All of lore.kernel.org
 help / color / mirror / Atom feed
From: Nayna Jain <nayna@linux.vnet.ibm.com>
To: linux-integrity@vger.kernel.org
Cc: zohar@linux.vnet.ibm.com, linux-security-module@vger.kernel.org,
	linux-kernel@vger.kernel.org, peterhuewe@gmx.de,
	jarkko.sakkinen@linux.intel.com, tpmdd@selhorst.net,
	jgunthorpe@obsidianresearch.com, patrickc@us.ibm.com,
	Nayna Jain <nayna@linux.vnet.ibm.com>
Subject: [PATCH 2/3] tpm: reduce poll sleep time between send() and recv() in tpm_transmit()
Date: Wed, 28 Feb 2018 14:18:27 -0500	[thread overview]
Message-ID: <20180228191828.20056-2-nayna@linux.vnet.ibm.com> (raw)
In-Reply-To: <20180228191828.20056-1-nayna@linux.vnet.ibm.com>

In tpm_transmit, after send(), the code checks for status in a loop
with polling every 5msec. It is expected that the tpm might return
earlier than 5msec, so it might be adding to unnecessary delay.

This patch reduces the polling sleep time from 5msec to 1msec.

After this change, performance on a TPM 1.2 with an 8 byte
burstcount for 1000 extends improved from ~14sec to ~10.7sec.

Signed-off-by: Nayna Jain <nayna@linux.vnet.ibm.com>
---
 drivers/char/tpm/tpm-interface.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index 76df4fbcf089..2d22f981f0c9 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -470,7 +470,7 @@ ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space,
 			goto out;
 		}
 
-		tpm_msleep(TPM_TIMEOUT);
+		tpm_msleep(TPM_TIMEOUT_POLL);
 		rmb();
 	} while (time_before(jiffies, stop));
 
-- 
2.13.3

WARNING: multiple messages have this Message-ID (diff)
From: nayna@linux.vnet.ibm.com (Nayna Jain)
To: linux-security-module@vger.kernel.org
Subject: [PATCH 2/3] tpm: reduce poll sleep time between send() and recv() in tpm_transmit()
Date: Wed, 28 Feb 2018 14:18:27 -0500	[thread overview]
Message-ID: <20180228191828.20056-2-nayna@linux.vnet.ibm.com> (raw)
In-Reply-To: <20180228191828.20056-1-nayna@linux.vnet.ibm.com>

In tpm_transmit, after send(), the code checks for status in a loop
with polling every 5msec. It is expected that the tpm might return
earlier than 5msec, so it might be adding to unnecessary delay.

This patch reduces the polling sleep time from 5msec to 1msec.

After this change, performance on a TPM 1.2 with an 8 byte
burstcount for 1000 extends improved from ~14sec to ~10.7sec.

Signed-off-by: Nayna Jain <nayna@linux.vnet.ibm.com>
---
 drivers/char/tpm/tpm-interface.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index 76df4fbcf089..2d22f981f0c9 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -470,7 +470,7 @@ ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space,
 			goto out;
 		}
 
-		tpm_msleep(TPM_TIMEOUT);
+		tpm_msleep(TPM_TIMEOUT_POLL);
 		rmb();
 	} while (time_before(jiffies, stop));
 
-- 
2.13.3

--
To unsubscribe from this list: send the line "unsubscribe linux-security-module" in
the body of a message to majordomo at vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

  reply	other threads:[~2018-02-28 19:18 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-02-28 19:18 [PATCH 1/3] tpm: move TPM_POLL_SLEEP from tpm_tis_core.c to tpm.h Nayna Jain
2018-02-28 19:18 ` Nayna Jain
2018-02-28 19:18 ` Nayna Jain [this message]
2018-02-28 19:18   ` [PATCH 2/3] tpm: reduce poll sleep time between send() and recv() in tpm_transmit() Nayna Jain
2018-03-01  9:22   ` Jarkko Sakkinen
2018-03-01  9:22     ` Jarkko Sakkinen
2018-03-01 18:56     ` Nayna Jain
2018-03-01 18:56       ` Nayna Jain
2018-03-01 18:56       ` Nayna Jain
2018-03-05 10:56       ` Jarkko Sakkinen
2018-03-05 10:56         ` Jarkko Sakkinen
2018-03-05 10:56         ` Jarkko Sakkinen
2018-03-05 18:01         ` Jarkko Sakkinen
2018-03-05 18:01           ` Jarkko Sakkinen
2018-03-05 18:01           ` Jarkko Sakkinen
2018-03-05 19:07           ` Mimi Zohar
2018-03-05 19:07             ` Mimi Zohar
2018-03-05 19:07             ` Mimi Zohar
2018-03-06 11:06             ` Jarkko Sakkinen
2018-03-06 11:06               ` Jarkko Sakkinen
2018-02-28 19:18 ` [RFC PATCH 3/3] tpm: tpm_msleep() with finer granularity improves performance Nayna Jain
2018-02-28 19:18   ` Nayna Jain
2018-03-01  9:58   ` Jarkko Sakkinen
2018-03-01  9:58     ` Jarkko Sakkinen
2018-03-02  8:13     ` Nayna Jain
2018-03-02  8:13       ` Nayna Jain
2018-03-02  8:13       ` Nayna Jain
2018-03-01  8:37 ` [PATCH 1/3] tpm: move TPM_POLL_SLEEP from tpm_tis_core.c to tpm.h Jarkko Sakkinen
2018-03-01  8:37   ` Jarkko Sakkinen
2018-03-01 18:44   ` Nayna Jain
2018-03-01 18:44     ` Nayna Jain
2018-03-01 18:44     ` Nayna Jain

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20180228191828.20056-2-nayna@linux.vnet.ibm.com \
    --to=nayna@linux.vnet.ibm.com \
    --cc=jarkko.sakkinen@linux.intel.com \
    --cc=jgunthorpe@obsidianresearch.com \
    --cc=linux-integrity@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-security-module@vger.kernel.org \
    --cc=patrickc@us.ibm.com \
    --cc=peterhuewe@gmx.de \
    --cc=tpmdd@selhorst.net \
    --cc=zohar@linux.vnet.ibm.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.