mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: "Robert P. J. Day" <rpjday@mindspring.com>
To: Linux kernel mailing list <linux-kernel@vger.kernel.org>
Subject: [PATCH] Get rid of "double zeroing" of allocated pages
Date: Wed, 3 Jan 2007 10:39:29 -0500 (EST)	[thread overview]
Message-ID: <Pine.LNX.4.64.0701031033470.27478@localhost.localdomain> (raw)


  Simplify the few instances where a call to "get_zeroed_page()" is
closely followed by an unnecessary call to memset() to clear that
page.

Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>

---

  there appeared to be only three of these in the tree, and i'm not
quite sure about the instance in drivers/scsi/53c7xx.c, since that
snippet of code allocates a zeroed page, but calls memset() with a
hardcoded size of 4096.  not sure what *that's* all about, so maybe i
shouldn't be messing with it.


 drivers/atm/eni.c                  |    1 -
 drivers/media/video/zoran_driver.c |    1 -
 drivers/scsi/53c7xx.c              |    1 -
 3 files changed, 3 deletions(-)

diff --git a/drivers/atm/eni.c b/drivers/atm/eni.c
index 5aab7bd..8fccf01 100644
--- a/drivers/atm/eni.c
+++ b/drivers/atm/eni.c
@@ -912,7 +912,6 @@ static int start_rx(struct atm_dev *dev)
 		free_page((unsigned long) eni_dev->free_list);
 		return -ENOMEM;
 	}
-	memset(eni_dev->rx_map,0,PAGE_SIZE);
 	eni_dev->rx_mult = DEFAULT_RX_MULT;
 	eni_dev->fast = eni_dev->last_fast = NULL;
 	eni_dev->slow = eni_dev->last_slow = NULL;
diff --git a/drivers/media/video/zoran_driver.c b/drivers/media/video/zoran_driver.c
index 862a984..e10a9ee 100644
--- a/drivers/media/video/zoran_driver.c
+++ b/drivers/media/video/zoran_driver.c
@@ -562,7 +562,6 @@ jpg_fbuffer_alloc (struct file *file)
 			jpg_fbuffer_free(file);
 			return -ENOBUFS;
 		}
-		memset((void *) mem, 0, PAGE_SIZE);
 		fh->jpg_buffers.buffer[i].frag_tab = (u32 *) mem;
 		fh->jpg_buffers.buffer[i].frag_tab_bus =
 		    virt_to_bus((void *) mem);
diff --git a/drivers/scsi/53c7xx.c b/drivers/scsi/53c7xx.c
index 640536e..9c37943 100644
--- a/drivers/scsi/53c7xx.c
+++ b/drivers/scsi/53c7xx.c
@@ -3099,7 +3099,6 @@ allocate_cmd (Scsi_Cmnd *cmd) {
         real = get_zeroed_page(GFP_ATOMIC);
         if (real == 0)
         	return NULL;
-        memset((void *)real, 0, 4096);
         cache_push(virt_to_phys((void *)real), 4096);
         cache_clear(virt_to_phys((void *)real), 4096);
         kernel_set_cachemode((void *)real, 4096, IOMAP_NOCACHE_SER);

                 reply	other threads:[~2007-01-03 15:44 UTC|newest]

Thread overview: [no followups] expand[flat|nested]  mbox.gz  Atom feed

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=Pine.LNX.4.64.0701031033470.27478@localhost.localdomain \
    --to=rpjday@mindspring.com \
    --cc=linux-kernel@vger.kernel.org \
    /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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox

all inboxes | Powered by JetHome®