Re: [PATCH] irqbalance, powerpc: add IRQs without settable SMP affinity to banned list
size_t size =3D 0; FILE *file; sprintf(buf, /proc/irq/%i/smp_affinity, number); - file =3D fopen(buf, r); + file =3D fopen(buf, r+); if (!file) continue; if (getline(line, size, file)=3D=3D0) { @@ -89,7 +89,14 @@ continue; } cpumask_parse_user(line, strlen(line), irq-mask); - fclose(file); + /* + * Check that we can write the affinity, if + * not take it out of the list. + */ + if (fputs(line, file) =3D=3D EOF) + can_set =3D 0; This is maybe a nit, but writing to the affinity file can fail for a few different reasons, some of them permanent, some transient. For instance,= if we're in a memory constrained condition temporarily irq_affinity_proc_wri= te might return -ENOMEM. =20 Yeah true, usually followed shortly by your kernel going so far into swap you never get it back, or OOMing, but I guess it's possible. Might it be better to modify this code so that, instead of using fputs to merge the various errors into an EOF, we use some other= write method that lets us better determine the error and selectively ban the in= terrupt only for those errors which we consider permanent? Yep. It seems fputs() gives you know way to get the actual error from write(), so it looks we'll need to switch to open/write, but that's probably not so terrible. fclose inherits the error from fputs and it sets errno correctly. Below uses this to catch only EIO errors and mark them for the banned list. Mikey irqbalance, powerpc: add IRQs without settable SMP affinity to banned list On pseries powerpc, IPIs are registered with an IRQ number so /proc/interrupts looks like this on a 2 core/2 thread machine: CPU0 CPU1 CPU2 CPU3 16:316428232905141138794 983121 XICS Level IPI 18:2605674 0 304994 0 XICS Level lan0 30: 400057 0 169209 0 XICS Level ibmvscsi LOC: 133734 77250 106425 91951 Local timer interrupts SPU: 0 0 0 0 Spurious interrupts CNT: 0 0 0 0 Performance monitoring interrupts MCE: 0 0 0 0 Machine check exceptions Unfortunately this means irqbalance attempts to set the affinity of IPIs which is not possible. So in the above case, when irqbalance is in performance mode due to heavy IPI, lan0 and ibmvscsi activity, it sometimes attempts to put the IPIs on one core (CPU01) and lan0 and ibmvscsi on the other core (CPU23). This is suboptimal as we want lan0 and ibmvscsi to be on separate cores and IPIs to be ignored. When irqblance attempts writes to the IPI smp_affinity (ie. /proc/irq/16/smp_affinity in the above example) it fails with an EIO but irqbalance currently ignores this. This patch catches these write fails and in this case adds that IRQ number to the banned IRQ list. This will catch the above IPI case and any other IRQ where the SMP affinity can't be set. Tested on POWER6, POWER7 and x86. Signed-off-by: Michael Neuling mi...@neuling.org Index: irqbalance/irqlist.c === --- irqbalance.orig/irqlist.c +++ irqbalance/irqlist.c @@ -28,6 +28,7 @@ #include unistd.h #include sys/types.h #include dirent.h +#include errno.h #include types.h #include irqbalance.h @@ -67,7 +68,7 @@ DIR *dir; struct dirent *entry; char *c, *c2; - int nr , count = 0; + int nr , count = 0, can_set = 1; char buf[PATH_MAX]; sprintf(buf, /proc/irq/%i, number); dir = opendir(buf); @@ -80,7 +81,7 @@ size_t size = 0; FILE *file; sprintf(buf, /proc/irq/%i/smp_affinity, number); - file = fopen(buf, r); + file = fopen(buf, r+); if (!file) continue; if (getline(line, size, file)==0) { @@ -89,7 +90,13 @@ continue; } cpumask_parse_user(line, strlen(line), irq-mask); - fclose(file); + /* +* Check that we can write the affinity, if +* not take it out of the list. +*/ + fputs(line, file); + if (fclose(file) errno == EIO) + can_set = 0;
Re: [PATCH] irqbalance, powerpc: add IRQs without settable SMP affinity to banned list
On Fri, Sep 24, 2010 at 04:56:34PM +1000, Michael Neuling wrote: size_t size =3D 0; FILE *file; sprintf(buf, /proc/irq/%i/smp_affinity, number); - file =3D fopen(buf, r); + file =3D fopen(buf, r+); if (!file) continue; if (getline(line, size, file)=3D=3D0) { @@ -89,7 +89,14 @@ continue; } cpumask_parse_user(line, strlen(line), irq-mask); - fclose(file); + /* +* Check that we can write the affinity, if +* not take it out of the list. +*/ + if (fputs(line, file) =3D=3D EOF) + can_set =3D 0; This is maybe a nit, but writing to the affinity file can fail for a few different reasons, some of them permanent, some transient. For instance,= if we're in a memory constrained condition temporarily irq_affinity_proc_wri= te might return -ENOMEM. =20 Yeah true, usually followed shortly by your kernel going so far into swap you never get it back, or OOMing, but I guess it's possible. Might it be better to modify this code so that, instead of using fputs to merge the various errors into an EOF, we use some other= write method that lets us better determine the error and selectively ban the in= terrupt only for those errors which we consider permanent? Yep. It seems fputs() gives you know way to get the actual error from write(), so it looks we'll need to switch to open/write, but that's probably not so terrible. fclose inherits the error from fputs and it sets errno correctly. Below uses this to catch only EIO errors and mark them for the banned list. Mikey irqbalance, powerpc: add IRQs without settable SMP affinity to banned list On pseries powerpc, IPIs are registered with an IRQ number so /proc/interrupts looks like this on a 2 core/2 thread machine: CPU0 CPU1 CPU2 CPU3 16:316428232905141138794 983121 XICS Level IPI 18:2605674 0 304994 0 XICS Level lan0 30: 400057 0 169209 0 XICS Level ibmvscsi LOC: 133734 77250 106425 91951 Local timer interrupts SPU: 0 0 0 0 Spurious interrupts CNT: 0 0 0 0 Performance monitoring interrupts MCE: 0 0 0 0 Machine check exceptions Unfortunately this means irqbalance attempts to set the affinity of IPIs which is not possible. So in the above case, when irqbalance is in performance mode due to heavy IPI, lan0 and ibmvscsi activity, it sometimes attempts to put the IPIs on one core (CPU01) and lan0 and ibmvscsi on the other core (CPU23). This is suboptimal as we want lan0 and ibmvscsi to be on separate cores and IPIs to be ignored. When irqblance attempts writes to the IPI smp_affinity (ie. /proc/irq/16/smp_affinity in the above example) it fails with an EIO but irqbalance currently ignores this. This patch catches these write fails and in this case adds that IRQ number to the banned IRQ list. This will catch the above IPI case and any other IRQ where the SMP affinity can't be set. Tested on POWER6, POWER7 and x86. Signed-off-by: Michael Neuling mi...@neuling.org Index: irqbalance/irqlist.c === --- irqbalance.orig/irqlist.c +++ irqbalance/irqlist.c @@ -28,6 +28,7 @@ #include unistd.h #include sys/types.h #include dirent.h +#include errno.h #include types.h #include irqbalance.h @@ -67,7 +68,7 @@ DIR *dir; struct dirent *entry; char *c, *c2; - int nr , count = 0; + int nr , count = 0, can_set = 1; char buf[PATH_MAX]; sprintf(buf, /proc/irq/%i, number); dir = opendir(buf); @@ -80,7 +81,7 @@ size_t size = 0; FILE *file; sprintf(buf, /proc/irq/%i/smp_affinity, number); - file = fopen(buf, r); + file = fopen(buf, r+); if (!file) continue; if (getline(line, size, file)==0) { @@ -89,7 +90,13 @@ continue; } cpumask_parse_user(line, strlen(line), irq-mask); - fclose(file); + /* + * Check that we can write the
Re: [PATCH] irqbalance, powerpc: add IRQs without settable SMP affinity to banned list
On Wed, 2010-09-22 at 16:04 +1000, Michael Neuling wrote: When irqblance attempts writes to the IPI smp_affinity (ie. /proc/irq/16/smp_affinity in the above example) it fails but irqbalance ignores currently ignores this. This patch catches these write fails and in this case adds that IRQ number to the banned IRQ list. This will catch the above IPI case and any other IRQ where the SMP affinity can't be set. Cool! Index: irqbalance/irqlist.c === --- irqbalance.orig/irqlist.c +++ irqbalance/irqlist.c @@ -67,7 +67,7 @@ DIR *dir; struct dirent *entry; char *c, *c2; - int nr , count = 0; + int nr , count = 0, can_set = 1; char buf[PATH_MAX]; sprintf(buf, /proc/irq/%i, number); dir = opendir(buf); @@ -80,7 +80,7 @@ size_t size = 0; FILE *file; sprintf(buf, /proc/irq/%i/smp_affinity, number); - file = fopen(buf, r); + file = fopen(buf, r+); if (!file) continue; if (getline(line, size, file)==0) { @@ -89,7 +89,14 @@ continue; } cpumask_parse_user(line, strlen(line), irq-mask); - fclose(file); + /* + * Check that we can write the affinity, if + * not take it out of the list. + */ + if (fwrite(line, strlen(line) - 1, 1, file) == 0) if (fputs(line, file) == EOF) ? cheers signature.asc Description: This is a digitally signed message part ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
Re: [PATCH] irqbalance, powerpc: add IRQs without settable SMP affinity to banned list
+ if (fwrite(line, strlen(line) - 1, 1, file) == 0) if (fputs(line, file) == EOF) Good point thanks... new patch below Mikey irqbalance, powerpc: add IRQs without settable SMP affinity to banned list On pseries powerpc, IPIs are registered with an IRQ number so /proc/interrupts looks like this on a 2 core/2 thread machine: CPU0 CPU1 CPU2 CPU3 16:316428232905141138794 983121 XICS Level IPI 18:2605674 0 304994 0 XICS Level lan0 30: 400057 0 169209 0 XICS Level ibmvscsi LOC: 133734 77250 106425 91951 Local timer interrupts SPU: 0 0 0 0 Spurious interrupts CNT: 0 0 0 0 Performance monitoring interrupts MCE: 0 0 0 0 Machine check exceptions Unfortunately this means irqbalance attempts to set the affinity of IPIs which is not possible. So in the above case, when irqbalance is in performance mode due to heavy IPI, lan0 and ibmvscsi activity, it sometimes attempts to put the IPIs on one core (CPU01) and lan0 and ibmvscsi on the other core (CPU23). This is suboptimal as we want lan0 and ibmvscsi to be on separate cores and IPIs to be ignored. When irqblance attempts writes to the IPI smp_affinity (ie. /proc/irq/16/smp_affinity in the above example) it fails but irqbalance ignores currently ignores this. This patch catches these write fails and in this case adds that IRQ number to the banned IRQ list. This will catch the above IPI case and any other IRQ where the SMP affinity can't be set. Tested on POWER6, POWER7 and x86. Signed-off-by: Michael Neuling mi...@neuling.org Index: irqbalance/irqlist.c === --- irqbalance.orig/irqlist.c +++ irqbalance/irqlist.c @@ -67,7 +67,7 @@ DIR *dir; struct dirent *entry; char *c, *c2; - int nr , count = 0; + int nr , count = 0, can_set = 1; char buf[PATH_MAX]; sprintf(buf, /proc/irq/%i, number); dir = opendir(buf); @@ -80,7 +80,7 @@ size_t size = 0; FILE *file; sprintf(buf, /proc/irq/%i/smp_affinity, number); - file = fopen(buf, r); + file = fopen(buf, r+); if (!file) continue; if (getline(line, size, file)==0) { @@ -89,7 +89,14 @@ continue; } cpumask_parse_user(line, strlen(line), irq-mask); - fclose(file); + /* +* Check that we can write the affinity, if +* not take it out of the list. +*/ + if (fputs(line, file) == EOF) + can_set = 0; + if (fclose(file)) + can_set = 0; free(line); } else if (strcmp(entry-d_name,allowed_affinity)==0) { char *line = NULL; @@ -122,7 +129,7 @@ count++; /* if there is no choice in the allowed mask, don't bother to balance */ - if (count2) + if ((count2) || (can_set == 0)) irq-balance_level = BALANCE_NONE; ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
Re: [PATCH] irqbalance, powerpc: add IRQs without settable SMP affinity to banned list
On Thu, Sep 23, 2010 at 08:57:20PM +1000, Michael Neuling wrote: + if (fwrite(line, strlen(line) - 1, 1, file) == 0) if (fputs(line, file) == EOF) Good point thanks... new patch below Mikey irqbalance, powerpc: add IRQs without settable SMP affinity to banned list On pseries powerpc, IPIs are registered with an IRQ number so /proc/interrupts looks like this on a 2 core/2 thread machine: CPU0 CPU1 CPU2 CPU3 16:316428232905141138794 983121 XICS Level IPI 18:2605674 0 304994 0 XICS Level lan0 30: 400057 0 169209 0 XICS Level ibmvscsi LOC: 133734 77250 106425 91951 Local timer interrupts SPU: 0 0 0 0 Spurious interrupts CNT: 0 0 0 0 Performance monitoring interrupts MCE: 0 0 0 0 Machine check exceptions Unfortunately this means irqbalance attempts to set the affinity of IPIs which is not possible. So in the above case, when irqbalance is in performance mode due to heavy IPI, lan0 and ibmvscsi activity, it sometimes attempts to put the IPIs on one core (CPU01) and lan0 and ibmvscsi on the other core (CPU23). This is suboptimal as we want lan0 and ibmvscsi to be on separate cores and IPIs to be ignored. When irqblance attempts writes to the IPI smp_affinity (ie. /proc/irq/16/smp_affinity in the above example) it fails but irqbalance ignores currently ignores this. This patch catches these write fails and in this case adds that IRQ number to the banned IRQ list. This will catch the above IPI case and any other IRQ where the SMP affinity can't be set. Tested on POWER6, POWER7 and x86. Signed-off-by: Michael Neuling mi...@neuling.org Index: irqbalance/irqlist.c === --- irqbalance.orig/irqlist.c +++ irqbalance/irqlist.c @@ -67,7 +67,7 @@ DIR *dir; struct dirent *entry; char *c, *c2; - int nr , count = 0; + int nr , count = 0, can_set = 1; char buf[PATH_MAX]; sprintf(buf, /proc/irq/%i, number); dir = opendir(buf); @@ -80,7 +80,7 @@ size_t size = 0; FILE *file; sprintf(buf, /proc/irq/%i/smp_affinity, number); - file = fopen(buf, r); + file = fopen(buf, r+); if (!file) continue; if (getline(line, size, file)==0) { @@ -89,7 +89,14 @@ continue; } cpumask_parse_user(line, strlen(line), irq-mask); - fclose(file); + /* + * Check that we can write the affinity, if + * not take it out of the list. + */ + if (fputs(line, file) == EOF) + can_set = 0; This is maybe a nit, but writing to the affinity file can fail for a few different reasons, some of them permanent, some transient. For instance, if we're in a memory constrained condition temporarily irq_affinity_proc_write might return -ENOMEM. Might it be better to modify this code so that, instead of using fputs to merge the various errors into an EOF, we use some other write method that lets us better determine the error and selectively ban the interrupt only for those errors which we consider permanent? Otherwise this looks fine to me. Thanks Neil ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
Re: [PATCH] irqbalance, powerpc: add IRQs without settable SMP affinity to banned list
On Thu, 2010-09-23 at 09:13 -0400, Neil Horman wrote: On Thu, Sep 23, 2010 at 08:57:20PM +1000, Michael Neuling wrote: + if (fwrite(line, strlen(line) - 1, 1, file) == 0) if (fputs(line, file) == EOF) Good point thanks... new patch below Mikey irqbalance, powerpc: add IRQs without settable SMP affinity to banned list On pseries powerpc, IPIs are registered with an IRQ number so /proc/interrupts looks like this on a 2 core/2 thread machine: CPU0 CPU1 CPU2 CPU3 16:316428232905141138794 983121 XICS Level IPI 18:2605674 0 304994 0 XICS Level lan0 30: 400057 0 169209 0 XICS Level ibmvscsi LOC: 133734 77250 106425 91951 Local timer interrupts SPU: 0 0 0 0 Spurious interrupts CNT: 0 0 0 0 Performance monitoring interrupts MCE: 0 0 0 0 Machine check exceptions Unfortunately this means irqbalance attempts to set the affinity of IPIs which is not possible. So in the above case, when irqbalance is in performance mode due to heavy IPI, lan0 and ibmvscsi activity, it sometimes attempts to put the IPIs on one core (CPU01) and lan0 and ibmvscsi on the other core (CPU23). This is suboptimal as we want lan0 and ibmvscsi to be on separate cores and IPIs to be ignored. When irqblance attempts writes to the IPI smp_affinity (ie. /proc/irq/16/smp_affinity in the above example) it fails but irqbalance ignores currently ignores this. This patch catches these write fails and in this case adds that IRQ number to the banned IRQ list. This will catch the above IPI case and any other IRQ where the SMP affinity can't be set. Tested on POWER6, POWER7 and x86. Signed-off-by: Michael Neuling mi...@neuling.org Index: irqbalance/irqlist.c === --- irqbalance.orig/irqlist.c +++ irqbalance/irqlist.c @@ -67,7 +67,7 @@ DIR *dir; struct dirent *entry; char *c, *c2; - int nr , count = 0; + int nr , count = 0, can_set = 1; char buf[PATH_MAX]; sprintf(buf, /proc/irq/%i, number); dir = opendir(buf); @@ -80,7 +80,7 @@ size_t size = 0; FILE *file; sprintf(buf, /proc/irq/%i/smp_affinity, number); - file = fopen(buf, r); + file = fopen(buf, r+); if (!file) continue; if (getline(line, size, file)==0) { @@ -89,7 +89,14 @@ continue; } cpumask_parse_user(line, strlen(line), irq-mask); - fclose(file); + /* +* Check that we can write the affinity, if +* not take it out of the list. +*/ + if (fputs(line, file) == EOF) + can_set = 0; This is maybe a nit, but writing to the affinity file can fail for a few different reasons, some of them permanent, some transient. For instance, if we're in a memory constrained condition temporarily irq_affinity_proc_write might return -ENOMEM. Yeah true, usually followed shortly by your kernel going so far into swap you never get it back, or OOMing, but I guess it's possible. Might it be better to modify this code so that, instead of using fputs to merge the various errors into an EOF, we use some other write method that lets us better determine the error and selectively ban the interrupt only for those errors which we consider permanent? Yep. It seems fputs() gives you know way to get the actual error from write(), so it looks we'll need to switch to open/write, but that's probably not so terrible. cheers signature.asc Description: This is a digitally signed message part ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
[PATCH] irqbalance, powerpc: add IRQs without settable SMP affinity to banned list
On pseries powerpc, IPIs are registered with an IRQ number so /proc/interrupts looks like this on a 2 core/2 thread machine: CPU0 CPU1 CPU2 CPU3 16:316428232905141138794 983121 XICS Level IPI 18:2605674 0 304994 0 XICS Level lan0 30: 400057 0 169209 0 XICS Level ibmvscsi LOC: 133734 77250 106425 91951 Local timer interrupts SPU: 0 0 0 0 Spurious interrupts CNT: 0 0 0 0 Performance monitoring interrupts MCE: 0 0 0 0 Machine check exceptions Unfortunately this means irqbalance attempts to set the affinity of IPIs which is not possible. So in the above case, when irqbalance is in performance mode due to heavy IPI, lan0 and ibmvscsi activity, it sometimes attempts to put the IPIs on one core (CPU01) and lan0 and ibmvscsi on the other core (CPU23). This is suboptimal as we want lan0 and ibmvscsi to be on separate cores and IPIs to be ignored. When irqblance attempts writes to the IPI smp_affinity (ie. /proc/irq/16/smp_affinity in the above example) it fails but irqbalance ignores currently ignores this. This patch catches these write fails and in this case adds that IRQ number to the banned IRQ list. This will catch the above IPI case and any other IRQ where the SMP affinity can't be set. Tested on POWER6, POWER7 and x86. Signed-off-by: Michael Neuling mi...@neuling.org Index: irqbalance/irqlist.c === --- irqbalance.orig/irqlist.c +++ irqbalance/irqlist.c @@ -67,7 +67,7 @@ DIR *dir; struct dirent *entry; char *c, *c2; - int nr , count = 0; + int nr , count = 0, can_set = 1; char buf[PATH_MAX]; sprintf(buf, /proc/irq/%i, number); dir = opendir(buf); @@ -80,7 +80,7 @@ size_t size = 0; FILE *file; sprintf(buf, /proc/irq/%i/smp_affinity, number); - file = fopen(buf, r); + file = fopen(buf, r+); if (!file) continue; if (getline(line, size, file)==0) { @@ -89,7 +89,14 @@ continue; } cpumask_parse_user(line, strlen(line), irq-mask); - fclose(file); + /* +* Check that we can write the affinity, if +* not take it out of the list. +*/ + if (fwrite(line, strlen(line) - 1, 1, file) == 0) + can_set = 0; + if (fclose(file)) + can_set = 0; free(line); } else if (strcmp(entry-d_name,allowed_affinity)==0) { char *line = NULL; @@ -122,7 +129,7 @@ count++; /* if there is no choice in the allowed mask, don't bother to balance */ - if (count2) + if ((count2) || (can_set == 0)) irq-balance_level = BALANCE_NONE; ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev