From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gabriel Krisman Bertazi Subject: Re: [PATCH] bnx2x: Alloc 4k fragment for each rx ring buffer element Date: Wed, 27 May 2015 13:51:43 -0300 Message-ID: <87vbfeoteo.fsf_-_@sycorax.br.ibm.com> References: <553AD097.4020209@gmx.de> <87383jhxj9.fsf@dhcp-9-18-235-171.br.ibm.com> <20150430.160537.232956261880122754.davem@davemloft.net> <874mnsxhnm.fsf_-_@dhcp-9-18-235-171.br.ibm.com> <87wq02t6ce.fsf_-_@dhcp-9-18-235-171.br.ibm.com> <55658781.8060104@redhat.com> Mime-Version: 1.0 Content-Type: text/plain Cc: Yuval Mintz , David Miller , "LinoSanfilippo\@gmx.de" , Ariel Elior , netdev , "cascardo\@cascardo.eti.br" , "brking\@linux.vnet.ibm.com" To: Michal Schmidt Return-path: Received: from e24smtp03.br.ibm.com ([32.104.18.24]:55710 "EHLO e24smtp03.br.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752159AbbE0Qvv (ORCPT ); Wed, 27 May 2015 12:51:51 -0400 Received: from /spool/local by e24smtp03.br.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 27 May 2015 13:51:49 -0300 Received: from d24relay01.br.ibm.com (d24relay01.br.ibm.com [9.8.31.16]) by d24dlp02.br.ibm.com (Postfix) with ESMTP id 6D26A1DC0070 for ; Wed, 27 May 2015 12:50:45 -0400 (EDT) Received: from d24av01.br.ibm.com (d24av01.br.ibm.com [9.8.31.91]) by d24relay01.br.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id t4RGq4N45193790 for ; Wed, 27 May 2015 13:52:05 -0300 Received: from d24av01.br.ibm.com (localhost [127.0.0.1]) by d24av01.br.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id t4RGphnD021955 for ; Wed, 27 May 2015 13:51:44 -0300 In-Reply-To: <55658781.8060104@redhat.com> (Michal Schmidt's message of "Wed, 27 May 2015 10:59:45 +0200") Sender: netdev-owner@vger.kernel.org List-ID: Michal Schmidt writes: > One SGE_PAGE_SIZE is already bigger than representable by u8, so offset > will overflow. Ouch, this bug was introduced in the last iteration, sorry. Fixed. > Isn't storing both 'offset' and 'frag_count' redundant? There is a > simple linear relationship between the two. Yes, but I felt it would make the code more readable, even though it introduced sobre redundancy. Anyway, the new version below removes frag_count and fixes the overflow bug. Thanks for your review! -- >8 -- Subject: [PATCH] bnx2x: Alloc 4k fragment for each rx ring buffer element The driver allocates one page for each buffer on the rx ring, which is too much on architectures like ppc64 and can cause unexpected allocation failures when the system is under stress. Now, we keep a memory pool per queue, and if the architecture's PAGE_SIZE is greater than 4k, we fragment pages and assign each 4k segment to a ring element, which reduces the overall memory consumption on such architectures. This helps avoiding errors like the example below: [bnx2x_alloc_rx_sge:435(eth1)]Can't alloc sge [c00000037ffeb900] [d000000075eddeb4] .bnx2x_alloc_rx_sge+0x44/0x200 [bnx2x] [c00000037ffeb9b0] [d000000075ee0b34] .bnx2x_fill_frag_skb+0x1ac/0x460 [bnx2x] [c00000037ffebac0] [d000000075ee11f0] .bnx2x_tpa_stop+0x160/0x2e8 [bnx2x] [c00000037ffebb90] [d000000075ee1560] .bnx2x_rx_int+0x1e8/0xc30 [bnx2x] [c00000037ffebcd0] [d000000075ee2084] .bnx2x_poll+0xdc/0x3d8 [bnx2x] (unreliable) Signed-off-by: Gabriel Krisman Bertazi Acked-by: Yuval Mintz Reviewed-by: Lino Sanfilippo --- drivers/net/ethernet/broadcom/bnx2x/bnx2x.h | 16 +++++-- drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c | 57 +++++++++++++++++-------- drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.h | 31 ++++++++++++-- 3 files changed, 80 insertions(+), 24 deletions(-) diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x.h b/drivers/net/ethernet/broadcom/bnx2x/bnx2x.h index 4085c4b..d127b9a 100644 --- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x.h +++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x.h @@ -357,6 +357,7 @@ struct sw_tx_bd { struct sw_rx_page { struct page *page; DEFINE_DMA_UNMAP_ADDR(mapping); + unsigned int offset; }; union db_prod { @@ -381,9 +382,10 @@ union db_prod { #define PAGES_PER_SGE_SHIFT 0 #define PAGES_PER_SGE (1 << PAGES_PER_SGE_SHIFT) -#define SGE_PAGE_SIZE PAGE_SIZE -#define SGE_PAGE_SHIFT PAGE_SHIFT -#define SGE_PAGE_ALIGN(addr) PAGE_ALIGN((typeof(PAGE_SIZE))(addr)) +#define SGE_PAGE_SHIFT 12 +#define SGE_PAGE_SIZE (1 << SGE_PAGE_SHIFT) +#define SGE_PAGE_MASK (~(SGE_PAGE_SIZE - 1)) +#define SGE_PAGE_ALIGN(addr) (((addr) + SGE_PAGE_SIZE - 1) & SGE_PAGE_MASK) #define SGE_PAGES (SGE_PAGE_SIZE * PAGES_PER_SGE) #define TPA_AGG_SIZE min_t(u32, (min_t(u32, 8, MAX_SKB_FRAGS) * \ SGE_PAGES), 0xffff) @@ -525,6 +527,12 @@ enum bnx2x_tpa_mode_t { TPA_MODE_GRO }; +struct bnx2x_alloc_pool { + struct page *page; + dma_addr_t dma; + unsigned int offset; +}; + struct bnx2x_fastpath { struct bnx2x *bp; /* parent */ @@ -611,6 +619,8 @@ struct bnx2x_fastpath { 4 (for the digits and to make it DWORD aligned) */ #define FP_NAME_SIZE (sizeof(((struct net_device *)0)->name) + 8) char name[FP_NAME_SIZE]; + + struct bnx2x_alloc_pool page_pool; }; #define bnx2x_fp(bp, nr, var) ((bp)->fp[(nr)].var) diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c index 0a9faa1..70dea69 100644 --- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c +++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c @@ -544,30 +544,49 @@ static void bnx2x_set_gro_params(struct sk_buff *skb, u16 parsing_flags, static int bnx2x_alloc_rx_sge(struct bnx2x *bp, struct bnx2x_fastpath *fp, u16 index, gfp_t gfp_mask) { - struct page *page = alloc_pages(gfp_mask, PAGES_PER_SGE_SHIFT); struct sw_rx_page *sw_buf = &fp->rx_page_ring[index]; struct eth_rx_sge *sge = &fp->rx_sge_ring[index]; + struct bnx2x_alloc_pool *pool = &fp->page_pool; dma_addr_t mapping; - if (unlikely(page == NULL)) { - BNX2X_ERR("Can't alloc sge\n"); - return -ENOMEM; - } + if (!pool->page || (PAGE_SIZE - pool->offset) < SGE_PAGE_SIZE) { - mapping = dma_map_page(&bp->pdev->dev, page, 0, - SGE_PAGES, DMA_FROM_DEVICE); - if (unlikely(dma_mapping_error(&bp->pdev->dev, mapping))) { - __free_pages(page, PAGES_PER_SGE_SHIFT); - BNX2X_ERR("Can't map sge\n"); - return -ENOMEM; + /* put page reference used by the memory pool, since we + * won't be using this page as the mempool anymore. + */ + if (pool->page) + put_page(pool->page); + + pool->page = alloc_pages(gfp_mask, PAGES_PER_SGE_SHIFT); + if (unlikely(!pool->page)) { + BNX2X_ERR("Can't alloc sge\n"); + return -ENOMEM; + } + + pool->dma = dma_map_page(&bp->pdev->dev, pool->page, 0, + PAGE_SIZE, DMA_FROM_DEVICE); + if (unlikely(dma_mapping_error(&bp->pdev->dev, + pool->dma))) { + __free_pages(pool->page, PAGES_PER_SGE_SHIFT); + pool->page = NULL; + BNX2X_ERR("Can't map sge\n"); + return -ENOMEM; + } + pool->offset = 0; } - sw_buf->page = page; + get_page(pool->page); + sw_buf->page = pool->page; + sw_buf->offset = pool->offset; + + mapping = pool->dma + sw_buf->offset; dma_unmap_addr_set(sw_buf, mapping, mapping); sge->addr_hi = cpu_to_le32(U64_HI(mapping)); sge->addr_lo = cpu_to_le32(U64_LO(mapping)); + pool->offset += SGE_PAGE_SIZE; + return 0; } @@ -629,20 +648,22 @@ static int bnx2x_fill_frag_skb(struct bnx2x *bp, struct bnx2x_fastpath *fp, return err; } - /* Unmap the page as we're going to pass it to the stack */ - dma_unmap_page(&bp->pdev->dev, - dma_unmap_addr(&old_rx_pg, mapping), - SGE_PAGES, DMA_FROM_DEVICE); + dma_unmap_single(&bp->pdev->dev, + dma_unmap_addr(&old_rx_pg, mapping), + SGE_PAGE_SIZE, DMA_FROM_DEVICE); /* Add one frag and update the appropriate fields in the skb */ if (fp->mode == TPA_MODE_LRO) - skb_fill_page_desc(skb, j, old_rx_pg.page, 0, frag_len); + skb_fill_page_desc(skb, j, old_rx_pg.page, + old_rx_pg.offset, frag_len); else { /* GRO */ int rem; int offset = 0; for (rem = frag_len; rem > 0; rem -= gro_size) { int len = rem > gro_size ? gro_size : rem; skb_fill_page_desc(skb, frag_id++, - old_rx_pg.page, offset, len); + old_rx_pg.page, + old_rx_pg.offset + offset, + len); if (offset) get_page(old_rx_pg.page); offset += len; diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.h b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.h index adcacda..1df9d78 100644 --- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.h +++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.h @@ -804,9 +804,13 @@ static inline void bnx2x_free_rx_sge(struct bnx2x *bp, if (!page) return; - dma_unmap_page(&bp->pdev->dev, dma_unmap_addr(sw_buf, mapping), - SGE_PAGES, DMA_FROM_DEVICE); - __free_pages(page, PAGES_PER_SGE_SHIFT); + /* Since many fragments can share the same page, make sure to + * only unmap and free the page once. + */ + dma_unmap_single(&bp->pdev->dev, dma_unmap_addr(sw_buf, mapping), + SGE_PAGE_SIZE, DMA_FROM_DEVICE); + + put_page(page); sw_buf->page = NULL; sge->addr_hi = 0; @@ -964,6 +968,25 @@ static inline void bnx2x_set_fw_mac_addr(__le16 *fw_hi, __le16 *fw_mid, ((u8 *)fw_lo)[1] = mac[4]; } +static inline void bnx2x_free_rx_mem_pool(struct bnx2x *bp, + struct bnx2x_alloc_pool *pool) +{ + if (!pool->page) + return; + + /* Page was not fully fragmented. Unmap unused space */ + if (pool->offset < PAGE_SIZE) { + dma_addr_t dma = pool->dma + pool->offset; + int size = PAGE_SIZE - pool->offset; + + dma_unmap_single(&bp->pdev->dev, dma, size, DMA_FROM_DEVICE); + } + + put_page(pool->page); + + pool->page = NULL; +} + static inline void bnx2x_free_rx_sge_range(struct bnx2x *bp, struct bnx2x_fastpath *fp, int last) { @@ -974,6 +997,8 @@ static inline void bnx2x_free_rx_sge_range(struct bnx2x *bp, for (i = 0; i < last; i++) bnx2x_free_rx_sge(bp, fp, i); + + bnx2x_free_rx_mem_pool(bp, &fp->page_pool); } static inline void bnx2x_set_next_page_rx_bd(struct bnx2x_fastpath *fp) -- 2.1.0