From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.223.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 88D301527AE for ; Thu, 2 May 2024 06:45:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=195.135.223.131 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714632338; cv=none; b=JZsNeCsF6iL2Gp8SJIRQUhWQyUgMf62RDMA2m52rSN4fU1FwM9oSAOF8aNQWQVlG4F6US3qKlpUbAPuqBSszeA7x0ByB2V5JJouJFirMGJC2Ii//saWjwLGAA/U1jJAywwmHso4SD5XhVNq3UUkERp4C4Wjh0fBCSpEUMx1UeFE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714632338; c=relaxed/simple; bh=9gpF1ZeoIB+BLVk+0MjpqZda1gRKi8C0YBM1991aFCU=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=HNVmIJ/GSS2GJzcjeEP88D8f48gpBQF/2Pkic1F6uSrFArd6yQ1bhg701SqxX6bcH8UOqsGW5da/W4HKRCLlJ989JsJ5xdCrVMLsT0Hh54RE7CpzlbmZ6flqp39AY5RJfw5osXB8mi5peYRx1AFqGnvbz7wQWz05uQqeBbn7fbw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=suse.de; spf=pass smtp.mailfrom=suse.de; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b=Uy/zHLG2; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b=SuhAbAfh; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b=Uy/zHLG2; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b=SuhAbAfh; arc=none smtp.client-ip=195.135.223.131 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=suse.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=suse.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b="Uy/zHLG2"; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b="SuhAbAfh"; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b="Uy/zHLG2"; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b="SuhAbAfh" Received: from imap1.dmz-prg2.suse.org (imap1.dmz-prg2.suse.org [IPv6:2a07:de40:b281:104:10:150:64:97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id A4E9D1FC06; Thu, 2 May 2024 06:45:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1714632334; 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=FQcMKXJVOG43VIEs3AdXElWrHRr8HzHo02RLuW651HI=; b=Uy/zHLG2qINwM71ZkxpdSs5rB3wliqrVvc1KK+lGFygIJ6bD6K9LFuBPeFT3HQE6qlM9BU nHQL2ToiCdtY9T7bqRqtFIfysKdFCIMxumLkMGiWJg+FB5mnPDt6ZRhe+yqvvCwq3yBltl 6eUE1JoyKx9dPRiqlJ2Z1BtaJDMzu4A= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1714632334; 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=FQcMKXJVOG43VIEs3AdXElWrHRr8HzHo02RLuW651HI=; b=SuhAbAfhJLl0zdsTJNbNVwymkuA2Mf2XzVBlqrzX9VgWe6WHuzdLU4l1scgPX3gzxIIFLP lV4lhnelLeU+4aCw== Authentication-Results: smtp-out2.suse.de; dkim=pass header.d=suse.de header.s=susede2_rsa header.b="Uy/zHLG2"; dkim=pass header.d=suse.de header.s=susede2_ed25519 header.b=SuhAbAfh DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1714632334; 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=FQcMKXJVOG43VIEs3AdXElWrHRr8HzHo02RLuW651HI=; b=Uy/zHLG2qINwM71ZkxpdSs5rB3wliqrVvc1KK+lGFygIJ6bD6K9LFuBPeFT3HQE6qlM9BU nHQL2ToiCdtY9T7bqRqtFIfysKdFCIMxumLkMGiWJg+FB5mnPDt6ZRhe+yqvvCwq3yBltl 6eUE1JoyKx9dPRiqlJ2Z1BtaJDMzu4A= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1714632334; 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=FQcMKXJVOG43VIEs3AdXElWrHRr8HzHo02RLuW651HI=; b=SuhAbAfhJLl0zdsTJNbNVwymkuA2Mf2XzVBlqrzX9VgWe6WHuzdLU4l1scgPX3gzxIIFLP lV4lhnelLeU+4aCw== Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id 3A4D81386E; Thu, 2 May 2024 06:45:34 +0000 (UTC) Received: from dovecot-director2.suse.de ([10.150.64.162]) by imap1.dmz-prg2.suse.org with ESMTPSA id P8XrC442M2ZuQAAAD6G6ig (envelope-from ); Thu, 02 May 2024 06:45:34 +0000 Message-ID: <317ce09b-5fec-4ed2-b32c-d098767956d0@suse.de> Date: Thu, 2 May 2024 08:45:33 +0200 Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2] block : add larger order folio size instead of pages Content-Language: en-US To: Kundan Kumar , axboe@kernel.dk, hch@lst.de, willy@infradead.org Cc: linux-block@vger.kernel.org, joshi.k@samsung.com, mcgrof@kernel.org, anuj20.g@samsung.com, nj.shetty@samsung.com, c.gameti@samsung.com, gost.dev@samsung.com References: <20240430175014.8276-1-kundan.kumar@samsung.com> From: Hannes Reinecke In-Reply-To: <20240430175014.8276-1-kundan.kumar@samsung.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Spam-Flag: NO X-Spam-Score: -4.50 X-Rspamd-Action: no action X-Rspamd-Queue-Id: A4E9D1FC06 X-Spam-Level: X-Rspamd-Server: rspamd2.dmz-prg2.suse.org X-Spamd-Result: default: False [-4.50 / 50.00]; BAYES_HAM(-3.00)[100.00%]; NEURAL_HAM_LONG(-1.00)[-1.000]; NEURAL_HAM_SHORT(-0.20)[-1.000]; R_DKIM_ALLOW(-0.20)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; MIME_GOOD(-0.10)[text/plain]; XM_UA_NO_VERSION(0.01)[]; MX_GOOD(-0.01)[]; RCPT_COUNT_SEVEN(0.00)[11]; RCVD_TLS_ALL(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; ARC_NA(0.00)[]; FUZZY_BLOCKED(0.00)[rspamd.com]; MIME_TRACE(0.00)[0:+]; MID_RHS_MATCH_FROM(0.00)[]; DKIM_SIGNED(0.00)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; DNSWL_BLOCKED(0.00)[2a07:de40:b281:104:10:150:64:97:from]; FROM_HAS_DN(0.00)[]; TO_DN_SOME(0.00)[]; FROM_EQ_ENVFROM(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; RCVD_COUNT_TWO(0.00)[2]; DKIM_TRACE(0.00)[suse.de:+] On 4/30/24 19:50, Kundan Kumar wrote: > When mTHP is enabled, IO can contain larger folios instead of pages. > In such cases add a larger size to the bio instead of looping through > pages. This reduces the overhead of iterating through pages for larger > block sizes. perf diff before and after this change: > > Perf diff for write I/O with 128K block size: > 1.26% -1.04% [kernel.kallsyms] [k] bio_iov_iter_get_pages > 1.74% [kernel.kallsyms] [k] bvec_try_merge_page > Perf diff for read I/O with 128K block size: > 4.40% -3.63% [kernel.kallsyms] [k] bio_iov_iter_get_pages > 5.60% [kernel.kallsyms] [k] bvec_try_merge_page > > Signed-off-by: Kundan Kumar > --- > Changes since v1: > https://lore.kernel.org/all/20240419091721.1790-1-kundan.kumar@samsung.com/ > - Changed functions bio_iov_add_page() and bio_iov_add_zone_append_page() to > accept a folio > - Removed branching and now calculate folio_offset and len in same fashion for > both 0 order and larger folios > - Added change in NVMe driver to use nvme_setup_prp_simple() by ignoring > multiples of NVME_CTRL_PAGE_SIZE in offset > - Added change to unpin_user_pages which were added as folios. Also stopped > the unpin of pages one by one from __bio_release_pages()(Suggested by > Keith) > > block/bio.c | 48 +++++++++++++++++++++++++---------------- > drivers/nvme/host/pci.c | 3 ++- > 2 files changed, 31 insertions(+), 20 deletions(-) > > diff --git a/block/bio.c b/block/bio.c > index 38baedb39c6f..0ec453ad15b3 100644 > --- a/block/bio.c > +++ b/block/bio.c > @@ -1155,7 +1155,6 @@ void __bio_release_pages(struct bio *bio, bool mark_dirty) > > bio_for_each_folio_all(fi, bio) { > struct page *page; > - size_t nr_pages; > > if (mark_dirty) { > folio_lock(fi.folio); > @@ -1163,11 +1162,7 @@ void __bio_release_pages(struct bio *bio, bool mark_dirty) > folio_unlock(fi.folio); > } > page = folio_page(fi.folio, fi.offset / PAGE_SIZE); > - nr_pages = (fi.offset + fi.length - 1) / PAGE_SIZE - > - fi.offset / PAGE_SIZE + 1; > - do { > - bio_release_page(bio, page++); > - } while (--nr_pages != 0); > + bio_release_page(bio, page); Errm. I guess you need to call 'folio_put()' here, otherwise the page reference counting will be messed up. > } > } > EXPORT_SYMBOL_GPL(__bio_release_pages); > @@ -1192,7 +1187,7 @@ void bio_iov_bvec_set(struct bio *bio, struct iov_iter *iter) > bio_set_flag(bio, BIO_CLONED); > } > > -static int bio_iov_add_page(struct bio *bio, struct page *page, > +static int bio_iov_add_folio(struct bio *bio, struct folio *folio, > unsigned int len, unsigned int offset) > { > bool same_page = false; > @@ -1202,27 +1197,26 @@ static int bio_iov_add_page(struct bio *bio, struct page *page, > > if (bio->bi_vcnt > 0 && > bvec_try_merge_page(&bio->bi_io_vec[bio->bi_vcnt - 1], > - page, len, offset, &same_page)) { > + &folio->page, len, offset, &same_page)) { > bio->bi_iter.bi_size += len; > if (same_page) > - bio_release_page(bio, page); > + bio_release_page(bio, &folio->page); > return 0; > } > - __bio_add_page(bio, page, len, offset); > + bio_add_folio_nofail(bio, folio, len, offset); > return 0; > } That is not a valid conversion. bvec_try_to_merge_pages() will try to merge a page with an existing bvec. If the logic is switch to folios you would need to iterate over all pages in a folio, and call bvec_try_to_merge_pages() for each page in the folio. Or convert / add a function 'bvec_try_to_merge_folio()'. But with the above patch it will only ever try to merge the first page in the folio. > > -static int bio_iov_add_zone_append_page(struct bio *bio, struct page *page, > +static int bio_iov_add_zone_append_folio(struct bio *bio, struct folio *folio, > unsigned int len, unsigned int offset) > { > struct request_queue *q = bdev_get_queue(bio->bi_bdev); > bool same_page = false; > - > - if (bio_add_hw_page(q, bio, page, len, offset, > + if (bio_add_hw_page(q, bio, &folio->page, len, offset, > queue_max_zone_append_sectors(q), &same_page) != len) Wouldn't this just try to add the first page in a folio? > return -EINVAL; > if (same_page) > - bio_release_page(bio, page); > + bio_release_page(bio, &folio->page); > return 0; > } > > @@ -1247,8 +1241,10 @@ static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter) > struct page **pages = (struct page **)bv; > ssize_t size, left; > unsigned len, i = 0; > - size_t offset; > + size_t offset, folio_offset, size_folio; > int ret = 0; > + int num_pages; > + struct folio *folio; > > /* > * Move page array up in the allocated memory for the bio vecs as far as > @@ -1289,16 +1285,30 @@ static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter) > > for (left = size, i = 0; left > 0; left -= len, i++) { > struct page *page = pages[i]; > + folio = page_folio(page); > + > + /* See the offset in folio and the size */ > + folio_offset = (folio_page_idx(folio, page) > + << PAGE_SHIFT) + offset; > + size_folio = folio_size(folio); > + > + /* Calculate the length of folio to be added */ > + len = min_t(size_t, (size_folio - folio_offset), left); > + > + num_pages = DIV_ROUND_UP(offset + len, PAGE_SIZE); > > - len = min_t(size_t, PAGE_SIZE - offset, left); > if (bio_op(bio) == REQ_OP_ZONE_APPEND) { > - ret = bio_iov_add_zone_append_page(bio, page, len, > - offset); > + ret = bio_iov_add_zone_append_folio(bio, folio, len, > + folio_offset); > if (ret) > break; > } else > - bio_iov_add_page(bio, page, len, offset); > + bio_iov_add_folio(bio, folio, len, folio_offset); > > + /* Skip the pages which got added */ > + if (bio_flagged(bio, BIO_PAGE_PINNED) && num_pages > 1) > + unpin_user_pages(pages + i, num_pages - 1); > + i = i + (num_pages - 1); > offset = 0; > } > I would rather use folio as an argument here ... > diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c > index 8e0bb9692685..7c07b0582cae 100644 > --- a/drivers/nvme/host/pci.c > +++ b/drivers/nvme/host/pci.c > @@ -778,7 +778,8 @@ static blk_status_t nvme_map_data(struct nvme_dev *dev, struct request *req, > struct bio_vec bv = req_bvec(req); > > if (!is_pci_p2pdma_page(bv.bv_page)) { > - if (bv.bv_offset + bv.bv_len <= NVME_CTRL_PAGE_SIZE * 2) > + if ((bv.bv_offset & (NVME_CTRL_PAGE_SIZE - 1)) > + + bv.bv_len <= NVME_CTRL_PAGE_SIZE * 2) > return nvme_setup_prp_simple(dev, req, > &cmnd->rw, &bv); > In general I'm in favour of moving the block layer over to folios, but then we should do it by adding a folio-based version of the functions, and the gradually convert the callers over to those functions. Trying to slide it in via folio->page or page_folio() things is not the way to do it as they are not equivalent transformations. Cheers, Hannes -- Dr. Hannes Reinecke Kernel Storage Architect hare@suse.de +49 911 74053 688 SUSE Software Solutions GmbH, Frankenstr. 146, 90461 Nürnberg HRB 36809 (AG Nürnberg), GF: I. Totev, A. McDonald, W. Knoblich