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charset="UTF-8" ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1660638544; a=rsa-sha256; cv=none; b=Rf+iP4DfPu7Tq5l6M0ctGVzQ3rMSzVdc9f6MPqSfMUBNCebD5rKQXR5vrenvigo9YGmMA+ mrsL4NnHLdG0SApZRL49qAiNf6TVo638avevJgVQv1kdpVYtZBYap8hKsGaWiXa5IrKd7H tF5VwuOTPBJVxSyAG9EEWrZVeCeJ2kA= ARC-Authentication-Results: i=1; imf08.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=BcZI6X0e; spf=pass (imf08.hostedemail.com: domain of huang.ying.caritas@gmail.com designates 209.85.217.45 as permitted sender) smtp.mailfrom=huang.ying.caritas@gmail.com; dmarc=pass (policy=none) header.from=gmail.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1660638544; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=5+JNREwE1A4uHAEmXDcDFaNJYYYR64QtVhTwaoPWxKs=; b=WUDGUZ3pYarwXslNabXkRyl1T914DJs5i5aBL/3w2XKcVZYNR92we0XWQBPYqVjLZ6yPNF etdsLIvBgGAoYldcD9yT9T542FVGeQQFFUXnaP2Lznom4Qjudoe3xUQrdOi+fdkoJun+fQ SLXl4F+/TzIlBbdzKRbeMu0TEToUOXU= X-Stat-Signature: mkoxw7mqp9qt64q1uc6bx83ki17umwex X-Rspamd-Queue-Id: 4CD77160033 Authentication-Results: imf08.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=BcZI6X0e; spf=pass (imf08.hostedemail.com: domain of huang.ying.caritas@gmail.com designates 209.85.217.45 as permitted sender) smtp.mailfrom=huang.ying.caritas@gmail.com; dmarc=pass (policy=none) header.from=gmail.com X-Rspam-User: X-Rspamd-Server: rspam03 X-HE-Tag: 1660638544-616886 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Fri, Aug 12, 2022 at 1:58 PM Aneesh Kumar K.V wrote: [snip] > diff --git a/include/linux/memory-tiers.h b/include/linux/memory-tiers.h > new file mode 100644 > index 000000000000..bc7c1b799bef > --- /dev/null > +++ b/include/linux/memory-tiers.h > @@ -0,0 +1,15 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > +#ifndef _LINUX_MEMORY_TIERS_H > +#define _LINUX_MEMORY_TIERS_H > + > +/* > + * Each tier cover a abstrace distance chunk size of 128 > + */ > +#define MEMTIER_CHUNK_BITS 7 > +#define MEMTIER_CHUNK_SIZE (1 << MEMTIER_CHUNK_BITS) > +/* > + * Smaller abstract distance value imply faster(higher) memory tiers. > + */ > +#define MEMTIER_ADISTANCE_DRAM (4 * MEMTIER_CHUNK_SIZE) This will make the abstract distance of DRAM the start of its memory tier. So that any memory type that is slightly slower than DRAM will be put in a lower memory tier. So I think it's better to put the DRAM at the middle of its memory tier by default. For example, 4 * MEMTIER_CHUNK_SIZE + MEMTIER_CHUNK_SIZE / 2 > + > +#endif /* _LINUX_MEMORY_TIERS_H */ [snip] Best Regards, Huang, Ying