From: Nayna Jain <nayna@linux.vnet.ibm.com> To: tpmdd-devel@lists.sourceforge.net Cc: peterhuewe@gmx.de, tpmdd@selhorst.net, jarkko.sakkinen@linux.intel.com, jgunthorpe@obsidianresearch.com, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, linux-ima-devel@lists.sourceforge.net, patrickc@us.ibm.com, Nayna Jain <nayna@linux.vnet.ibm.com> Subject: [PATCH v2 3/4] tpm: reduce tpm_msleep() time in get_burstcount() Date: Wed, 6 Sep 2017 08:56:38 -0400 [thread overview] Message-ID: <20170906125643.5070-4-nayna@linux.vnet.ibm.com> (raw) In-Reply-To: <20170906125643.5070-1-nayna@linux.vnet.ibm.com> Currently, get_burstcount() function sleeps for 5msec in a loop before retrying for next query to burstcount. However, if it takes lesser time for TPM to return, this 5 msec delay is longer than necessary. This patch replaces the tpm_msleep time from 5msec to 1msec. After this change, performance on a TPM 1.2 with an 8 byte burstcount for 1000 extends improved from ~10sec to ~9sec. Signed-off-by: Nayna Jain <nayna@linux.vnet.ibm.com> Acked-by: Mimi Zohar <zohar@linux.vnet.ibm.com> --- drivers/char/tpm/tpm_tis_core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c index d1eab29cb447..d710bbc4608b 100644 --- a/drivers/char/tpm/tpm_tis_core.c +++ b/drivers/char/tpm/tpm_tis_core.c @@ -169,7 +169,7 @@ static int get_burstcount(struct tpm_chip *chip) burstcnt = (value >> 8) & 0xFFFF; if (burstcnt) return burstcnt; - tpm_msleep(TPM_TIMEOUT); + tpm_msleep(1); } while (time_before(jiffies, stop)); return -EBUSY; } -- 2.13.3
next prev parent reply other threads:[~2017-09-06 12:56 UTC|newest] Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top 2017-09-06 12:56 [PATCH v2 0/4] additional TPM performance improvements Nayna Jain 2017-09-06 12:56 ` Nayna Jain [this message] 2017-09-13 1:00 ` [PATCH v2 3/4] tpm: reduce tpm_msleep() time in get_burstcount() Jarkko Sakkinen 2017-09-15 12:40 ` Nayna Jain [not found] ` <20170906125643.5070-1-nayna-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org> 2017-09-06 12:56 ` [PATCH v2 1/4] tpm: ignore burstcount to improve tpm_tis send() performance Nayna Jain 2017-09-06 16:12 ` Jason Gunthorpe 2017-09-13 18:52 ` [tpmdd-devel] " Ken Goldman [not found] ` <3c418974-a4c7-518e-b218-f6373c10209e-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org> 2017-09-13 19:01 ` Peter Huewe 2017-09-13 0:45 ` Jarkko Sakkinen [not found] ` <20170912222010.ltm76m5vy2kupydi-VuQAYsv1563Yd54FQh9/CA@public.gmane.org> 2017-09-13 18:39 ` Peter Huewe 2017-09-13 23:10 ` Jarkko Sakkinen 2017-09-15 12:29 ` Nayna Jain 2017-09-15 15:19 ` Jarkko Sakkinen 2017-09-06 12:56 ` [PATCH v2 2/4] tpm: define __wait_for_tpm_stat to specify variable polling sleep time Nayna Jain 2017-09-13 0:58 ` Jarkko Sakkinen 2017-09-15 12:37 ` Nayna Jain 2017-09-15 15:20 ` Jarkko Sakkinen 2017-09-06 12:56 ` [PATCH v2 4/4] tpm: use tpm_msleep() value as max delay Nayna Jain 2017-09-13 0:47 ` Jarkko Sakkinen 2017-09-14 9:25 ` Nayna Jain 2017-09-14 12:28 ` Jarkko Sakkinen 2017-09-06 12:56 ` [PATCH 2/4] tpm: define __wait_for_tpm_stat to specify variable polling sleep time Nayna Jain 2017-09-06 12:58 ` Nayna 2017-09-06 12:56 ` [PATCH 1/4] tpm: ignore burstcount to improve tpm_tis send() performance Nayna Jain [not found] ` <20170906125643.5070-6-nayna-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org> 2017-09-06 12:58 ` Nayna 2017-09-07 16:18 ` [PATCH v2 0/4] additional TPM performance improvements Jarkko Sakkinen 2017-09-11 15:20 ` [tpmdd-devel] " Alexander.Steffen
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