From: Dan Williams <dan.j.williams@intel.com> To: stable@vger.kernel.org Cc: Erwin Tsaur <erwin.tsaur@oracle.com>, linux-nvdimm@lists.01.org Subject: [4.19, 5.0 stable PATCH 3/4] nfit/ars: Allow root to busy-poll the ARS state machine Date: Mon, 22 Apr 2019 16:08:21 -0700 [thread overview] Message-ID: <155597450168.2675082.12797199567190628607.stgit@dwillia2-desk3.amr.corp.intel.com> (raw) In-Reply-To: <155597449036.2675082.7035380482732870260.stgit@dwillia2-desk3.amr.corp.intel.com> commit 5479b2757f26fe9908fc341d105b2097fe820b6f upstream. The ARS implementation implements exponential back-off on the poll interval to prevent high-frequency access to the DIMM / platform interface. Depending on when the ARS completes the poll interval may exceed the completion event by minutes. Allow root to reset the timeout each time it probes the status. A one-second timeout is still enforced, but root can otherwise can control the poll interval. Fixes: bc6ba8085842 ("nfit, address-range-scrub: rework and simplify ARS...") Cc: <stable@vger.kernel.org> Reported-by: Erwin Tsaur <erwin.tsaur@oracle.com> Reviewed-by: Toshi Kani <toshi.kani@hpe.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> --- drivers/acpi/nfit/core.c | 8 ++++++++ drivers/acpi/nfit/nfit.h | 1 + 2 files changed, 9 insertions(+) diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c index 64308e669250..61d3fd65fbe9 100644 --- a/drivers/acpi/nfit/core.c +++ b/drivers/acpi/nfit/core.c @@ -1335,6 +1335,13 @@ static ssize_t scrub_show(struct device *dev, busy = test_bit(ARS_BUSY, &acpi_desc->scrub_flags) && !test_bit(ARS_CANCEL, &acpi_desc->scrub_flags); rc = sprintf(buf, "%d%s", acpi_desc->scrub_count, busy ? "+\n" : "\n"); + /* Allow an admin to poll the busy state at a higher rate */ + if (busy && capable(CAP_SYS_RAWIO) && !test_and_set_bit(ARS_POLL, + &acpi_desc->scrub_flags)) { + acpi_desc->scrub_tmo = 1; + mod_delayed_work(nfit_wq, &acpi_desc->dwork, HZ); + } + mutex_unlock(&acpi_desc->init_mutex); device_unlock(dev); return rc; @@ -3196,6 +3203,7 @@ static void acpi_nfit_scrub(struct work_struct *work) else notify_ars_done(acpi_desc); memset(acpi_desc->ars_status, 0, acpi_desc->max_ars); + clear_bit(ARS_POLL, &acpi_desc->scrub_flags); mutex_unlock(&acpi_desc->init_mutex); } diff --git a/drivers/acpi/nfit/nfit.h b/drivers/acpi/nfit/nfit.h index 897ce10192a0..d14bad687fb8 100644 --- a/drivers/acpi/nfit/nfit.h +++ b/drivers/acpi/nfit/nfit.h @@ -213,6 +213,7 @@ struct nfit_mem { enum scrub_flags { ARS_BUSY, ARS_CANCEL, + ARS_POLL, }; struct acpi_nfit_desc { _______________________________________________ Linux-nvdimm mailing list Linux-nvdimm@lists.01.org https://lists.01.org/mailman/listinfo/linux-nvdimm
WARNING: multiple messages have this Message-ID (diff)
From: Dan Williams <dan.j.williams@intel.com> To: stable@vger.kernel.org Cc: Erwin Tsaur <erwin.tsaur@oracle.com>, Toshi Kani <toshi.kani@hpe.com>, vishal.l.verma@intel.com, linux-nvdimm@lists.01.org Subject: [4.19, 5.0 stable PATCH 3/4] nfit/ars: Allow root to busy-poll the ARS state machine Date: Mon, 22 Apr 2019 16:08:21 -0700 [thread overview] Message-ID: <155597450168.2675082.12797199567190628607.stgit@dwillia2-desk3.amr.corp.intel.com> (raw) In-Reply-To: <155597449036.2675082.7035380482732870260.stgit@dwillia2-desk3.amr.corp.intel.com> commit 5479b2757f26fe9908fc341d105b2097fe820b6f upstream. The ARS implementation implements exponential back-off on the poll interval to prevent high-frequency access to the DIMM / platform interface. Depending on when the ARS completes the poll interval may exceed the completion event by minutes. Allow root to reset the timeout each time it probes the status. A one-second timeout is still enforced, but root can otherwise can control the poll interval. Fixes: bc6ba8085842 ("nfit, address-range-scrub: rework and simplify ARS...") Cc: <stable@vger.kernel.org> Reported-by: Erwin Tsaur <erwin.tsaur@oracle.com> Reviewed-by: Toshi Kani <toshi.kani@hpe.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> --- drivers/acpi/nfit/core.c | 8 ++++++++ drivers/acpi/nfit/nfit.h | 1 + 2 files changed, 9 insertions(+) diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c index 64308e669250..61d3fd65fbe9 100644 --- a/drivers/acpi/nfit/core.c +++ b/drivers/acpi/nfit/core.c @@ -1335,6 +1335,13 @@ static ssize_t scrub_show(struct device *dev, busy = test_bit(ARS_BUSY, &acpi_desc->scrub_flags) && !test_bit(ARS_CANCEL, &acpi_desc->scrub_flags); rc = sprintf(buf, "%d%s", acpi_desc->scrub_count, busy ? "+\n" : "\n"); + /* Allow an admin to poll the busy state at a higher rate */ + if (busy && capable(CAP_SYS_RAWIO) && !test_and_set_bit(ARS_POLL, + &acpi_desc->scrub_flags)) { + acpi_desc->scrub_tmo = 1; + mod_delayed_work(nfit_wq, &acpi_desc->dwork, HZ); + } + mutex_unlock(&acpi_desc->init_mutex); device_unlock(dev); return rc; @@ -3196,6 +3203,7 @@ static void acpi_nfit_scrub(struct work_struct *work) else notify_ars_done(acpi_desc); memset(acpi_desc->ars_status, 0, acpi_desc->max_ars); + clear_bit(ARS_POLL, &acpi_desc->scrub_flags); mutex_unlock(&acpi_desc->init_mutex); } diff --git a/drivers/acpi/nfit/nfit.h b/drivers/acpi/nfit/nfit.h index 897ce10192a0..d14bad687fb8 100644 --- a/drivers/acpi/nfit/nfit.h +++ b/drivers/acpi/nfit/nfit.h @@ -213,6 +213,7 @@ struct nfit_mem { enum scrub_flags { ARS_BUSY, ARS_CANCEL, + ARS_POLL, }; struct acpi_nfit_desc {
next prev parent reply other threads:[~2019-04-22 23:22 UTC|newest] Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-04-22 23:08 [4.19, 5.0 stable PATCH 1/4] nfit/ars: Remove ars_start_flags Dan Williams 2019-04-22 23:08 ` Dan Williams 2019-04-22 23:08 ` [4.19, 5.0 stable PATCH 2/4] nfit/ars: Introduce scrub_flags Dan Williams 2019-04-22 23:08 ` Dan Williams 2019-04-22 23:08 ` Dan Williams [this message] 2019-04-22 23:08 ` [4.19, 5.0 stable PATCH 3/4] nfit/ars: Allow root to busy-poll the ARS state machine Dan Williams 2019-04-22 23:08 ` [4.19, 5.0 stable PATCH 4/4] nfit/ars: Avoid stale ARS results Dan Williams 2019-04-22 23:08 ` Dan Williams 2019-04-23 13:24 ` [4.19, 5.0 stable PATCH 1/4] nfit/ars: Remove ars_start_flags Sasha Levin 2019-04-23 13:24 ` Sasha Levin
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