Aug 2022 22:20:09 -0400 Received: from smtp-out1.suse.de (smtp-out1.suse.de [IPv6:2001:67c:2178:6::1c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 53F8018361; Wed, 31 Aug 2022 19:20:07 -0700 (PDT) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 2953022026; Thu, 1 Sep 2022 02:20:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1661998806; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Z5+KTbBI0lr0N4U2DBYmtt5UsQfzNdVRm+NI2VPlVFw=; b=ZcSKLBb3XeldGLBBQmnssBWgugLlWR/UmwlCRtp48ER/otLpjsR33v8bXzWsPL2/TII18b c9CaKi9P9KCcNA3VFYmf0HkW3neyH25V6iJrh1uuUdypeyovvajpsbpaiM3obt/fmUhpzX HbWkf5Dx1tXClIzInxeHo9Kos77IMkw= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1661998806; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Z5+KTbBI0lr0N4U2DBYmtt5UsQfzNdVRm+NI2VPlVFw=; b=0JSKMp2jiujV2rUgrH8rhd3FefiBDoHAikyQavStCd9WbEuz8gePjjMCvPjKLiYIr8fmCl xpZzu65KYQyVoPAA== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 671DE133DD; Thu, 1 Sep 2022 02:20:04 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id eM/0CdQWEGNCTwAAMHmgww (envelope-from ); Thu, 01 Sep 2022 02:20:04 +0000 Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3696.120.41.1.1\)) Subject: Re: [PATCH 2/3] bcache: Convert to lib/time_stats From: Coly Li In-Reply-To: <20220831173639.sb6bhg5xvn4gbkiu@moria.home.lan> Date: Thu, 1 Sep 2022 10:19:59 +0800 Cc: linux-kernel@vger.kernel.org, linux-bcache@vger.kernel.org Content-Transfer-Encoding: quoted-printable Message-Id: <20DDF7B2-8433-49EE-8F9F-CB335D2E7B6C@suse.de> References: <20220829165344.2958640-1-kent.overstreet@linux.dev> <20220829165344.2958640-3-kent.overstreet@linux.dev> <14ACCED7-D24D-4AC4-8677-F7F4630A840A@suse.de> <20220831165437.l27raas6k5nlqsdg@moria.home.lan> <1F91055C-4253-42CD-8A4A-8B8EA2CF1D6E@suse.de> <20220831173639.sb6bhg5xvn4gbkiu@moria.home.lan> To: Kent Overstreet X-Mailer: Apple Mail (2.3696.120.41.1.1) Precedence: bulk List-ID: X-Mailing-List: linux-bcache@vger.kernel.org > 2022=E5=B9=B49=E6=9C=881=E6=97=A5 01:36=EF=BC=8CKent Overstreet = =E5=86=99=E9=81=93=EF=BC=9A >=20 > On Thu, Sep 01, 2022 at 01:02:37AM +0800, Coly Li wrote: >> Can I understand that rate =3D 1/frequency ? Then frequency 4 is = around to rate 0. >=20 > Correct, rate =3D 1/frequency. >=20 >>> The quantiles are for the duration, they give you an idea of the = statistical >>> distribution, see https://en.wikipedia.org/wiki/Quantile >>=20 >> I wanted to ask how to read the quantiles line. Does it mean that 1 = ns is >> equally divided by 15 segments, and the counter values are for the = divided >> 1/15 ns segments? >=20 > It is the 15 boundaries between 16 equal segments, yes. >=20 >> Quantiles are much humane, standard deviation is scared=E2=80=A6 Just = FYI LOL. >=20 > That's valuable feedback then, maybe we'll keep both. The more = expensive part of > time stats is just ingesting data points, but we've got a percpu = buffer frontend > for that - just doing a bit more moth doesn't cost much. I don=E2=80=99t have more question so far. Thanks for the detailed = replay. Coly Li=