From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9D11C35836F; Tue, 17 Mar 2026 09:12:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773738778; cv=none; b=llEzv8y2nqQ6iEjAC57CeOAu2TU789IE378WpxBrQNYNgR5ppc+tgdcx932shpvqaecFYYShAOOu6cFtUATkjjEO9P7NEBpvbxkZEjM7Yn695tHCECyS3rMBMaep5fdTgt0ydTpFhoOv6u+3TtEWnnCDCigW0o4ui185NBzOWqQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773738778; c=relaxed/simple; bh=jUm8ZaJLBgG+Muu5qS6r+UYXt4rhu3m7PbKkHZFEDvo=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=uLImGSVeg32/qbU87ezhJwKQapRYOGTIfsjRGdJ0lQIRwb75ge6H6Ao2YnSo5mUMBCYavwIhf3co0lUWaecYLKvi94YfggegJomOLUxIhDYEkwi8aUIn1Qio81LTYGssuRuRkzNgt589IGWEODeZv8Y8M68M/LMDfPBZCLuPmpU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=AG/3HAK4; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="AG/3HAK4" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=In-Reply-To:Content-Transfer-Encoding :Content-Type:MIME-Version:References:Message-ID:Subject:Cc:To:From:Date: Sender:Reply-To:Content-ID:Content-Description; bh=fJgFDdVVNtRZq/ve183e/9QuXJnpu/Eq4FFwP2YIxlQ=; b=AG/3HAK4O8ayyVuOPZnyB2Uh9P tmWEwIZEROjZynpvbdpq+DNRMbvkY2gybeTuDrtfY1/+jnWqz08TGfzJP533FGrx+D8zlGC0KK+eW 8IUU9Ycke52oz97aq7wtzygtu+Cqrfs3Ky3ics5cWclSxsoLrPtk+otIY8WuqG20IB0coqQmKBkpy H5BH34XfTk19Hd1e984MffKBwB6b+R0adtFusadkFbMEY+DB9Ab+WKP4lGH4vJVQxTesd1JJ4hTcP 7SsXxzngnle7K2ehUDtH+F6iBa2NbXTdiR1u6h3KtK094IoHBra+tjt3/4rg/rhEITBPz3pbbceiH L8dxodpA==; Received: from hch by bombadil.infradead.org with local (Exim 4.98.2 #2 (Red Hat Linux)) id 1w2QTr-00000005ouA-17Aj; Tue, 17 Mar 2026 09:12:51 +0000 Date: Tue, 17 Mar 2026 02:12:51 -0700 From: Christoph Hellwig To: changfengnan Cc: "Vlastimil Babka (SUSE)" , Dave Chinner , Harry Yoo , Hao Li , guzebing , brauner@kernel.org, djwong@kernel.org, hch@infradead.org, linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, guzebing@bytedance.com, syzbot@syzkaller.appspotmail.com, linux-mm@kvack.org Subject: Re: [PATCH v3] iomap: add allocation cache for iomap_dio Message-ID: References: <20260115021108.1913695-1-guzebing1612@gmail.com> Precedence: bulk X-Mailing-List: linux-xfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html On Tue, Mar 17, 2026 at 04:33:24PM +0800, changfengnan wrote: > > IO is not my area but getting from 1.19M to 1.20M doesn't look like it's > > worth the custom code? (possibly from 1.17M to 1.20M it also wasn't). > Yes, at least for now, there’s no need for a per-CPU. > It might be better to replace kmalloc with a new cache, but my tests so far > haven’t shown any performance improvements.  I’ll look into it further. Does using a kmem_cache help? That should generally be a nice win anyway due to keeping the objects together.