July 2019 - Linux-stable-mirror

[PATCH 4.14, 4.19, 5.1] mm: vmscan: scan anonymous pages on file refaults

by Kuo-Hsin Yang

commit 2c012a4ad1a2cd3fb5a0f9307b9d219f84eda1fa upstream. When file refaults are detected and there are many inactive file pages, the system never reclaim anonymous pages, the file pages are dropped aggressively when there are still a lot of cold anonymous pages and system thrashes. This issue impacts the performance of applications with large executable, e.g. chrome. With this patch, when file refault is detected, inactive_list_is_low() always returns true for file pages in get_scan_count() to enable scanning anonymous pages. The problem can be reproduced by the following test program. ---8<--- void fallocate_file(const char *filename, off_t size) { struct stat st; int fd; if (!stat(filename, &st) && st.st_size >= size) return; fd = open(filename, O_WRONLY | O_CREAT, 0600); if (fd < 0) { perror("create file"); exit(1); } if (posix_fallocate(fd, 0, size)) { perror("fallocate"); exit(1); } close(fd); } long *alloc_anon(long size) { long *start = malloc(size); memset(start, 1, size); return start; } long access_file(const char *filename, long size, long rounds) { int fd, i; volatile char *start1, *end1, *start2; const int page_size = getpagesize(); long sum = 0; fd = open(filename, O_RDONLY); if (fd == -1) { perror("open"); exit(1); } /* * Some applications, e.g. chrome, use a lot of executable file * pages, map some of the pages with PROT_EXEC flag to simulate * the behavior. */ start1 = mmap(NULL, size / 2, PROT_READ | PROT_EXEC, MAP_SHARED, fd, 0); if (start1 == MAP_FAILED) { perror("mmap"); exit(1); } end1 = start1 + size / 2; start2 = mmap(NULL, size / 2, PROT_READ, MAP_SHARED, fd, size / 2); if (start2 == MAP_FAILED) { perror("mmap"); exit(1); } for (i = 0; i < rounds; ++i) { struct timeval before, after; volatile char *ptr1 = start1, *ptr2 = start2; gettimeofday(&before, NULL); for (; ptr1 < end1; ptr1 += page_size, ptr2 += page_size) sum += *ptr1 + *ptr2; gettimeofday(&after, NULL); printf("File access time, round %d: %f (sec) ", i, (after.tv_sec - before.tv_sec) + (after.tv_usec - before.tv_usec) / 1000000.0); } return sum; } int main(int argc, char *argv[]) { const long MB = 1024 * 1024; long anon_mb, file_mb, file_rounds; const char filename[] = "large"; long *ret1; long ret2; if (argc != 4) { printf("usage: thrash ANON_MB FILE_MB FILE_ROUNDS "); exit(0); } anon_mb = atoi(argv[1]); file_mb = atoi(argv[2]); file_rounds = atoi(argv[3]); fallocate_file(filename, file_mb * MB); printf("Allocate %ld MB anonymous pages ", anon_mb); ret1 = alloc_anon(anon_mb * MB); printf("Access %ld MB file pages ", file_mb); ret2 = access_file(filename, file_mb * MB, file_rounds); printf("Print result to prevent optimization: %ld ", *ret1 + ret2); return 0; } ---8<--- Running the test program on 2GB RAM VM with kernel 5.2.0-rc5, the program fills ram with 2048 MB memory, access a 200 MB file for 10 times. Without this patch, the file cache is dropped aggresively and every access to the file is from disk. $ ./thrash 2048 200 10 Allocate 2048 MB anonymous pages Access 200 MB file pages File access time, round 0: 2.489316 (sec) File access time, round 1: 2.581277 (sec) File access time, round 2: 2.487624 (sec) File access time, round 3: 2.449100 (sec) File access time, round 4: 2.420423 (sec) File access time, round 5: 2.343411 (sec) File access time, round 6: 2.454833 (sec) File access time, round 7: 2.483398 (sec) File access time, round 8: 2.572701 (sec) File access time, round 9: 2.493014 (sec) With this patch, these file pages can be cached. $ ./thrash 2048 200 10 Allocate 2048 MB anonymous pages Access 200 MB file pages File access time, round 0: 2.475189 (sec) File access time, round 1: 2.440777 (sec) File access time, round 2: 2.411671 (sec) File access time, round 3: 1.955267 (sec) File access time, round 4: 0.029924 (sec) File access time, round 5: 0.000808 (sec) File access time, round 6: 0.000771 (sec) File access time, round 7: 0.000746 (sec) File access time, round 8: 0.000738 (sec) File access time, round 9: 0.000747 (sec) Checked the swap out stats during the test [1], 19006 pages swapped out with this patch, 3418 pages swapped out without this patch. There are more swap out, but I think it's within reasonable range when file backed data set doesn't fit into the memory. $ ./thrash 2000 100 2100 5 1 # ANON_MB FILE_EXEC FILE_NOEXEC ROUNDS PROCESSES Allocate 2000 MB anonymous pages active_anon: 1613644, inactive_anon: 348656, active_file: 892, inactive_file: 1384 (kB) pswpout: 7972443, pgpgin: 478615246 Access 100 MB executable file pages Access 2100 MB regular file pages File access time, round 0: 12.165, (sec) active_anon: 1433788, inactive_anon: 478116, active_file: 17896, inactive_file: 24328 (kB) File access time, round 1: 11.493, (sec) active_anon: 1430576, inactive_anon: 477144, active_file: 25440, inactive_file: 26172 (kB) File access time, round 2: 11.455, (sec) active_anon: 1427436, inactive_anon: 476060, active_file: 21112, inactive_file: 28808 (kB) File access time, round 3: 11.454, (sec) active_anon: 1420444, inactive_anon: 473632, active_file: 23216, inactive_file: 35036 (kB) File access time, round 4: 11.479, (sec) active_anon: 1413964, inactive_anon: 471460, active_file: 31728, inactive_file: 32224 (kB) pswpout: 7991449 (+ 19006), pgpgin: 489924366 (+ 11309120) With 4 processes accessing non-overlapping parts of a large file, 30316 pages swapped out with this patch, 5152 pages swapped out without this patch. The swapout number is small comparing to pgpgin. [1]: https://github.com/vovo/testing/blob/master/mem_thrash.c Link: http://lkml.kernel.org/r/20190701081038.GA83398@google.com Fixes: e9868505987a ("mm,vmscan: only evict file pages when we have plenty") Fixes: 7c5bd705d8f9 ("mm: memcg: only evict file pages when we have plenty") Signed-off-by: Kuo-Hsin Yang <vovoy(a)chromium.org> Acked-by: Johannes Weiner <hannes(a)cmpxchg.org> Cc: Michal Hocko <mhocko(a)suse.com> Cc: Sonny Rao <sonnyrao(a)chromium.org> Cc: Mel Gorman <mgorman(a)techsingularity.net> Cc: Rik van Riel <riel(a)redhat.com> Cc: Vladimir Davydov <vdavydov.dev(a)gmail.com> Cc: Minchan Kim <minchan(a)kernel.org> Cc: <stable(a)vger.kernel.org> [4.12+] Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds(a)linux-foundation.org> [backported to 4.14.y, 4.19.y, 5.1.y: adjust context] Signed-off-by: Kuo-Hsin Yang <vovoy(a)chromium.org> --- mm/vmscan.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 290078e8d4b1d..0cc3c1eb15f5a 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -2120,7 +2120,7 @@ static void shrink_active_list(unsigned long nr_to_scan, * 10TB 320 32GB */ static bool inactive_list_is_low(struct lruvec *lruvec, bool file, - struct scan_control *sc, bool actual_reclaim) + struct scan_control *sc, bool trace) { enum lru_list active_lru = file * LRU_FILE + LRU_ACTIVE; struct pglist_data *pgdat = lruvec_pgdat(lruvec); @@ -2146,7 +2146,7 @@ static bool inactive_list_is_low(struct lruvec *lruvec, bool file, * rid of the stale workingset quickly. */ refaults = lruvec_page_state(lruvec, WORKINGSET_ACTIVATE); - if (file && actual_reclaim && lruvec->refaults != refaults) { + if (file && lruvec->refaults != refaults) { inactive_ratio = 0; } else { gb = (inactive + active) >> (30 - PAGE_SHIFT); @@ -2156,7 +2156,7 @@ static bool inactive_list_is_low(struct lruvec *lruvec, bool file, inactive_ratio = 1; } - if (actual_reclaim) + if (trace) trace_mm_vmscan_inactive_list_is_low(pgdat->node_id, sc->reclaim_idx, lruvec_lru_size(lruvec, inactive_lru, MAX_NR_ZONES), inactive, lruvec_lru_size(lruvec, active_lru, MAX_NR_ZONES), active, -- 2.22.0.709.g102302147b-goog

5 years, 2 months

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[PATCH stable-5.1 0/3] KVM: x86: FPU and nested VMX guest reset fixes

by Vitaly Kuznetsov

Few patches were recently marked for stable@ but commits are not backportable as-is and require a few tweaks. Here is 5.1 stable backport. [PATCH2 of the series applies as-is, I have it here for completeness] Jan Kiszka (1): KVM: nVMX: Clear pending KVM_REQ_GET_VMCS12_PAGES when leaving nested Paolo Bonzini (2): KVM: nVMX: do not use dangling shadow VMCS after guest reset Revert "kvm: x86: Use task structs fpu field for user" arch/x86/include/asm/kvm_host.h | 7 ++++--- arch/x86/kvm/vmx/nested.c | 10 +++++++++- arch/x86/kvm/x86.c | 4 ++-- 3 files changed, 15 insertions(+), 6 deletions(-) -- 2.20.1

5 years, 2 months

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[PATCH stable-5.2 0/3] KVM: x86: FPU and nested VMX guest reset fixes

by Vitaly Kuznetsov

Few patches were recently marked for stable@ but commits are not backportable as-is and require a few tweaks. Here is 5.2 stable backport. [PATCHes 2/3 of the series apply as-is, I have them here for completeness] Jan Kiszka (1): KVM: nVMX: Clear pending KVM_REQ_GET_VMCS12_PAGES when leaving nested Paolo Bonzini (2): KVM: nVMX: do not use dangling shadow VMCS after guest reset Revert "kvm: x86: Use task structs fpu field for user" arch/x86/include/asm/kvm_host.h | 7 ++++--- arch/x86/kvm/vmx/nested.c | 10 +++++++++- arch/x86/kvm/x86.c | 4 ++-- 3 files changed, 15 insertions(+), 6 deletions(-) -- 2.20.1

5 years, 2 months

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[PATCH AUTOSEL 5.2 01/85] ARM: riscpc: fix DMA

by Sasha Levin

From: Russell King <rmk+kernel(a)armlinux.org.uk> [ Upstream commit ffd9a1ba9fdb7f2bd1d1ad9b9243d34e96756ba2 ] DMA got broken a while back in two different ways: 1) a change in the behaviour of disable_irq() to wait for the interrupt to finish executing causes us to deadlock at the end of DMA. 2) a change to avoid modifying the scatterlist left the first transfer uninitialised. DMA is only used with expansion cards, so has gone unnoticed. Fixes: fa4e99899932 ("[ARM] dma: RiscPC: don't modify DMA SG entries") Signed-off-by: Russell King <rmk+kernel(a)armlinux.org.uk> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- arch/arm/mach-rpc/dma.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/arm/mach-rpc/dma.c b/arch/arm/mach-rpc/dma.c index 488d5c3b37f4..799e0b016b62 100644 --- a/arch/arm/mach-rpc/dma.c +++ b/arch/arm/mach-rpc/dma.c @@ -128,7 +128,7 @@ static irqreturn_t iomd_dma_handle(int irq, void *dev_id) } while (1); idma->state = ~DMA_ST_AB; - disable_irq(irq); + disable_irq_nosync(irq); return IRQ_HANDLED; } @@ -177,6 +177,9 @@ static void iomd_enable_dma(unsigned int chan, dma_t *dma) DMA_FROM_DEVICE : DMA_TO_DEVICE); } + idma->dma_addr = idma->dma.sg->dma_address; + idma->dma_len = idma->dma.sg->length; + iomd_writeb(DMA_CR_C, dma_base + CR); idma->state = DMA_ST_AB; } -- 2.20.1

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[PATCH AUTOSEL 4.4 01/23] ARM: riscpc: fix DMA

by Sasha Levin

From: Russell King <rmk+kernel(a)armlinux.org.uk> [ Upstream commit ffd9a1ba9fdb7f2bd1d1ad9b9243d34e96756ba2 ] DMA got broken a while back in two different ways: 1) a change in the behaviour of disable_irq() to wait for the interrupt to finish executing causes us to deadlock at the end of DMA. 2) a change to avoid modifying the scatterlist left the first transfer uninitialised. DMA is only used with expansion cards, so has gone unnoticed. Fixes: fa4e99899932 ("[ARM] dma: RiscPC: don't modify DMA SG entries") Signed-off-by: Russell King <rmk+kernel(a)armlinux.org.uk> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- arch/arm/mach-rpc/dma.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/arm/mach-rpc/dma.c b/arch/arm/mach-rpc/dma.c index 6d3517dc4772..82aac38fa2cf 100644 --- a/arch/arm/mach-rpc/dma.c +++ b/arch/arm/mach-rpc/dma.c @@ -131,7 +131,7 @@ static irqreturn_t iomd_dma_handle(int irq, void *dev_id) } while (1); idma->state = ~DMA_ST_AB; - disable_irq(irq); + disable_irq_nosync(irq); return IRQ_HANDLED; } @@ -174,6 +174,9 @@ static void iomd_enable_dma(unsigned int chan, dma_t *dma) DMA_FROM_DEVICE : DMA_TO_DEVICE); } + idma->dma_addr = idma->dma.sg->dma_address; + idma->dma_len = idma->dma.sg->length; + iomd_writeb(DMA_CR_C, dma_base + CR); idma->state = DMA_ST_AB; } -- 2.20.1

5 years, 2 months

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[PATCH AUTOSEL 4.9 01/30] ARM: riscpc: fix DMA

by Sasha Levin

From: Russell King <rmk+kernel(a)armlinux.org.uk> [ Upstream commit ffd9a1ba9fdb7f2bd1d1ad9b9243d34e96756ba2 ] DMA got broken a while back in two different ways: 1) a change in the behaviour of disable_irq() to wait for the interrupt to finish executing causes us to deadlock at the end of DMA. 2) a change to avoid modifying the scatterlist left the first transfer uninitialised. DMA is only used with expansion cards, so has gone unnoticed. Fixes: fa4e99899932 ("[ARM] dma: RiscPC: don't modify DMA SG entries") Signed-off-by: Russell King <rmk+kernel(a)armlinux.org.uk> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- arch/arm/mach-rpc/dma.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/arm/mach-rpc/dma.c b/arch/arm/mach-rpc/dma.c index 6d3517dc4772..82aac38fa2cf 100644 --- a/arch/arm/mach-rpc/dma.c +++ b/arch/arm/mach-rpc/dma.c @@ -131,7 +131,7 @@ static irqreturn_t iomd_dma_handle(int irq, void *dev_id) } while (1); idma->state = ~DMA_ST_AB; - disable_irq(irq); + disable_irq_nosync(irq); return IRQ_HANDLED; } @@ -174,6 +174,9 @@ static void iomd_enable_dma(unsigned int chan, dma_t *dma) DMA_FROM_DEVICE : DMA_TO_DEVICE); } + idma->dma_addr = idma->dma.sg->dma_address; + idma->dma_len = idma->dma.sg->length; + iomd_writeb(DMA_CR_C, dma_base + CR); idma->state = DMA_ST_AB; } -- 2.20.1

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[PATCH AUTOSEL 4.14 01/37] ARM: riscpc: fix DMA

by Sasha Levin

From: Russell King <rmk+kernel(a)armlinux.org.uk> [ Upstream commit ffd9a1ba9fdb7f2bd1d1ad9b9243d34e96756ba2 ] DMA got broken a while back in two different ways: 1) a change in the behaviour of disable_irq() to wait for the interrupt to finish executing causes us to deadlock at the end of DMA. 2) a change to avoid modifying the scatterlist left the first transfer uninitialised. DMA is only used with expansion cards, so has gone unnoticed. Fixes: fa4e99899932 ("[ARM] dma: RiscPC: don't modify DMA SG entries") Signed-off-by: Russell King <rmk+kernel(a)armlinux.org.uk> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- arch/arm/mach-rpc/dma.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/arm/mach-rpc/dma.c b/arch/arm/mach-rpc/dma.c index fb48f3141fb4..c4c96661eb89 100644 --- a/arch/arm/mach-rpc/dma.c +++ b/arch/arm/mach-rpc/dma.c @@ -131,7 +131,7 @@ static irqreturn_t iomd_dma_handle(int irq, void *dev_id) } while (1); idma->state = ~DMA_ST_AB; - disable_irq(irq); + disable_irq_nosync(irq); return IRQ_HANDLED; } @@ -174,6 +174,9 @@ static void iomd_enable_dma(unsigned int chan, dma_t *dma) DMA_FROM_DEVICE : DMA_TO_DEVICE); } + idma->dma_addr = idma->dma.sg->dma_address; + idma->dma_len = idma->dma.sg->length; + iomd_writeb(DMA_CR_C, dma_base + CR); idma->state = DMA_ST_AB; } -- 2.20.1

5 years, 2 months

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[PATCH AUTOSEL 4.19 01/47] ARM: riscpc: fix DMA

by Sasha Levin

From: Russell King <rmk+kernel(a)armlinux.org.uk> [ Upstream commit ffd9a1ba9fdb7f2bd1d1ad9b9243d34e96756ba2 ] DMA got broken a while back in two different ways: 1) a change in the behaviour of disable_irq() to wait for the interrupt to finish executing causes us to deadlock at the end of DMA. 2) a change to avoid modifying the scatterlist left the first transfer uninitialised. DMA is only used with expansion cards, so has gone unnoticed. Fixes: fa4e99899932 ("[ARM] dma: RiscPC: don't modify DMA SG entries") Signed-off-by: Russell King <rmk+kernel(a)armlinux.org.uk> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- arch/arm/mach-rpc/dma.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/arm/mach-rpc/dma.c b/arch/arm/mach-rpc/dma.c index fb48f3141fb4..c4c96661eb89 100644 --- a/arch/arm/mach-rpc/dma.c +++ b/arch/arm/mach-rpc/dma.c @@ -131,7 +131,7 @@ static irqreturn_t iomd_dma_handle(int irq, void *dev_id) } while (1); idma->state = ~DMA_ST_AB; - disable_irq(irq); + disable_irq_nosync(irq); return IRQ_HANDLED; } @@ -174,6 +174,9 @@ static void iomd_enable_dma(unsigned int chan, dma_t *dma) DMA_FROM_DEVICE : DMA_TO_DEVICE); } + idma->dma_addr = idma->dma.sg->dma_address; + idma->dma_len = idma->dma.sg->length; + iomd_writeb(DMA_CR_C, dma_base + CR); idma->state = DMA_ST_AB; } -- 2.20.1

5 years, 2 months

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FAILED: patch "[PATCH] net: stmmac: Re-work the queue selection for TSO packets" failed to apply to 4.14-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.14-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 4993e5b37e8bcb55ac90f76eb6d2432647273747 Mon Sep 17 00:00:00 2001 From: Jose Abreu <Jose.Abreu(a)synopsys.com> Date: Mon, 8 Jul 2019 14:26:28 +0200 Subject: [PATCH] net: stmmac: Re-work the queue selection for TSO packets Ben Hutchings says: "This is the wrong place to change the queue mapping. stmmac_xmit() is called with a specific TX queue locked, and accessing a different TX queue results in a data race for all of that queue's state. I think this commit should be reverted upstream and in all stable branches. Instead, the driver should implement the ndo_select_queue operation and override the queue mapping there." Fixes: c5acdbee22a1 ("net: stmmac: Send TSO packets always from Queue 0") Suggested-by: Ben Hutchings <ben(a)decadent.org.uk> Signed-off-by: Jose Abreu <joabreu(a)synopsys.com> Signed-off-by: David S. Miller <davem(a)davemloft.net> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c index 06358fe5b245..11b6feb33b54 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c @@ -3045,17 +3045,8 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev) /* Manage oversized TCP frames for GMAC4 device */ if (skb_is_gso(skb) && priv->tso) { - if (skb_shinfo(skb)->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6)) { - /* - * There is no way to determine the number of TSO - * capable Queues. Let's use always the Queue 0 - * because if TSO is supported then at least this - * one will be capable. - */ - skb_set_queue_mapping(skb, 0); - + if (skb_shinfo(skb)->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6)) return stmmac_tso_xmit(skb, dev); - } } if (unlikely(stmmac_tx_avail(priv, queue) < nfrags + 1)) { @@ -3872,6 +3863,22 @@ static int stmmac_setup_tc(struct net_device *ndev, enum tc_setup_type type, } } +static u16 stmmac_select_queue(struct net_device *dev, struct sk_buff *skb, + struct net_device *sb_dev) +{ + if (skb_shinfo(skb)->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6)) { + /* + * There is no way to determine the number of TSO + * capable Queues. Let's use always the Queue 0 + * because if TSO is supported then at least this + * one will be capable. + */ + return 0; + } + + return netdev_pick_tx(dev, skb, NULL) % dev->real_num_tx_queues; +} + static int stmmac_set_mac_address(struct net_device *ndev, void *addr) { struct stmmac_priv *priv = netdev_priv(ndev); @@ -4088,6 +4095,7 @@ static const struct net_device_ops stmmac_netdev_ops = { .ndo_tx_timeout = stmmac_tx_timeout, .ndo_do_ioctl = stmmac_ioctl, .ndo_setup_tc = stmmac_setup_tc, + .ndo_select_queue = stmmac_select_queue, #ifdef CONFIG_NET_POLL_CONTROLLER .ndo_poll_controller = stmmac_poll_controller, #endif

5 years, 2 months

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[PATCH 1/3] arm64: perf: Mark expected switch fall-through

by Anders Roxell

When fall-through warnings was enabled by default, commit d93512ef0f0e ("Makefile: Globally enable fall-through warning"), the following warnings was starting to show up: ../arch/arm64/kernel/hw_breakpoint.c: In function ‘hw_breakpoint_arch_parse’: ../arch/arm64/kernel/hw_breakpoint.c:540:7: warning: this statement may fall through [-Wimplicit-fallthrough=] if (hw->ctrl.len == ARM_BREAKPOINT_LEN_1) ^ ../arch/arm64/kernel/hw_breakpoint.c:542:3: note: here case 2: ^~~~ ../arch/arm64/kernel/hw_breakpoint.c:544:7: warning: this statement may fall through [-Wimplicit-fallthrough=] if (hw->ctrl.len == ARM_BREAKPOINT_LEN_2) ^ ../arch/arm64/kernel/hw_breakpoint.c:546:3: note: here default: ^~~~~~~ Rework so that the compiler doesn't warn about fall-through. Rework so the code looks like the arm code. Since the comment in the function indicates taht this is supposed to behave the same way as arm32 because it handles 32-bit tasks also. Cc: stable(a)vger.kernel.org # v3.16+ Fixes: 6ee33c2712fc ("ARM: hw_breakpoint: correct and simplify alignment fixup code") Signed-off-by: Anders Roxell <anders.roxell(a)linaro.org> --- arch/arm64/kernel/hw_breakpoint.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/arch/arm64/kernel/hw_breakpoint.c b/arch/arm64/kernel/hw_breakpoint.c index dceb84520948..ea616adf1cf1 100644 --- a/arch/arm64/kernel/hw_breakpoint.c +++ b/arch/arm64/kernel/hw_breakpoint.c @@ -535,14 +535,17 @@ int hw_breakpoint_arch_parse(struct perf_event *bp, case 0: /* Aligned */ break; - case 1: - /* Allow single byte watchpoint. */ - if (hw->ctrl.len == ARM_BREAKPOINT_LEN_1) - break; case 2: /* Allow halfword watchpoints and breakpoints. */ if (hw->ctrl.len == ARM_BREAKPOINT_LEN_2) break; + /* Fall through */ + case 1: + case 3: + /* Allow single byte watchpoint. */ + if (hw->ctrl.len == ARM_BREAKPOINT_LEN_1) + break; + /* Fall through */ default: return -EINVAL; } -- 2.20.1

5 years, 2 months

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